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WO2023169096A1 - 正极活性材料、二次电池、电池模块、电池包和用电装置 - Google Patents

正极活性材料、二次电池、电池模块、电池包和用电装置 Download PDF

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WO2023169096A1
WO2023169096A1 PCT/CN2023/073929 CN2023073929W WO2023169096A1 WO 2023169096 A1 WO2023169096 A1 WO 2023169096A1 CN 2023073929 W CN2023073929 W CN 2023073929W WO 2023169096 A1 WO2023169096 A1 WO 2023169096A1
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formula
active material
cathode active
compound represented
secondary battery
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PCT/CN2023/073929
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English (en)
French (fr)
Inventor
吴则利
韩昌隆
郭洁
黄磊
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宁德时代新能源科技股份有限公司
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Publication of WO2023169096A1 publication Critical patent/WO2023169096A1/zh

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/362—Composites
    • H01M4/366—Composites as layered products
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
    • H01M10/0566—Liquid materials
    • H01M10/0567—Liquid materials characterised by the additives
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/131—Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/485—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
    • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/60—Selection of substances as active materials, active masses, active liquids of organic compounds
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/60—Selection of substances as active materials, active masses, active liquids of organic compounds
    • H01M4/602—Polymers
    • H01M4/606—Polymers containing aromatic main chain polymers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
    • H01M50/204—Racks, modules or packs for multiple batteries or multiple cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/20—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders
    • H01M50/249—Mountings; Secondary casings or frames; Racks, modules or packs; Suspension devices; Shock absorbers; Transport or carrying devices; Holders specially adapted for aircraft or vehicles, e.g. cars or trains
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/028—Positive electrodes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present application relates to the field of battery technology, and more specifically, to positive active materials, secondary batteries and electrical devices.
  • Secondary batteries have the advantages of reliable working performance, no pollution, and no memory effect, so they are widely used. For example, as environmental protection issues become more and more important and new energy vehicles become more popular, the demand for power secondary batteries will grow explosively. However, as the application range of secondary batteries becomes more and more extensive, severe challenges are also posed to the performance of secondary batteries.
  • a positive electrode active material of a secondary battery for example, a transition metal oxide having a spinel structure, a layered structure, or a lithium-rich manganese base is used. When these positive electrode active materials are used, lower resistance and higher power of the positive electrode active material are expected.
  • the present application provides a cathode active material, a secondary battery and an electrical device.
  • the application can achieve low resistance and high power of the cathode active material.
  • this application proposes a cathode active material.
  • the cathode active material includes: an active component; and a coating layer containing an organic component, which covers at least part of the surface of the active component.
  • the organic component Including compounds represented by formula (1) and/or polymers formed by cross-linking polymerization of compounds represented by formula (1),
  • M is selected from a phosphorus atom, a boron atom or a sulfur atom
  • R is selected from an oxygen atom, a C1-C20 alkoxy group, a substituted or unsubstituted C6-C25 aromatic phenol group and a substituted or unsubstituted One or more C5-C25 heteroaromatic phenol groups
  • n represents the number of R groups, n is selected from 2 or 3.
  • the coating layer of the present application covers the surface of the active material, and the M atoms in the coating layer can interact with the oxygen atoms in the active material to stabilize the oxygen atoms and ensure the crystal lattice of the active component. Stability, and oxygen atoms are not easy to escape from the crystal lattice and cause side reactions with the electrolyte, thereby making the overall structural stability of the cathode active material better, thereby improving the cycle performance and capacity performance of the secondary battery; and stabilizing the cathode activity
  • the contact interface between the material and the electrolyte, the positive electrode solid electrolyte interface film CEI film formed on the surface of the positive electrode active material has better stability, resulting in better dynamic performance; M atoms may coordinate with fluorine ions in the electrolyte reaction, thereby effectively suppressing the generation of passivation material LiF, thereby reducing the DC impedance of the secondary battery, thereby improving the power performance of the secondary battery.
  • the active component includes at least one of the following components: Li s T q Ni a Co b Mn c M (1- abc) Y t , where 0 ⁇ s ⁇ 2.1, 0 ⁇ q ⁇ 2.1, and 0.9 ⁇ s+q ⁇ 2.1; 0 ⁇ a ⁇ 1, 0 ⁇ b ⁇ 1, 0 ⁇ c ⁇ 1, and 0.1 ⁇ a+b+c ⁇ 1; 1.8 ⁇ t ⁇ 3.5; T is selected from Na , one or more of K and Mg; M is selected from B, Mg, Al, Si, P, S, Ca, Sc, Ti, V, Cr, Fe, Cu, Zn, Sr, Y, Zr, Nb , one or more of Mo, Cd, Sn, Sb, Te, Ba, Ta, W, Yb, La, and Ce; Y is selected from one or more of O and F; xLi 2 MnO 3 ⁇ ( 1-x)LiMn y B 1-y O 2 , where, 0.1 ⁇ x ⁇ 0.9, 0.1 ⁇
  • M includes a phosphorus atom
  • the compound represented by formula (1) includes compounds represented by formula (I) and/or formula (II):
  • R 1 , R 2 , R 3 and R 4 are each independently selected from a hydrogen atom, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C6- C25 aryl, or substituted or unsubstituted C5-C25 heteroaryl; optionally, R 1 , R 2 , R 3 and R 4 are each independently selected from C1-C3 alkyl, phenyl, naphthyl , anthracenyl, phenanthrenyl, diphenyl or terphenyl.
  • the phosphorus atoms in this application interact with the oxygen in the active component to stabilize the cathode interface and improve the dynamics, and the phosphorus ions can coordinate with the fluoride ions in the electrolyte, effectively Suppresses the generation of passivation material LiF, thereby improving DC impedance. This can improve the power characteristics and cycle characteristics of the secondary battery.
  • the compound represented by formula (I) includes one or more compounds represented by formula (P-11) to formula (P-16):
  • Compounds represented by formula (II) include compounds represented by formula (P-21) and/or formula (P-22):
  • M includes a boron atom
  • the compound represented by formula (1) includes a compound represented by formula (III):
  • R 6 and R 7 are each independently selected from a hydrogen atom, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C6-C25 aryl group, or a substituted or unsubstituted C1-C25 aryl group.
  • the interaction between boron atoms and oxygen in the active component can stabilize the cathode interface and improve kinetics. Boron ions can coordinate with fluoride ions in the electrolyte to effectively suppress the generation of passivation LiF, thereby improving DC impedance. This can improve the power characteristics and cycle characteristics of the secondary battery.
  • the compound represented by formula (III) includes compounds represented by formula (B-1) to formula (B-3).
  • M includes a sulfur atom
  • the compound represented by formula (1) includes a compound represented by formula (IV):
  • R 5 is selected from a hydrogen atom, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C6-C25 aryl group, or a substituted or unsubstituted C5-C25 heteroaromatic group. group; optionally, each R 5 is independently selected from C1-C3 alkyl, phenyl, naphthyl, anthracenyl, phenanthrenyl, diphenyl or terphenyl.
  • Sulfur atoms interact with oxygen in the active component to stabilize the cathode interface and improve dynamics.
  • Boron ions can coordinate with fluoride ions in the electrolyte to effectively suppress the generation of passivation LiF, thereby improving DC impedance. This can improve the power characteristics and cycle characteristics of the secondary battery.
  • the compound represented by formula (IV) includes compounds represented by formula (S-1) and/or formula (S-2):
  • the coating layer includes a polymer formed by cross-linking polymerization of the compound represented by formula (1); the weight average molecular weight of the polymer is 500 Da to 2000 Da; optionally 1000 Da to 1500 Da; and/or coating The porosity of the layer ranges from 5% to 20%.
  • the weight average molecular weight of the polymer is within the above range, the viscosity of the coating layer formed by the polymer is relatively high, and its binding strength with the active component is relatively strong.
  • the coating layer is not easily It falls off from the surface of the active component, thereby providing long-term and stable protection to the active component and ensuring the cycle performance and capacity performance of the secondary battery.
  • the viscosity of the coating layer formed by the polymer will not be too high, the coating layer formed by it is easier to control, the thickness of the coating layer is more uniform, and the protective performance against active components is uniform.
  • the compound represented by formula (1) forms a polymer through cross-linking, the polymer may have a pore structure, so that the coating layer formed by the polymer has certain pores. The existence of these pores is conducive to the escape of active ions or embedded, Reduce DC impedance and improve dynamic performance.
  • the mass content of the organic component in the cathode active material is recorded as A%, 0.1 ⁇ A ⁇ 0.5; optionally, 0.2 ⁇ A ⁇ 0.4; and/or
  • the thickness of the cladding layer is 5 ⁇ m to 20 ⁇ m; optionally 5 ⁇ m to 10 ⁇ m.
  • the content of the organic component is within the above range.
  • the organic component can fully protect the active components and improve the cycle performance and capacity performance of the secondary battery; on the other hand, the organic component can make the package formed
  • the thickness of the coating layer is not too thick and the dynamic properties are improved, thereby further improving the power characteristics and cycle characteristics of the secondary battery.
  • a second aspect of the present application provides a secondary battery.
  • the secondary battery includes: a positive electrode plate, a negative electrode plate, an isolation film disposed between the positive electrode plate and the negative electrode plate, and an electrolyte.
  • the positive electrode plate includes The cathode active material as described in any embodiment of the first aspect of the application.
  • the electrolyte includes a first additive configured to form a film on the surface of the cathode active material, wherein the first additive includes an oxygen-containing heterocyclic element having at least one heterocyclic element among sulfur, phosphorus, and boron.
  • Ring compounds, and oxygen-containing heterocyclic compounds include mirror-image structures symmetrical with carbon-carbon single bonds. Therefore, the first additive in this application is a specific molecule with a symmetrical structure. These molecules can first be oxidized to form a film on the surface of the cathode active material in preference to the solvent of the electrolyte. Secondly, these molecules will also be physically adsorbed on the surface of the cathode active material.
  • the adsorption film formation has good uniformity and consistency, which can improve problems such as gas production during high-temperature storage of positive electrode active materials, and further improve cycle characteristics.
  • the surface of the positive active material is a coating layer, the coating layer is conducive to the adsorption of the first additive, further improving the film-forming effect of the first additive.
  • the first additive can also form a film on the surface of the negative electrode active material, which can also improve the film-forming performance on the surface of the negative electrode active material, thereby further improving the cycle characteristics of the secondary battery.
  • the first additive includes one or more compounds represented by formula (2) to formula (5):
  • the mass content of the organic component in the cathode active material is recorded as A%; based on the total mass of the electrolyte, the mass content of the first additive in the electrolyte is expressed as is B%, where the secondary battery satisfies: 0.5 ⁇ B/A ⁇ 2. Therefore, the first additive in the electrolyte of the present application and the organic components in the cathode active material cooperate with each other, which is beneficial to forming a uniform and dense CEI film on the surface of the cathode active material, and acts on the active components in the cathode active material.
  • the mass content of the first additive in the electrolyte is recorded as B%, and 0.10 ⁇ B ⁇ 0.70.
  • the first additive includes at least two of the compounds represented by formula (2) to formula (5); based on the total molar amount of the first additive, one of the compounds in the first additive
  • the ratio of the molar content of the compound to the molar content of another compound is recorded as C, 1 ⁇ C ⁇ 2; optionally, 1.2 ⁇ C ⁇ 1.5. Therefore, this application can make the CEI film formed by the first additive on the surface of the positive electrode active material richer in components through the cooperation of the two compounds, and the structure of the CEI film is more stable, and is conducive to the embedding or embedding of active ions. out, thereby improving the cycle performance of the secondary battery.
  • the first additive may also be able to form a component-rich SEI film on the surface of the negative electrode active material, thereby further improving the cycle performance of the secondary battery.
  • This application proposes an electrical device, including a secondary battery as described in any embodiment of the second aspect of this application.
  • FIG. 1 is a schematic diagram of a secondary battery according to an embodiment of the present application.
  • FIG. 2 is an exploded view of the secondary battery according to the embodiment of the present application shown in FIG. 1 .
  • FIG. 3 is a schematic diagram of a battery module according to an embodiment of the present application.
  • Figure 4 is a schematic diagram of a battery pack according to an embodiment of the present application.
  • FIG. 5 is an exploded view of the battery pack according to an embodiment of the present application shown in FIG. 4 .
  • FIG. 6 is a schematic diagram of a power consumption device using a secondary battery as a power source according to an embodiment of the present application.
  • Ranges disclosed herein are defined in terms of lower and upper limits. A given range is defined by selecting a lower limit and an upper limit that define the boundaries of the particular range. Ranges defined in this manner may be inclusive or exclusive of the endpoints, and may be arbitrarily combined, that is, any lower limit may be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a particular parameter, understand that ranges of 60-110 and 80-120 are also expected. Additionally, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5.
  • the numerical range “ab” represents an abbreviated representation of any combination of real numbers between a and b, where a and b are both real numbers.
  • the numerical range “0-5" means that all real numbers between "0-5" have been listed in this article, and "0-5" is just an abbreviation of these numerical combinations.
  • a certain parameter is an integer ⁇ 2
  • the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially.
  • step (c) means that step (c) may be added to the method in any order.
  • the method may include steps (a), (b) and (c). , may also include steps (a), (c) and (b), may also include steps (c), (a) and (b), etc.
  • condition "A or B” is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists) ; Or both A and B are true (or exist).
  • alkoxy refers to a group in which an alkyl group is bonded to an oxygen atom by a single bond.
  • the alkoxy group can be C1-C20 alkoxy, C1-C15 alkoxy, C1-C10 alkoxy, C1-C8 alkoxy, C1-C5 alkoxy, C2-C6 alkoxy.
  • alkoxy can include methoxy, ethoxy, propoxy, butoxy, isobutoxy, sec-butoxy, tert-butoxy, cyclobutoxy, pentoxy , isopentyloxy, neopentyloxy, tert-pentyloxy, cyclopentyloxy.
  • aryl refers to a closed aromatic ring or ring system.
  • the aryl group can be C6-C50 aryl, C6-C40 aryl, C6-C30 aryl, C6-C20 aryl, C6-C10 aryl, where C6-C30 aryl refers to a group containing 6-30 aryl groups. Carbon atoms that form a ring.
  • aryl groups include phenyl, naphthyl, phenanthrenyl, anthracenyl, biphenyl, triphenylene, pyrenyl, spirobifluorenyl, perylene, indenyl, azulenyl, and the like.
  • aromatic heterocyclyl means that the carbon atoms in the ring of the aryl group are replaced by heteroatoms.
  • the heteroatoms may include nitrogen atoms, oxygen atoms, sulfur atoms, etc.
  • aromatic phenol group refers to a group formed by combining a carbon atom in the square ring of an aryl group with a hydroxyl group.
  • the aromatic phenol group can be a C6-C25 aromatic phenol group, a C6-C20 aromatic phenol group, a C6-C15 aromatic phenol group, or a C6-C10 aromatic phenol group.
  • the aromatic phenol group may include phenyl hydroxyl, naphthyl hydroxyl, phenanthrene hydroxyl, anthracene hydroxyl, biphenyl hydroxyl, triphenylene hydroxyl, pyrene hydroxyl, spirobifluorene hydroxyl, perylene hydroxyl, indene hydroxyl, azulene hydroxyl, and the like.
  • heteromatic phenol group means that the carbon atoms in the square ring are replaced by heteroatoms.
  • the heteroatoms can include nitrogen atoms, oxygen atoms, sulfur atoms, etc.
  • the heteroaromatic phenol group may include azobenzene hydroxyl, azonaphthalene Hydroxy, azazaphenanthrene hydroxyl, azoanthracene hydroxyl, azabiphenyl hydroxyl, azatriphenylene hydroxyl, azapyrene hydroxyl, azaspirobifluorene hydroxyl, azaperylene hydroxyl, azaindene hydroxyl, azazazulene hydroxyl , heterothiophenyl hydroxyl, heterothionaphthalene hydroxyl, heterothiophenanthrene hydroxyl, heterothionthane hydroxyl, heterothiobiphenyl hydroxyl, heterooxyphenyl hydroxyl, heterooxynaphthyl hydroxyl,
  • the substituent may be a halogen atom or the like.
  • the stability of its material structure has a direct impact on the performance of secondary batteries.
  • oxygen atoms are easily detached from the lattice position, resulting in instability of the lattice structure; and the detached oxygen atoms have high reactivity and can react with the electrolyte on the surface of the positive active material. Side reactions lead to instability of the interface film on the surface of the cathode active material.
  • the structural stability of the cathode active material itself may be poor, especially under high temperature and high pressure systems, it is easy to decompose and release a large amount of oxygen, further deteriorating the performance of the cathode active material. Secondary batteries using this type of cathode active material have poor cycle performance and rapid capacity fading.
  • this application starts from the perspective of protecting the cathode active material, and covers the surface of the cathode active material with a coating layer to stabilize the structure of the cathode active material, improve the cycle performance of the cathode active material, and improve the use of the cathode active material.
  • the cycle performance and capacity performance of the secondary battery of the material can be improved at the same time, and its power performance can be improved at the same time.
  • this application proposes a cathode active material.
  • the cathode active material includes an active component and a coating layer; the coating layer covers at least part of the surface containing the active component and can act on the active component. Excellent protective effect.
  • the coating layer contains organic components, and the organic components include compounds represented by formula (1) and/or polymers formed by cross-linking and polymerization of compounds represented by formula (1),
  • M is selected from a phosphorus atom, a boron atom or a sulfur atom
  • R is selected from one or more of oxygen atoms, C1-C20 alkoxy groups, substituted or unsubstituted C6-C25 aromatic phenol groups, and substituted or unsubstituted C5-C25 heteroaromatic phenol groups;
  • n represents the number of R groups, n is selected from 2 or 3; the value of n depends on the type of atom taken by M.
  • this application can significantly improve the structural stability of the cathode active material by coating the above-mentioned active component with the above-mentioned organic component.
  • the positive electrode active material When used in secondary batteries, it can improve the cycle of the secondary battery. performance and capacity performance, and the ability to improve its power characteristics.
  • Oxygen atoms are usually included in the active ingredients.
  • the coating layer covers the surface of the active material.
  • the M atoms in the coating layer can interact with the oxygen atoms in the active material to stabilize the oxygen atoms and ensure the lattice stability of the active components.
  • the positive electrode solid electrolyte interface film CEI film formed on the surface of the positive electrode active material has better stability, resulting in better dynamic performance; M atoms may undergo coordination reactions with fluorine ions in the electrolyte, which can effectively inhibit The passivation material LiF is generated, thereby reducing the DC resistance of the secondary battery, thereby improving the power performance of the secondary battery.
  • the active component can provide capacity for the secondary battery and may include at least one of the following materials: layered structure cathode active materials (such as ternary, lithium/sodium nickelate, lithium/sodium cobaltate, Materials such as lithium/sodium manganate, lithium/sodium rich layered and rock salt phase layered materials), spinel structure cathode active materials (such as spinel lithium manganate, spinel lithium nickel manganate, lithium-rich spinel Spar lithium manganate and lithium nickel manganate, etc.), olivine type phosphate active materials.
  • the cathode active material may be a layered structure and/or a spinel structure.
  • the general formula of the layered structure cathode active material is: Li s T q Ni a Co b Mn c M (1-abc) Y t , where 0 ⁇ s ⁇ 2.1, 0 ⁇ q ⁇ 2.1, and 0.9 ⁇ s+q ⁇ 2.1; 0 ⁇ a ⁇ 1, 0 ⁇ b ⁇ 1, 0 ⁇ c ⁇ 1, and 0.1 ⁇ a+b+c ⁇ 1; 1.8 ⁇ t ⁇ 3.5; T is selected from Na, K, Mg One or more of them; M is selected from B, Mg, Al, Si, P, S, Ca, Sc, Ti, V, Cr, Fe, Cu, Zn, Sr, Y, Zr, Nb, Mo, Cd , one or more of Sn, Sb, Te, Ba, Ta, W, Yb, La, and Ce; Y is selected from one or more of O and F.
  • the layered structure cathode active material is: LiNi a Co b Mn c Y 2 .
  • the layered structure cathode active material may include lithium cobalt oxide LCO, lithium nickel oxide LNO, lithium manganate LMO, LiNi 1/3 Co 1/3 Mn 1/3 O 2 (NCM333), LiNi 0.8 Co 0.1 Mn 0.1 One or more of O 2 (NCM811) and LiNi 0.5 Co 0.2 Mn 0.3 O 2 (NCM523).
  • the general formula of the spinel structure cathode active material is: xLi 2 MnO 3 ⁇ (1-x)LiMn y B 1- y O 2 , where, 0.1 ⁇ x ⁇ 0.9, 0.1 ⁇ y ⁇ 0.9, B is selected from Ni, Co, B, Mg, Al, Si, P, S, Ca, Sc, Ti, V, Cr, Fe, Cu, Zn, Sr, Y, Zr, Nb, Mo, Cd, Sn, Sb , Te, Ba, Ta, W, Yb, La, Ce; optionally, B is selected from one or more of Na, K, Mg.
  • the spinel structure cathode active materials include LiMn 2 O 4 , LiNi 0.5 Mn 1.5 O 4 , LiCr 0.3 Mn 1.7 O 4 , Li 1.1 Al 0.1 Mn 1.9 O 4 , Li 2 Mn 2 O 4 and Li 1.5 Mn One or more of 2 O 4 .
  • the general formula of the olivine-type phosphate active material is: Li x A y Me a M b P 1-c X c Y z , where 0 ⁇ x ⁇ 1.3, 0 ⁇ y ⁇ 1.3, and 0.9 ⁇ x+y ⁇ 1.3; 0.9 ⁇ a ⁇ 1.5, 0 ⁇ b ⁇ 0.5, and 0.9 ⁇ a+b ⁇ 1.5; 0 ⁇ c ⁇ 0.5; 3 ⁇ z ⁇ 5;
  • A is selected from one of Na, K and Mg One or more;
  • Me is selected from one or more of Mn, Fe, Co, and Ni;
  • M is selected from B, Mg, Al, Si, P, S, Ca, Sc, Ti, V, Cr, Cu, One or more of Zn, Sr, Y, Zr, Nb, Mo, Cd, Sn, Sb, Te, Ba, Ta, W, Yb, La, and Ce;
  • X is selected from S, Si, Cl, B, One or more of C and N;
  • Y is selected from one or more
  • the coating layer covers the surface of the active component. It can cover the entire surface of the active component, so that the active component can be fully protected; it can also cover part of the surface of the active component. This can ensure that the DC impedance of the secondary battery is relatively low on the basis of protecting the active components, which is conducive to both Cycle performance and power characteristics of secondary batteries.
  • the coating layer includes organic components, which can be monomer structures of small molecules or macromolecular polymers formed by cross-linking between monomer structures. The monomer structure of small molecules makes it easier to control the film thickness; the film layer formed by macromolecular polymers is more uniform and dense, and has better protection against active components.
  • R is selected from one of an oxygen atom, a C1-C10 alkoxy group, a substituted or unsubstituted C6-C10 aromatic phenol group, and a substituted or unsubstituted C5-C10 heteroaromatic phenol group.
  • R is selected from C1-C3 alkyl, phenyl, naphthyl, anthracenyl, phenanthrenyl, diphenyl or terphenyl.
  • M includes a phosphorus atom.
  • Phosphorus atoms interact with oxygen in the active component to stabilize the cathode interface and improve dynamics.
  • Phosphorus ions can coordinate with fluoride ions in the electrolyte to effectively inhibit the generation of passivation LiF, thereby improving DC impedance. This can improve the power characteristics and cycle characteristics of the secondary battery.
  • the compounds represented by formula (1) include compounds represented by formula (I):
  • R 1 and R 2 , R 3 and R 4 are each independently selected from a hydrogen atom, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C6-C25 aryl group, or Substituted or unsubstituted C5-C25 heteroaryl;
  • R 1 and R 2 , R 3 and R 4 are each independently selected from C1-C3 alkyl, phenyl, naphthyl, anthracenyl, phenanthrenyl, diphenyl or terphenyl.
  • the compound represented by formula (I) includes one or more compounds represented by formula (P-11) to formula (P-16):
  • the compounds represented by formula (1) include compounds represented by formula (II):
  • R 3 and R 4 are each independently selected from a hydrogen atom, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C6-C25 aryl group, or a substituted or unsubstituted C1-C25 aryl group.
  • C5-C25 heteroaromatic group optionally, R 3 and R 4 are each independently selected from C1-C3 alkyl, phenyl, naphthyl, anthracenyl, phenanthrenyl, diphenyl or terphenyl.
  • the compound represented by formula (I) includes one or more compounds represented by formula (P-21) and formula (P-22):
  • the compound represented by formula (1) includes the compound represented by formula (I) and the compound represented by formula (II).
  • M includes boron atoms.
  • the interaction between boron atoms and oxygen in the active component can stabilize the cathode interface and improve kinetics.
  • Boron ions can coordinate with fluoride ions in the electrolyte to effectively suppress the generation of passivation LiF, thereby improving DC impedance. This can improve the power characteristics and cycle characteristics of the secondary battery.
  • the compounds represented by formula (1) include compounds represented by formula (III):
  • R 6 and R 7 are each independently selected from a hydrogen atom, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C6-C25 aryl group, or a substituted or unsubstituted C1-C25 aryl group.
  • C5-C25 heteroaromatic group optionally, R 6 and R 7 are each independently selected from C1-C3 alkyl, phenyl, naphthyl, anthracenyl, phenanthrenyl, diphenyl or terphenyl.
  • the compound represented by formula (III) includes one or more compounds represented by formula (B-1) to formula (B-3):
  • M includes a sulfur atom.
  • Sulfur atoms interact with oxygen in the active component to stabilize the cathode interface and improve dynamics.
  • Boron ions can coordinate with fluoride ions in the electrolyte to effectively suppress the generation of passivation LiF, thereby improving DC impedance. This can improve the power characteristics and cycle characteristics of the secondary battery.
  • the compounds represented by formula (1) include compounds represented by formula (IV):
  • R 5 is selected from a hydrogen atom, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C6-C25 aryl group, or a substituted or unsubstituted C5-C25 heteroaromatic group. base;
  • R 5 is each independently selected from C1-C3 alkyl, phenyl, naphthyl, anthracenyl, phenanthrenyl, diphenyl or terphenyl.
  • the compounds represented by formula (IV) include compounds represented by formula (S-1) and/or formula (S-2):
  • the inventors of the present application have discovered that when the cathode active material satisfies one or more of the following conditions, the cycle performance, capacity performance and power performance of the secondary battery can be further improved.
  • the polymer has a weight average molecular weight of 500 Da to 2000 Da.
  • the viscosity of the coating layer formed by the polymer is relatively high, and its binding strength with the active component is relatively strong.
  • the coating layer is not easily It falls off from the surface of the active component, thereby providing long-term and stable protection to the active component and ensuring the cycle performance and capacity performance of the secondary battery.
  • the viscosity of the coating layer formed by the polymer will not be too high, the coating layer formed by it is easier to control, the thickness of the coating layer is more uniform, and the protective performance against active components is uniform.
  • the polymer has a weight average molecular weight of 1000 Da to 1500 Da.
  • the weight average molecular weight of the polymer is 500Da, 600Da, 800Da, 900Da, 1000Da, 1200Da, 1500Da, 1800Da, 2000Da or a range consisting of any two of the above values.
  • the cladding layer has a porosity of 5% to 20%.
  • the polymer may have a pore structure, so that the coating layer formed by the polymer has certain pores.
  • the existence of these pores is conducive to the escape of active ions. Or embedded to reduce DC impedance and improve dynamic performance.
  • the porosity of the coating layer can be 5%, 6%, 8%, 10%, 12%, 15%, 16%, 18%, 19%, 20%, or any two of the above values. scope.
  • the mass content of the organic component in the cathode active material is recorded as A%, 0.1 ⁇ A ⁇ 0.5; optionally 0.2 ⁇ A ⁇ 0.4.
  • the content of the organic component is within the above range.
  • the organic component can fully protect the active components and improve the cycle performance and capacity performance of the secondary battery; on the other hand, the organic component can make the package formed
  • the thickness of the coating layer is not too thick and the dynamic properties are improved, thereby further improving the power characteristics and cycle characteristics of the secondary battery.
  • the mass content of the organic component in the cathode active material, recorded as A% can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, or a range consisting of any two of the above values.
  • the thickness of the coating layer is 5 ⁇ m to 20 ⁇ m; optionally, the thickness is 5 ⁇ m to 10 ⁇ m.
  • the thickness of the coating layer is within the above range.
  • the organic components can fully protect the active components and improve the cycle performance and capacity performance of the secondary battery.
  • the coating formed by the organic components can The thickness of the coating layer is not too thick and the dynamic properties are improved, thereby further improving the power characteristics and cycle characteristics of the secondary battery.
  • the thickness of the coating layer may be 5 ⁇ m, 6 ⁇ m, 8 ⁇ m, 10 ⁇ m, 12 ⁇ m, 15 ⁇ m, 16 ⁇ m, 18 ⁇ m, 20 ⁇ m, or a range consisting of any two of the above values.
  • the present application provides a secondary battery, which includes a positive electrode plate, a negative electrode plate, a separation film disposed between the positive electrode plate and the negative electrode plate, and an electrolyte
  • the positive electrode sheet includes a positive electrode film layer
  • the positive electrode film layer includes the positive electrode active material as described in any embodiment of the first aspect of this application.
  • the active components in the cathode active material can significantly improve the cycle performance, capacity performance and power performance of the secondary battery through coating with organic components.
  • the positive electrode sheet includes a positive electrode current collector and a positive electrode film layer disposed on at least one surface of the positive electrode current collector.
  • the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode film layer is disposed on any one or both of the two opposite surfaces of the positive electrode current collector.
  • the positive electrode film layer optionally further includes a positive electrode conductive agent.
  • a positive electrode conductive agent includes superconducting carbon, conductive graphite, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon.
  • the mass percentage of the cathode conductive agent is less than 5%.
  • the positive electrode film layer optionally further includes a positive electrode binder.
  • the positive electrode binder may include polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), vinylidene fluoride-tetrafluoroethylene-propylene. Terpolymers, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymers, tetrafluoroethylene-hexafluoropropylene copolymers and fluorine-containing acrylate resins One or a combination of more.
  • the mass percentage of the cathode binder is less than 5% based on the total mass of the cathode film layer.
  • the positive electrode current collector may be a metal foil or a composite current collector.
  • the metal foil aluminum foil or aluminum alloy foil can be used.
  • the composite current collector may include a polymer material base layer and a metal material layer formed on at least one surface of the polymer material base layer.
  • the metal material may include aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver. and a combination of one or more silver alloys.
  • the polymer material base layer may include polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate ( One or a combination of one or more of PBT), polystyrene (PS) and polyethylene (PE).
  • the positive electrode film layer is usually formed by coating the positive electrode slurry on the positive electrode current collector, drying and cold pressing.
  • the cathode slurry is usually formed by dispersing the cathode active material, optional conductive agent, optional binder and any other components in a solvent and stirring evenly.
  • the solvent may be N-methylpyrrolidone (NMP), but is not limited thereto.
  • the negative electrode sheet includes a negative electrode current collector and a negative electrode film layer disposed on at least one surface of the negative electrode current collector, where the negative electrode film layer includes a negative electrode active material.
  • the negative electrode current collector has two opposite surfaces in its own thickness direction, and the negative electrode film layer is disposed on any one or both of the two opposite surfaces of the negative electrode current collector.
  • the negative electrode current collector may be a metal foil or a composite current collector.
  • the composite current collector may include a polymer material base layer and a metal layer formed on at least one surface of the polymer material base material.
  • the composite current collector can be formed by forming metal materials (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as polypropylene (PP), polyterephthalate It is formed on substrates such as ethylene glycol ester (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).
  • PP polypropylene
  • PBT polybutylene terephthalate
  • PS polystyrene
  • PE polyethylene
  • the negative active material may be a negative active material known in the art for batteries.
  • the negative active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, and the like.
  • the silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon carbon composites, silicon nitrogen composites and silicon alloys.
  • the tin-based material may be selected from at least one of elemental tin, tin oxide compounds and tin alloys.
  • the present application is not limited to these materials, and other traditional materials that can be used as battery negative electrode active materials can also be used. Only one type of these negative electrode active materials may be used alone, or two or more types may be used in combination.
  • the negative electrode film layer optionally further includes a negative electrode binder.
  • the negative electrode binder can be selected from styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), At least one of polymethacrylic acid (PMAA) and carboxymethyl chitosan (CMCS).
  • the negative electrode film layer optionally further includes a conductive agent.
  • the conductive agent may be selected from at least one of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.
  • the negative electrode film layer optionally includes other auxiliaries, such as thickeners (such as sodium carboxymethylcellulose (CMC-Na)) and the like.
  • thickeners such as sodium carboxymethylcellulose (CMC-Na)
  • the negative electrode sheet can be prepared by dispersing the above-mentioned components for preparing the negative electrode sheet, such as negative active materials, conductive agents, binders and any other components in a solvent (such as deionized water) to form a negative electrode slurry; the negative electrode slurry is coated on the negative electrode current collector, and after drying, cold pressing and other processes, the negative electrode piece can be obtained.
  • a solvent such as deionized water
  • the electrolyte plays a role in conducting ions between the positive and negative electrodes.
  • the type of electrolyte in this application can be selected according to needs.
  • the electrolyte can be liquid, gel, or completely solid.
  • the electrolyte is an electrolyte solution.
  • the electrolyte solution includes electrolyte salts and solvents.
  • the electrolyte is an electrolyte solution.
  • the electrolyte solution includes electrolyte salts and solvents.
  • the lithium salt may include lithium hexafluorophosphate (LiPF 6 ), lithium tetrafluoroborate (LiBF 4 ), lithium perchlorate (LiClO 4 ), lithium hexafluoroarsenate (LiAsF 6 ), lithium bisfluorosulfonimide (LiFSI), lithium bistrifluoromethanesulfonyl imide (LiTFSI), lithium trifluoromethanesulfonate (LiTFS), lithium difluoromethanesulfonate borate (LiDFOB), lithium dioxalatoborate (LiBOB), lithium difluorophosphate (LiPO 2 F 2 ), lithium difluorodioxalate phosphate (LiDFOP) and lithium tetrafluorooxalate phosphate (LiTFOP).
  • LiPF 6 lithium hexafluorophosphate
  • LiBF 4 lithium tetrafluoroborate
  • the organic solvent may include ethylene carbonate (EC), propylene carbonate (PC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dimethyl carbonate, Propyl ester (DPC), methylpropyl carbonate (MPC), ethyl propyl carbonate (EPC), butylene carbonate (BC), methyl formate (MF), methyl acetate (MA), ethyl acetate (EA), Propyl acetate (PA), methyl propionate (MP), ethyl propionate (EP), propyl propionate (PP), methyl butyrate (MB), ethyl butyrate (EB), 1,4 - One or a combination of butyrolactone (GBL), sulfolane (SF), dimethyl sulfone (MSM), methyl ethyl sulfone (EMS) and diethyl sulfone (ESE).
  • EC
  • the electrolyte optionally further includes additives.
  • additives may include negative electrode film-forming additives, positive electrode film-forming additives, and may also include additives that can improve certain properties of the battery, such as additives that improve battery overcharge performance, additives that improve battery high-temperature or low-temperature performance, etc.
  • the inventor found that when a specific additive, such as a first additive, is added to the electrolyte, the film-forming performance can be significantly improved, thereby improving the cycle performance of the secondary battery.
  • the properties of the first additive are as follows: the first additive is configured to form a film on the surface of the cathode active material, wherein the first additive includes an oxygen-containing heterocyclic compound having at least one heterocyclic element among sulfur, phosphorus, and boron. , and the oxygen-containing heterocyclic compound includes a mirror image structure symmetrical with a carbon-carbon single bond.
  • the first additive is a specific molecule with a symmetrical structure.
  • these molecules can first be oxidized to form a film on the surface of the positive active material prior to the solvent of the electrolyte. Secondly, these molecules will also be physically adsorbed on the surface of the positive active material. Due to their structure, Symmetry, good uniformity and consistency of its adsorption film formation, can improve problems such as gas production during high-temperature storage of positive electrode active materials, and further improve cycle characteristics. Moreover, since the surface of the positive active material is a coating layer, the coating layer is conducive to the adsorption of the first additive, further improving the film-forming effect of the first additive.
  • the first additive can also form a film on the surface of the negative active material, The film-forming performance on the surface of the negative electrode active material can also be improved, thereby further improving the cycle characteristics of the secondary battery.
  • the first additive includes sulfur; specifically, the first additive includes one or more compounds represented by formulas (2) to (5):
  • the above-mentioned additives are specific molecules containing sulfur atoms and having a symmetrical structure. These molecules can be oxidized to form films on the material surface in preference to solvents. Secondly, these molecules will also be physically adsorbed on the surface of the cathode active material. Due to the symmetry of their structure, they The adsorption film formation has good uniformity and consistency, which can improve the gas production problem of high-temperature storage of positive electrode active materials and further improve cycle characteristics.
  • the first additive includes at least two of the compounds represented by formula (2) to formula (5); based on the total molar amount of the first additive, the The ratio of the molar content of one compound to the molar content of the other compound is recorded as C, 1 ⁇ C ⁇ 2; optionally, 1.2 ⁇ C ⁇ 1.5.
  • the CEI film formed by the first additive on the surface of the positive electrode active material can be richer in components, the structure of the CEI film is more stable, and it is conducive to the insertion or extraction of active ions, thus improving the Cycling performance of secondary batteries.
  • the first additive may also be able to form a component-rich SEI film on the surface of the negative electrode active material, thereby further improving the cycle performance of the secondary battery.
  • the specific structural formulas of the above-mentioned phosphorus-containing additives are similar to formulas (2) to (5). The difference is that the sulfur element in formulas (2) to (5) is replaced by phosphorus. Element, specifically, its structural formula can be shown as formula (6):
  • the specific structural formulas of the above-mentioned boron-containing additives are similar to formulas (2) to (5). The difference is that the sulfur element in formulas (2) to (5) is replaced by boron. Element, specifically, its structural formula can be shown as formula (7):
  • the mass content of the first additive in the electrolyte is recorded as B%, where the secondary battery satisfies: 0.5 ⁇ B/A ⁇ 2.
  • the first additive in the electrolyte and the organic components in the cathode active material cooperate with each other to help form a uniform and dense CEI film on the surface of the cathode active material, which plays an excellent protective role for the active components in the cathode active material.
  • the mass content of the first additive in the electrolyte is recorded as B%, 0.10 ⁇ B ⁇ 0.70.
  • the secondary battery further includes a separator film.
  • a separator film There is no particular restriction on the type of isolation membrane in this application. Any well-known porous structure isolation membrane with good chemical stability and mechanical stability can be used.
  • the material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride.
  • the isolation film can be a single-layer film or a multi-layer composite film, with no special restrictions. When the isolation film is a multi-layer composite film, the materials of each layer can be the same or different, and there is no particular limitation.
  • the positive electrode piece, the negative electrode piece and the separator film can be made into an electrode assembly through a winding process or a lamination process.
  • This application has no particular limitation on the shape of the secondary battery, which can be cylindrical, square or any other shape. As shown in FIG. 1 , a square-structured secondary battery 5 is shown as an example.
  • the outer package may include a housing 51 and a cover 53 .
  • the housing 51 may include a bottom plate and side plates connected to the bottom plate, and the bottom plate and the side plates enclose a receiving cavity.
  • the housing 51 has an opening communicating with the accommodation cavity, and the cover plate 53 is used to cover the opening to close the accommodation cavity.
  • the positive electrode piece, the negative electrode piece and the isolation film can be formed into the electrode assembly 52 through a winding process or a lamination process.
  • the electrode assembly 52 is packaged in the containing cavity.
  • the electrolyte soaks into the electrode assembly 52 .
  • the number of electrode assemblies 52 contained in the secondary battery 5 can be one or more, and can be adjusted according to needs.
  • the positive electrode sheet, the separator, the negative electrode sheet, and the electrolyte may be assembled to form a secondary battery.
  • the positive electrode sheet, isolation film, and negative electrode sheet can be formed into an electrode assembly through a winding process or a lamination process.
  • the electrode assembly is placed in an outer package, dried, and then injected with electrolyte. After vacuum packaging, standing, and Through processes such as formation and shaping, secondary batteries are obtained.
  • the secondary batteries according to the present application can be assembled into a battery module.
  • the number of secondary batteries contained in the battery module can be multiple, and the specific number can be adjusted according to the application and capacity of the battery module.
  • FIG. 3 is a schematic diagram of the battery module 4 as an example.
  • a plurality of secondary batteries 5 may be arranged in sequence along the length direction of the battery module 4 .
  • the plurality of secondary batteries 5 can be fixed by fasteners.
  • the battery module 4 may further include a housing having a receiving space in which a plurality of secondary batteries 5 are received.
  • the above-mentioned battery modules can also be assembled into a battery pack, and the number of battery modules contained in the battery pack can be adjusted according to the application and capacity of the battery pack.
  • the battery pack 1 may include a battery box and a plurality of battery modules 4 arranged in the battery box.
  • the battery box includes an upper box 2 and a lower box 3 .
  • the upper box 2 is used to cover the lower box 3 and form a closed space for accommodating the battery module 4 .
  • Multiple battery modules 4 can be arranged in the battery box in any manner.
  • the present application provides an electrical device.
  • the electrical device includes at least one of a secondary battery, a battery module and a battery pack of the present application.
  • Secondary batteries, battery modules and battery packs can be used as power sources for power-consuming devices, and can also be used as energy storage units for power-consuming devices.
  • Electric devices can be, but are not limited to, mobile devices (such as mobile phones, laptops, etc.), electric vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, and electric golf balls). vehicles, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc.
  • the electrical device can select secondary batteries, battery modules or battery packs according to its usage requirements.
  • FIG. 6 is a schematic diagram of an electrical device as an example.
  • the electric device 6 is a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or the like.
  • a battery pack 1 or a battery module can be used.
  • the power-consuming device may be a mobile phone, a tablet computer, a laptop computer, etc.
  • the electrical device is usually required to be light and thin, and secondary batteries can be used as power sources.
  • Example 1 of Table 1 Dissolve the organic components shown in Example 1 of Table 1 into the ethyl acetate solvent, prepare an organic solution with a concentration of 10%, and add the active component (LiNi 0.8 Co 0.1 Mn 0.1 O 2 ) to the above solution.
  • the active component LiNi 0.8 Co 0.1 Mn 0.1 O 2
  • Mix at a mass ratio of 1:10 stir and disperse for 4 hours in an environment of 40°C to 50°C, add a certain amount of FeCl 3 initiator to further initiate cross-linking coating of the organic components, continue stirring for 4 hours, filter to remove the solvent, and then at 80 Dry in a vacuum oven at °C for 8 hours to obtain the active component coated with organic components, that is, the positive active material.
  • An aluminum foil with a thickness of 12 ⁇ m was used as the positive electrode current collector.
  • the positive electrode active material prepared in the above (1), the conductive agent Super P, and the binder polyvinylidene fluoride (PVDF) were mixed in N-methylpyrrolidone (NMP) to prepare a positive electrode slurry.
  • NMP N-methylpyrrolidone
  • the solid content in the positive electrode slurry is 50wt%, and the mass ratio of LiN i0.8 Co 0.1 Mn 0.1 O 2 , Super P, and PVDF in the solid content is 8:1:1.
  • the cathode slurry The material is coated on the current collector aluminum foil and dried at 85°C, then cold pressed, then trimmed, cut into pieces, and slit, and then dried under vacuum conditions at 85°C for 4 hours to make the positive electrode piece.
  • a copper foil with a thickness of 8 ⁇ m was used as the negative electrode current collector.
  • the non-aqueous organic solvents ethylene carbonate EC and diethyl carbonate DMC are mixed at a volume ratio of 1:1 to obtain an electrolyte solvent, and then the lithium salt and the mixed solvent are mixed to form The electrolyte with a lithium salt concentration of 1mol/L.
  • PE polyethylene film
  • Examples 2 to 14 adopt a method similar to Example 1 to prepare lithium ion batteries. The difference from Example 1 is that the types and amounts of organic components and electrolyte additives are adjusted in Examples 2 to 14.
  • Examples 15 to 18 adopt a method similar to Example 10 to prepare lithium ion batteries. The difference from Example 10 is that Examples 15 to 18 adjust the porosity of the coating layer formed by the organic component.
  • Examples 19 to 20 adopt a method similar to Example 10 to prepare lithium ion batteries. The difference from Example 10 is that Examples 19 to 20 adjust the types of electrolyte additives to be multiple.
  • Examples 21 to 23 adopt a method similar to Example 10 to prepare lithium ion batteries. The difference from Example 10 is that the organic components in Examples 21 to 23 are adjusted to small molecule monomer compounds.
  • Comparative Example 1 adopts a method similar to Example 1 to prepare a lithium-ion battery. The difference from Example 1 is that the organic component and the first additive are not provided in Comparative Example 1.
  • Example 2 The parameters of Example 2 to Example 23 and Comparative Example 1 are shown in Table 1:
  • Example 1 25°C, capacity retention rate/% after 600 cycles Volume growth rate after 30 days storage at 60°C/% DCR/m ⁇ Comparative example 1 77.2 15.9 20.3 Example 1 92.3 10.9 18.8 Example 2 91.3 12.1 19.1 Example 3 90.8 11.9 19.4 Example 4 91.2 11.3 19.9 Example 5 90.4 14.1 19.3 Example 6 91.8 10.6 20.1 Example 7 88.8 13.8 20.1 Example 8 89.2 10.1 20.8 Example 92.5 10.5 18.9 Example 10 94.7 9.9 20.1 Example 11 94.5 9.5 21.4 Example 12 92.4 10.8 18.9 Example 13 94.6 9.4 twenty three Example 14 94.5 10.3 20.8 Example 15 96.1 9.9 19.3 Example 16 96.3 10.2 19.4 Example 17 96.1 10.5 19.1 Example 18 96.0 10.4 19.5 Example 19 96.3 10.1 19.7 Example 20 96.5 10.0 19.6 Example 21 93.4 10.0 18.3 Example 22 92.7 9.6 18.7 Example 23 92.8 9.8 18.4
  • the active component is not coated, the structural stability of the active component is poor, and the cycle performance of the secondary battery is relatively poor.
  • the surface of the active component is coated with an organic component, which can protect the active component and improve the power characteristics (lower DC impedance) and cycle characteristics of the secondary battery.
  • the organic components are in cross-linked polymerization state (Example 1 to Example 20) and monomer state (Example 21 to Example 23), which can play a protective role in the active components.
  • the added content of the organic component is within a specific range of 0.1 ⁇ A ⁇ 0.5; especially 0.2 ⁇ A ⁇ 0.4, which can further improve the cycle characteristics and power characteristics of the secondary battery.
  • Examples 9 to 20 by containing an additive with a symmetrical molecular structure in the electrolyte, gas production at high temperatures can be suppressed and the cycle characteristics of the secondary battery can be improved.
  • the lithium-ion battery At 45°C, first charge the lithium-ion battery to 4.2V with a constant current of 1C, further charge it with a constant voltage of 4.2V to a current of 0.05C, and then discharge the lithium-ion battery to 2.8V with a constant current of 1C, as a During the charge and discharge cycle, the discharge capacity this time is the discharge capacity of the lithium-ion battery after the first cycle.
  • the lithium-ion battery was subjected to 600 cycle charge/discharge tests according to the above method.
  • Capacity retention rate (%) of a lithium-ion battery after 600 cycles discharge capacity after 600 cycles/discharge capacity after the first cycle ⁇ 100%.

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Abstract

本申请涉及一种正极活性材料、二次电池和用电装置。所述正极活性材料包括：活性组分；以及包含有机组分的包覆层，其包覆于活性组分的至少部分表面，有机组分包括式(1)所示的化合物和/或经式(1)所示的化合物交联聚合形成的聚合物，式(1)中，M选自磷原子、硼原子或硫原子；R选自氧原子、C1-C20烷氧基、经取代或未经取代的C6-C25芳香酚基和经取代或未取代的C5-C25的杂芳香酚基中的一种或多种；n表示R基团的数量，n选自2或3。本申请能够使得正极活性材料的低阻抗化和高功率化。

Description

正极活性材料、二次电池、电池模块、电池包和用电装置
相关申请的交叉引用
本申请要求享有于2022年03月10日提交的名称为“正极活性材料、二次电池、电池模块、电池包和用电装置”发明专利申请202210240269.1的优先权，本申请还要求享有于2023年01月09日提交的名称为“正极活性材料、二次电池、电池模块、电池包和用电装置”发明专利申请202310024556.3的优先权。
技术领域
本申请涉及电池技术领域，更具体地，涉及正极活性材料、二次电池和用电装置。
背景技术
二次电池具有工作性能可靠，以及无污染、无记忆效应等优点，因而被广泛应用。例如，随着环境保护问题日益受到重视，新能源汽车日益普及，动力型二次电池的需求将呈现爆发式增长。然而，随着二次电池的应用范围越来越广泛，对二次电池的性能也提出了严峻挑战。
作为二次电池的正极活性材料，例如采用具有尖晶石结构、层状结构、或富锂锰基的过渡金属氧化物。在使用这些正极活性材料的情况下，期待正极活性材料的低阻抗化和高功率化。
发明内容
本申请提供一种正极活性材料、二次电池和用电装置，本申请能够使得正极活性材料的低阻抗化和高功率化。
第一方面，本申请提出了一种正极活性材料，所述正极活性材料包括：活性组分；以及包含有机组分的包覆层，其包覆于活性组分的至少部分表面，有机组分包括式(1)所示的化合物和/或经式(1)所示的化合物交联聚合形成的聚合物，
式(1)中，M选自磷原子、硼原子或硫原子；R选自氧原子、C1-C20烷氧基、经取代或未经取代的C6-C25芳香酚基和经取代或未取代的C5-C25的杂芳香酚基中的一种或多种；n表示R基团的数量，n选自2或3。
由此，本申请的包覆层包覆于活性材料的表面，包覆层中的M原子能够和活性材料中的氧原子相互作用，起到稳固氧原子的作用，保证活性组分的晶格稳定性，且氧原子不易从晶格中脱出与电解液发生副反应，从而使得正极活性材料整体的结构稳定性更好，以此改善二次电池的循环性能和容量性能；并且能够稳定正极活性材料和电解液之间的接触界面，正极活性材料表面所形成的正极固态电解质界面膜CEI膜的稳定性更好，使得动力学性能更好；M原子可能与电解液中的氟离子发生配位反应，从而能够有效抑制钝化物LiF生成，从而降低二次电池的直流阻抗，由此提升二次电池的功率性能。
在任意实施方式中，活性组分包括以下组分中的至少一种：LisTqNiaCobMncM(1- a-b-c)Yt，其中，0≤s≤2.1，0≤q≤2.1，且0.9≤s+q≤2.1；0≤a≤1，0≤b≤1，0≤c≤1，且0.1≤a+b+c≤1；1.8≤t≤3.5；T选自Na、K、Mg中的一种或几种；M选自B、Mg、Al、Si、P、S、Ca、Sc、Ti、V、Cr、Fe、Cu、Zn、Sr、Y、Zr、Nb、Mo、Cd、Sn、Sb、Te、Ba、Ta、W、Yb、La、Ce中的一种或几种；Y选自O、F中的一种或多种；xLi2MnO3·(1-x)LiMnyB1-yO2，其中，0.1≤x≤0.9，0.1≤y≤0.9，B选自Ni、Co、B、Mg、Al、Si、P、S、Ca、Sc、Ti、V、Cr、Fe、Cu、Zn、Sr、Y、Zr、Nb、Mo、Cd、Sn、Sb、Te、Ba、Ta、W、Yb、La、Ce中的一种或多种。
在任意实施方式中，M包括磷原子，式(1)所示的化合物包括式(I)和/或式(II)所示的化合物：
式(I)和式(II)中，R1、R2、R3和R4各自独立地选自氢原子、经取代或未取代的C1-C20烷基、经取代或未取代的C6-C25芳基、或者经取代或未取代的C5-C25的杂芳香基；可选地，R1、R2、R3和R4各自独立地选自C1-C3烷基、苯基、萘基、蒽基、菲基、二联苯基或三联苯基。由此，本申请的磷原子与活性组分中的氧相互作用，能够稳定正极界面，改善动力学，并且磷离子可与电解液中的氟离子配位，有效 抑制钝化物LiF生成，从而改善直流阻抗。由此，能够提高二次电池的功率特性和循环特性。
在任意实施方式中，式(I)所示的化合物包括式(P-11)至式(P-16)所示化合物中的一种或多种：
和/或
式(II)所示的化合物包括式(P-21)和/或式(P-22)所示化合物：
在任意实施方式中，M包括硼原子，式(1)所示的化合物包括式(III)所示的化合物：
式(III)中，R6和R7各自独立地选自氢原子、经取代或未取代的C1-C20烷基、经取代或未取代的C6-C25芳基、或者经取代或未取代的C5-C25的杂芳香基；可选地，R6和R7各自独立地选自C1-C3烷基、苯基、萘基、蒽基、菲基、二联苯基或三联苯基。硼原子与活性组分中的氧相互作用，能够稳定正极界面，改善动力学，并且硼离子可与电解液中的氟离子配位，有效抑制钝化物LiF生成，从而改善直流阻抗。由此，能够提高二次电池的功率特性和循环特性。
在任意实施方式中，式(III)所示的化合物包括式(B-1)至式(B-3)所示化 合物中的一种或多种：
在任意实施方式中，M包括硫原子，式(1)所示的化合物包括式(IV)所示的化合物：
式(IV)中，R5选自氢原子、经取代或未取代的C1-C20烷基、经取代或未取代的C6-C25芳基、或者经取代或未取代的C5-C25的杂芳香基；可选地，R5各自独立地选自C1-C3烷基、苯基、萘基、蒽基、菲基、二联苯基或三联苯基。硫原子与活性组分中的氧相互作用，能够稳定正极界面，改善动力学，并且硼离子可与电解液中的氟离子配位，有效抑制钝化物LiF生成，从而改善直流阻抗。由此，能够提高二次电池的功率特性和循环特性。
在任意实施方式中，式(IV)所示的化合物包括式(S-1)和/或式(S-2)所示化合物：
在任意实施方式中，包覆层包括经式(1)所示的化合物交联聚合形成的聚合物；聚合物的重均分子量为500Da至2000Da；可选为1000Da至1500Da；和/或包覆层的孔隙率为5％至20％。聚合物的重均分子量在上述范围时，聚合物所形成的包覆层的粘度相对较高，其与活性组分的结合力度相对较强，在二次电池长期循环过程中，包覆层不易从活性组分的表面脱落，从而能够对活性组分起到长期稳定的防护作用，保证二次电池的循环性能和容量性能等。并且聚合物所形成的包覆层的粘度不会过高，其所形成的包覆层更易控制，包覆层厚度更均匀，对活性组分的防护性能均一。由于式(1)所示的化合物通过交联形成聚合物，聚合物可能具有孔结构，由此使得聚合物所形成的包覆层具有一定的孔隙，该孔隙的存在有利于活性离子的脱出或嵌入， 降低直流阻抗，改善动力学性能。
在任意实施方式中，基于正极活性材料的总质量计，有机组分在正极活性材料中的质量含量记为A％，0.1≤A≤0.5；可选地，0.2≤A≤0.4；和/或包覆层的厚度为5μm至20μm；可选为5μm至10μm。有机组分的含量在上述范围内，一方面能够使得有机组分起到对活性组分充分的防护作用，改善二次电池的循环性能和容量性能；另一方面使得有机组分所形成的包覆层的厚度不会过厚，改善动力学性能，由此，能够进一步提高二次电池的功率特性和循环特性。
本申请第二方面提供了一种二次电池，所述二次电池包括：正极极片、负极极片、设置于正极极片和负极极片之间的隔离膜以及电解液，正极极片包括如本申请第一方面任一实施方式所述的正极活性材料。
在任意实施方式中，电解液包括第一添加剂，第一添加剂被配置为在正极活性材料表面成膜，其中，第一添加剂包括具有硫、磷、硼中至少一种杂环元素的含氧杂环化合物，且含氧杂环化合物包括以碳碳单键对称的镜像结构。由此，本申请的第一添加剂为具有对称结构的特异性分子，这些分子首先可以优先于电解液的溶剂在正极活性材料表面被氧化成膜，其次这些分子也会物理吸附在正极活性材料表面，由于其结构的对称性，其吸附成膜的均匀性和一致性好，可以改善正极活性材料的高温存储产气等问题，并进一步提高循环特性。并且，由于正极活性材料的表面为包覆层，包覆层有利于第一添加剂的吸附，进一步提高第一添加剂的成膜效果。可选地，第一添加剂还可以在负极活性材料表面成膜，同样可以改善在负极活性材料表面的成膜性能，由此进一步提高二次电池的循环特性。
在任意实施方式中，第一添加剂包括式(2)至式(5)所示化合物中的一种或多种：
在任意实施方式中，基于正极活性材料的总质量计，有机组分在正极活性材料中的质量含量记为A％；基于电解液的总质量计，第一添加剂在电解液中的质量含量记为B％，其中，二次电池满足：0.5≤B/A≤2。由此，本申请的电解液中的第一添加剂和正极活性材料中的有机组分相互配合，有利于在正极活性材料表面形成均匀且致密的CEI膜，对正极活性材料中的活性组分起到优异的防护作用，保证活性组分的结构稳定性，改善二次电池的循环性能和容量性能；并且CEI膜的厚度不会过厚，有利于活性离子的脱出或嵌入，从而能够降低二次电池的直流阻抗，改善二次电池的功率特 性。
在任意实施方式中，基于电解液的总质量计，第一添加剂在电解液中的质量含量记为B％，0.10≤B≤0.70。
在任意实施方式中，第一添加剂包括式(2)所示化合物至式(5)所示化合物中的至少两种；基于第一添加剂的总摩尔量记，第一添加剂中的其中一种化合物的摩尔含量，与其中另一种化合物的摩尔含量的比值记为C，1≤C≤2；可选地，1.2≤C≤1.5。由此，本申请通过两种上化合物的相互配合，能够使得第一添加剂在正极活性材料表面所形成的CEI膜的组分更丰富，CEI膜的结构更稳定，且有利于活性离子的嵌入或脱出，由此改善二次电池的循环性能。并且第一添加剂可能在负极活性材料表面也能够形成组分丰富的SEI膜，由此进一步改善二次电池的循环性能。
本申请提出了一种用电装置，包括如本申请第二方面任一实施方式的所述的二次电池。
附图说明
图1是本申请一实施方式的二次电池的示意图。
图2是图1所示的本申请一实施方式的二次电池的分解图。
图3是本申请一实施方式的电池模块的示意图。
图4是本申请一实施方式的电池包的示意图。
图5是图4所示的本申请一实施方式的电池包的分解图。
图6是本申请一实施方式的二次电池用作电源的用电装置的示意图。
附图标记说明：
1、电池包；2、上箱体；3、下箱体；4、电池模块；5、二次电池；51、壳体；52、电极组件；53、顶盖组件。
具体实施方式
以下，适当地参照附图详细说明具体公开了本申请的正极活性材料、二次电池和用电装置的实施方式。但是会有省略不必要的详细说明的情况。例如，有省略对已众所周知的事项的详细说明、实际相同结构的重复说明的情况。这是为了避免以下的说明不必要地变得冗长，便于本领域技术人员的理解。此外，附图及以下说明是为了本领域技术人员充分理解本申请而提供的，并不旨在限定权利要求书所记载的主题。
本申请所公开的“范围”以下限和上限的形式来限定，给定范围是通过选定一个下限和一个上限进行限定的，选定的下限和上限限定了特别范围的边界。这种方式进行限定的范围可以是包括端值或不包括端值的，并且可以进行任意地组合，即任何下限可以与任何上限组合形成一个范围。例如，如果针对特定参数列出了60-120和80-110的范围，理解为60-110和80-120的范围也是预料到的。此外，如果列出的最小范围值1和2，和如果列出了最大范围值3，4和5，则下面的范围可全部预料到：1-3、 1-4、1-5、2-3、2-4和2-5。在本申请中，除非有其他说明，数值范围“a-b”表示a到b之间的任意实数组合的缩略表示，其中a和b都是实数。例如数值范围“0-5”表示本文中已经全部列出了“0-5”之间的全部实数，“0-5”只是这些数值组合的缩略表示。另外，当表述某个参数为≥2的整数，则相当于公开了该参数为例如整数2、3、4、5、6、7、8、9、10、11、12等。
如果没有特别的说明，本申请的所有实施方式以及可选实施方式可以相互组合形成新的技术方案。
如果没有特别的说明，本申请的所有技术特征以及可选技术特征可以相互组合形成新的技术方案。
如果没有特别的说明，本申请的所有步骤可以顺序进行，也可以随机进行，优选是顺序进行的。例如，所述方法包括步骤(a)和(b)，表示所述方法可包括顺序进行的步骤(a)和(b)，也可以包括顺序进行的步骤(b)和(a)。例如，所述提到所述方法还可包括步骤(c)，表示步骤(c)可以任意顺序加入到所述方法，例如，所述方法可以包括步骤(a)、(b)和(c)，也可包括步骤(a)、(c)和(b)，也可以包括步骤(c)、(a)和(b)等。
如果没有特别的说明，本申请所提到的“包括”和“包含”表示开放式，也可以是封闭式。例如，所述“包括”和“包含”可以表示还可以包括或包含没有列出的其他组分，也可以仅包括或包含列出的组分。
如果没有特别的说明，在本申请中，术语“或”是包括性的。举例来说，短语“A或B”表示“A，B，或A和B两者”。更具体地，以下任一条件均满足条件“A或B”：A为真(或存在)并且B为假(或不存在)；A为假(或不存在)而B为真(或存在)；或A和B都为真(或存在)。
术语“烷氧基”是指烷基与氧原子以单键连接的基团。例如烷氧基可以为C1-C20烷氧基、C1-C15烷氧基、C1-C10烷氧基、C1-C8烷氧基、C1-C5烷氧基、C2-C6烷氧基。在一些实施例中，烷氧基可以包括甲氧基、乙氧基、丙氧基、丁氧基、异丁氧基、仲丁氧基、叔丁氧基、环丁氧基、戊氧基、异戊氧基、新戊氧基、叔戊氧基、环戊氧基。
术语“芳基”是指闭合的芳族环或环体系。例如芳基可以为C6-C50芳基、C6-C40芳基、C6-C30芳基、C6-C20芳基、C6-C10芳基，其中C6-C30芳基是指含有6-30个用于形成环的碳原子。在一些实施例中，芳基包括苯基、萘基、菲基、蒽基、联苯基、三亚苯基、芘基、螺双芴基、苝基、茚基和薁基等。
术语“芳杂环基”是指芳基中的环中碳原子被杂原子所取代，杂原子可以包括氮原子、氧原子、硫原子等。
术语“芳香酚基”是指芳基的方族环中的碳原子与羟基结合所形成的基团。例如芳香酚基可以为C6-C25芳香酚基、C6-C20芳香酚基、C6-C15芳香酚基、C6-C10芳香酚基。在一些实施例中，芳香酚基可以包括苯羟基、萘羟基、菲羟基、蒽羟基、联苯羟基、三亚苯羟基、芘羟基、螺双芴羟基、苝羟基、茚羟基和薁羟基等。
术语“杂芳香酚基”是指方族环中碳原子被杂原子所取代，杂原子可以包括氮原子、氧原子、硫原子等。在一些实施例中，杂芳香酚基可以包括杂氮苯羟基、杂氮萘 羟基、杂氮菲羟基、杂氮蒽羟基、杂氮联苯羟基、杂氮三亚苯羟基、杂氮芘羟基、杂氮螺双芴羟基、杂氮苝羟基、杂氮茚羟基、杂氮薁羟基、杂硫苯羟基、杂硫萘羟基、杂硫菲羟基、杂硫蒽羟基、杂硫联苯羟基、杂氧苯羟基、杂氧萘羟基、杂氧菲羟基、杂氧蒽羟基、杂氧联苯羟基等。
上述基团经取代时，其取代基可以为卤素原子等。
正极活性材料作为提供活性离子和嵌入活性离子的一方，其材料结构的稳定性对二次电池的性能具有直接影响。在二次电池充放电循环过程中，氧原子容易从晶格位置脱出，导致晶格结构不稳定性；并且脱出的氧原子由于具有较高的反应活性，能够和正极活性材料表面的电解液发生副反应，导致正极活性材料表面的界面膜不稳定。再者，正极活性材料自身结构稳定性可能较差，尤其是在高温高压体系下容易发生分解释放大量的氧气，进一步恶化正极活性材料的性能。采用该类正极活性材料的二次电池的循环性能较差、容量衰减过快。
鉴于此，本申请从防护正极活性材料的角度出发，在正极活性材料的表面包覆有包覆层，以稳定正极活性材料的结构，提高正极活性材料的循环性能，并改善采用所述正极活性材料的二次电池的循环性能和容量性能，并能够同时改善其功率性能，接下来对本申请进行详细说明。
正极活性材料
第一方面，本申请提出了一种正极活性材料，所述正极活性材料包括活性组分和包覆层；包覆层包覆于有活性组分的至少部分表面，能够对活性组分起到优异的防护作用。包覆层中包含有机组分，有机组分包括式(1)所示的化合物和/或经式(1)所示的化合物交联聚合形成的聚合物，
式(1)中，
M选自磷原子、硼原子或硫原子；
R选自氧原子、C1-C20烷氧基、经取代或未经取代的C6-C25芳香酚基和经取代或未取代的C5-C25的杂芳香酚基中的一种或多种；
n表示R基团的数量，n选自2或3；n的取值取决于M所取原子的种类。
虽然机理尚不明确，但本申请通过上述有机组分包覆上述活性组分，能够显著改善正极活性材料的结构稳定性，在正极活性材料应用于二次电池时，能够改善二次电池的循环性能和容量性能，并能够改善其功率特性。
本申请的发明人推测本申请的作用机理可能如下：
活性组分中通常包含氧原子。包覆层包覆于活性材料的表面，包覆层中的M原子能够和活性材料中的氧原子相互作用，起到稳固氧原子的作用，保证活性组分的晶格稳定性，且氧原子不易从晶格中脱出与电解液发生副反应，从而使得正极活性材料整体的结构稳定性更好，以此改善二次电池的循环性能和容量性能；并且能够稳定正极活性材料和电解液之间的接触界面，正极活性材料表面所形成的正极固态电解质界面膜CEI膜的稳定性更好，使得动力学性能更好；M原子可能与电解液中的氟离子发生配位反应，从而能够有效抑制钝化物LiF生成，从而降低二次电池的直流阻抗，由此提升二次电池的功率性能。
在一些实施方式中，活性组分能够为二次电池提供容量，可以包括以下材料中的至少一种：层状结构正极活性材料(例如三元、镍酸锂/钠、钴酸锂/钠、锰酸锂/钠、富锂/钠层状和岩盐相层状等材料)、尖晶石结构的正极活性材料(例如尖晶石锰酸锂、尖晶石镍锰酸锂、富锂的尖晶石锰酸锂和镍锰酸锂等)、橄榄石型磷酸盐活性材料。可选为层状结构和/或尖晶石结构的正极活性材料。
示例性地，层状结构正极活性材料的通式为：LisTqNiaCobMncM(1-a-b-c)Yt，其中，0≤s≤2.1，0≤q≤2.1，且0.9≤s+q≤2.1；0≤a≤1，0≤b≤1，0≤c≤1，且0.1≤a+b+c≤1；1.8≤t≤3.5；T选自Na、K、Mg中的一种或几种；M选自B、Mg、Al、Si、P、S、Ca、Sc、Ti、V、Cr、Fe、Cu、Zn、Sr、Y、Zr、Nb、Mo、Cd、Sn、Sb、Te、Ba、Ta、W、Yb、La、Ce中的一种或几种；Y选自O、F中的一种或几种。可选地，a+b+c＝1，q＝0，t＝2，s＝1，即层状结构正极活性材料的通式为：LiNiaCobMncY2。具体地，层状结构正极活性材料可以包括钴酸锂LCO、镍酸锂LNO、锰酸锂LMO、LiNi1/3Co1/3Mn1/3O2(NCM333)、LiNi0.8Co0.1Mn0.1O2(NCM811)和LiNi0.5Co0.2Mn0.3O2(NCM523)中的一种或多种。
示例性地，尖晶石结构的正极活性材料的通式为：xLi2MnO3·(1-x)LiMnyB1- yO2，其中，0.1≤x≤0.9，0.1≤y≤0.9，B选自Ni、Co、B、Mg、Al、Si、P、S、Ca、Sc、Ti、V、Cr、Fe、Cu、Zn、Sr、Y、Zr、Nb、Mo、Cd、Sn、Sb、Te、Ba、Ta、W、Yb、La、Ce中的一种或几种；可选地，B选自Na、K、Mg中的一种或几种。具体地，尖晶石结构的正极活性材料包括LiMn2O4、LiNi0.5Mn1.5O4、LiCr0.3Mn1.7O4、Li1.1Al0.1Mn1.9O4、Li2Mn2O4和Li1.5Mn2O4中的一种或多种。
示例性地，橄榄石型磷酸盐活性材料的通式为：LixAyMeaMbP1-cXcYz，其中，0≤x≤1.3，0≤y≤1.3，且0.9≤x+y≤1.3；0.9≤a≤1.5，0≤b≤0.5，且0.9≤a+b≤1.5；0≤c≤0.5；3≤z≤5；A选自Na、K、Mg中的一种或几种；Me选自Mn、Fe、Co、Ni中的一种或几种；M选自B、Mg、Al、Si、P、S、Ca、Sc、Ti、V、Cr、Cu、Zn、Sr、Y、Zr、Nb、Mo、Cd、Sn、Sb、Te、Ba、Ta、W、Yb、La、Ce中的一种或几种；X选自S、Si、Cl、B、C、N中的一种或几种；Y选自O、F中的一种或几种。具体地，橄榄石型磷酸盐活性材料包括LiFePO4、LiMnPO4、LiNiPO4、和LiCoPO4中的一种或多种。
包覆层包覆于活性组分的表面，可以是将活性组分的全部表面进行包覆，如此能够对活性组分进行充分的防护；也可以是将活性组分的部分表面进行包覆，如此能够在对活性组分进行防护的基础上，保证二次电池的直流阻抗相对较低，有利于兼顾 二次电池的循环性能和功率特性。包覆层包括有机组分，有机组分可以是小分子的单体结构，也可以是单体结构之间发生相互交联所形成的大分子聚合物。小分子的单体结构更容易调控其成膜的厚度；大分子聚合物所形成的膜层更为均匀致密，对活性组分的防护力度更好。
在一些实施方式中，R选自氧原子、C1-C10烷氧基、经取代或未经取代的C6-C10芳香酚基和经取代或未取代的C5-C10的杂芳香酚基中的一种或多种。可选地，R选自C1-C3烷基、苯基、萘基、蒽基、菲基、二联苯基或三联苯基。
在一些实施方式中，M包括磷原子。磷原子与活性组分中的氧相互作用，能够稳定正极界面，改善动力学，并且磷离子可与电解液中的氟离子配位，有效抑制钝化物LiF生成，从而改善直流阻抗。由此，能够提高二次电池的功率特性和循环特性。
作为一些示例，所述式(1)所示的化合物包括式(I)所示的化合物：
式(I)中，R1和R2、R3和R4各自独立地选自氢原子、经取代或未取代的C1-C20烷基、经取代或未取代的C6-C25芳基、或者经取代或未取代的C5-C25的杂芳香基；
可选地，R1和R2、R3和R4各自独立地选自C1-C3烷基、苯基、萘基、蒽基、菲基、二联苯基或三联苯基。
示例性地，所述式(I)所示的化合物包括式(P-11)至式(P-16)所示化合物中的一种或多种：
作为另一些示例，所述式(1)所示的化合物包括式(II)所示的化合物：
式(II)中，R3和R4各自独立地选自氢原子、经取代或未取代的C1-C20烷基、经取代或未取代的C6-C25芳基、或者经取代或未取代的C5-C25的杂芳香基；可选地，R3和R4各自独立地选自C1-C3烷基、苯基、萘基、蒽基、菲基、二联苯基或三联苯基。
示例性地，所述式(I)所示的化合物包括式(P-21)和式(P-22)所示化合物中的一种或多种：
作为再一些示例，所述式(1)所示的化合物包括式(I)所示的化合物和式(II)所示的化合物。
在一些实施方式中，M包括硼原子。硼原子与活性组分中的氧相互作用，能够稳定正极界面，改善动力学，并且硼离子可与电解液中的氟离子配位，有效抑制钝化物LiF生成，从而改善直流阻抗。由此，能够提高二次电池的功率特性和循环特性。
作为一些示例，所述式(1)所示的化合物包括式(III)所示的化合物：
式(III)中，R6和R7各自独立地选自氢原子、经取代或未取代的C1-C20烷基、经取代或未取代的C6-C25芳基、或者经取代或未取代的C5-C25的杂芳香基；可选地，R6和R7各自独立地选自C1-C3烷基、苯基、萘基、蒽基、菲基、二联苯基或三联苯基。
示例性地，所述式(III)所示的化合物包括式(B-1)至式(B-3)所示化合物中的一种或多种：

在一些实施方式中，M包括硫原子。硫原子与活性组分中的氧相互作用，能够稳定正极界面，改善动力学，并且硼离子可与电解液中的氟离子配位，有效抑制钝化物LiF生成，从而改善直流阻抗。由此，能够提高二次电池的功率特性和循环特性。
作为一些示例，所述式(1)所示的化合物包括式(IV)所示的化合物：
式(IV)中，R5选自氢原子、经取代或未取代的C1-C20烷基、经取代或未取代的C6-C25芳基、或者经取代或未取代的C5-C25的杂芳香基；
可选地，R5各自独立地选自C1-C3烷基、苯基、萘基、蒽基、菲基、二联苯基或三联苯基。
示例性地，所述式(IV)所示的化合物包括式(S-1)和/或式(S-2)所示化合物：
本申请的发明人发现，当正极活性材料满足以下条件中的一个或多个时，能够进一步改善二次电池的循环性能、容量性能和功率性能。
在一些实施方式中，所述聚合物的重均分子量为500Da至2000Da。
聚合物的重均分子量在上述范围时，聚合物所形成的包覆层的粘度相对较高，其与活性组分的结合力度相对较强，在二次电池长期循环过程中，包覆层不易从活性组分的表面脱落，从而能够对活性组分起到长期稳定的防护作用，保证二次电池的循环性能和容量性能等。并且聚合物所形成的包覆层的粘度不会过高，其所形成的包覆层更易控制，包覆层厚度更均匀，对活性组分的防护性能均一。可选地，聚合物的重均分子量为1000Da至1500Da。聚合物的重均分子量为500Da、600Da、800Da、900Da、1000Da、1200Da、1500Da、1800Da、2000Da或是上述任意两个数值组成的范围。
在一些实施方式中，所述包覆层的孔隙率为5％至20％。
由于式(1)所示的化合物通过交联形成聚合物，聚合物可能具有孔结构，由此使得聚合物所形成的包覆层具有一定的孔隙，该孔隙的存在有利于活性离子的脱出 或嵌入，降低直流阻抗，改善动力学性能。示例性地，包覆层的孔隙率可以为5％、6％、8％、10％、12％、15％、16％、18％、19％、20％或是上述任意两个数值组成的范围。
在本申请中，孔隙率是指包覆层内孔体积占据包覆层总体积的比率。孔隙率可以按照GB/T24586，采用气体置换法测量。孔隙率W＝(L1-L2)/L1*100％，其中L1是样品的表观体积，L2是样品的真实体积。)
在一些实施方式中，基于所述正极活性材料的总质量计，所述有机组分在所述正极活性材料中的质量含量记为A％，0.1≤A≤0.5；可选地0.2≤A≤0.4。
有机组分的含量在上述范围内，一方面能够使得有机组分起到对活性组分充分的防护作用，改善二次电池的循环性能和容量性能；另一方面使得有机组分所形成的包覆层的厚度不会过厚，改善动力学性能，由此，能够进一步提高二次电池的功率特性和循环特性。示例性地，有机组分在所述正极活性材料中的质量含量记为A％可以为0.1％、0.2％、0.3％、0.4％、0.5％或是上述任意两个数值组成的范围。
在一些实施方式中，所述包覆层的厚度为5μm至20μm；可选为5μm至10μm。
包覆层的厚度在上述范围内，一方面能够使得有机组分起到对活性组分充分的防护作用，改善二次电池的循环性能和容量性能；另一方面使得有机组分所形成的包覆层的厚度不会过厚，改善动力学性能，由此，能够进一步提高二次电池的功率特性和循环特性。示例性地，包覆层的厚度可以为5μm、6μm、8μm、10μm、12μm、15μm、16μm、18μm、20μm或是上述任意两个数值组成的范围。
二次电池
第二方面，本申请提供了一种二次电池，所述二次电池包括正极极片、负极极片、设置于所述正极极片和所述负极极片之间的隔离膜以及电解液，所述正极极片包括正极膜层，正极膜层包括如本申请第一方面任一实施方式所述的正极活性材料。正极活性材料中的活性组分通过有机组分的包覆，能够显著改善二次电池的循环性能、容量性能和功率性能。
在一些实施方式中，正极极片包括正极集流体以及设置在正极集流体至少一个表面上的正极膜层。例如，正极集流体具有在自身厚度方向相对的两个表面，正极膜层设置于正极集流体的两个相对表面中的任意一者或两者上。
在一些实施方式中，正极膜层还可选地包括正极导电剂。本申请对正极导电剂的种类没有特别的限制，作为示例，正极导电剂包括选自超导碳、导电石墨、乙炔黑、炭黑、科琴黑、碳点、碳纳米管、石墨烯和碳纳米纤维中的一种或多种的组合。在一些实施方式中，基于正极膜层的总质量，正极导电剂的质量百分含量在5％以下。
在一些实施方式中，正极膜层还可选地包括正极粘结剂。本申请对正极粘结剂的种类没有特别的限制，作为示例，正极粘结剂可包括选自聚偏氟乙烯(PVDF)、聚四氟乙烯(PTFE)、偏氟乙烯-四氟乙烯-丙烯三元共聚物、偏氟乙烯-六氟丙烯-四氟乙烯三元共聚物、四氟乙烯-六氟丙烯共聚物和含氟丙烯酸酯类树脂中的 一种或多种的组合。在一些实施方式中，基于正极膜层的总质量，正极粘结剂的质量百分含量在5％以下。
在一些实施方式中，正极集流体可采用金属箔片或复合集流体。作为金属箔片的示例，可采用铝箔或铝合金箔。复合集流体可包括高分子材料基层以及形成于高分子材料基层至少一个表面上的金属材料层，作为示例，金属材料可包括选自铝、铝合金、镍、镍合金、钛、钛合金、银和银合金中的一种或多种的组合，高分子材料基层可包括选自聚丙烯(PP)、聚对苯二甲酸乙二醇酯(PET)、聚对苯二甲酸丁二醇酯(PBT)、聚苯乙烯(PS)和聚乙烯(PE)中的一种或多种的组合。
正极膜层通常是将正极浆料涂布在正极集流体上，经干燥、冷压而成的。正极浆料通常是将正极活性材料、可选的导电剂、可选的粘结剂以及任意的其他组分分散于溶剂中并搅拌均匀而形成的。溶剂可以是N-甲基吡咯烷酮(NMP)，但不限于此。
[负极极片]
负极极片包括负极集流体以及设置在负极集流体至少一个表面上的负极膜层，所述负极膜层包括负极活性材料。
作为示例，负极集流体具有在其自身厚度方向相对的两个表面，负极膜层设置在负极集流体相对的两个表面中的任意一者或两者上。
在一些实施方式中，所述负极集流体可采用金属箔片或复合集流体。例如，作为金属箔片，可以采用铜箔。复合集流体可包括高分子材料基层和形成于高分子材料基材至少一个表面上的金属层。复合集流体可通过将金属材料(铜、铜合金、镍、镍合金、钛、钛合金、银及银合金等)形成在高分子材料基材(如聚丙烯(PP)、聚对苯二甲酸乙二醇酯(PET)、聚对苯二甲酸丁二醇酯(PBT)、聚苯乙烯(PS)、聚乙烯(PE)等的基材)上而形成。
在一些实施方式中，负极活性材料可采用本领域公知的用于电池的负极活性材料。作为示例，负极活性材料可包括以下材料中的至少一种：人造石墨、天然石墨、软炭、硬炭、硅基材料、锡基材料和钛酸锂等。所述硅基材料可选自单质硅、硅氧化合物、硅碳复合物、硅氮复合物以及硅合金中的至少一种。所述锡基材料可选自单质锡、锡氧化合物以及锡合金中的至少一种。但本申请并不限定于这些材料，还可以使用其他可被用作电池负极活性材料的传统材料。这些负极活性材料可以仅单独使用一种，也可以将两种以上组合使用。
在一些实施方式中，负极膜层还可选地包括负极粘结剂。所述负极粘结剂可选自丁苯橡胶(SBR)、聚丙烯酸(PAA)、聚丙烯酸钠(PAAS)、聚丙烯酰胺(PAM)、聚乙烯醇(PVA)、海藻酸钠(SA)、聚甲基丙烯酸(PMAA)及羧甲基壳聚糖(CMCS)中的至少一种。
在一些实施方式中，负极膜层还可选地包括导电剂。导电剂可选自超导碳、乙炔黑、炭黑、科琴黑、碳点、碳纳米管、石墨烯及碳纳米纤维中的至少一种。
在一些实施方式中，负极膜层还可选地包括其他助剂，例如增稠剂(如羧甲基纤维素钠(CMC-Na))等。
在一些实施方式中，可以通过以下方式制备负极极片：将上述用于制备负极极片的组分，例如负极活性材料、导电剂、粘结剂和任意其他组分分散于溶剂(例如去离子水)中，形成负极浆料；将负极浆料涂覆在负极集流体上，经烘干、冷压等工序后，即可得到负极极片。
[电解质]
电解质在正极极片和负极极片之间起到传导离子的作用。本申请对电解质的种类没有具体的限制，可根据需求进行选择。例如，电解质可以是液态的、凝胶态的或全固态的。
在一些实施方式中，所述电解质采用电解液。所述电解液包括电解质盐和溶剂。
在一些实施方式中，所述电解质采用电解液。所述电解液包括电解质盐和溶剂。
作为示例，锂盐可包括选自六氟磷酸锂(LiPF6)、四氟硼酸锂(LiBF4)、高氯酸锂(LiClO4)、六氟砷酸锂(LiAsF6)、双氟磺酰亚胺锂(LiFSI)、双三氟甲磺酰亚胺锂(LiTFSI)、三氟甲磺酸锂(LiTFS)、二氟草酸硼酸锂(LiDFOB)、二草酸硼酸锂(LiBOB)、二氟磷酸锂(LiPO2F2)、二氟二草酸磷酸锂(LiDFOP)和四氟草酸磷酸锂(LiTFOP)中的一种或多种的组合。
作为示例，有机溶剂可包括选自碳酸乙烯酯(EC)、碳酸亚丙酯(PC)、碳酸甲乙酯(EMC)、碳酸二乙酯(DEC)、碳酸二甲酯(DMC)、碳酸二丙酯(DPC)、碳酸甲丙酯(MPC)、碳酸乙丙酯(EPC)、碳酸亚丁酯(BC)、甲酸甲酯(MF)、乙酸甲酯(MA)、乙酸乙酯(EA)、乙酸丙酯(PA)、丙酸甲酯(MP)、丙酸乙酯(EP)、丙酸丙酯(PP)、丁酸甲酯(MB)、丁酸乙酯(EB)、1,4-丁内酯(GBL)、环丁砜(SF)、二甲砜(MSM)、甲乙砜(EMS)和二乙砜(ESE)中的一种或多种的组合。
在一些实施方式中，所述电解液还可选地包括添加剂。例如添加剂可以包括负极成膜添加剂、正极成膜添加剂，还可以包括能够改善电池某些性能的添加剂，例如改善电池过充性能的添加剂、改善电池高温或低温性能的添加剂等。
虽然机理不甚明确，但是发明人发现当电解液中添加特定的添加剂例如第一添加剂时，能够显著改善成膜性能，由此改善二次电池的循环性能等。该第一添加剂的属性如下：第一添加剂被配置为在正极活性材料的表面成膜，其中，所述第一添加剂包括具有硫、磷、硼中至少一种杂环元素的含氧杂环化合物，且所述含氧杂环化合物包括以碳碳单键对称的镜像结构。该第一添加剂为具有对称结构的特异性分子，这些分子首先可以优先于电解液的溶剂在正极活性材料表面被氧化成膜，其次这些分子也会物理吸附在正极活性材料表面，由于其结构的对称性，其吸附成膜的均匀性和一致性好，可以改善正极活性材料的高温存储产气等问题，并进一步提高循环特性。并且，由于正极活性材料的表面为包覆层，包覆层有利于第一添加剂的吸附，进一步提高第一添加剂的成膜效果。可选地，第一添加剂还可以在负极活性材料表面成膜， 同样可以改善在负极活性材料表面的成膜性能，由此进一步提高二次电池的循环特性。
在一些实施方式中，第一添加剂包括硫元素；具体地，第一添加剂包括式(2)至式(5)所示化合物中的一种或多种：
上述添加剂为包含硫原子且具有对称结构的特异性分子，这些分子可以优先于溶剂在材料表面被氧化成膜，其次这些分子也会物理吸附在正极活性材料表面，由于其结构的对称性，其吸附成膜的均匀性和一致性好，可以改善正极活性材料高温存储产气的问题，并进一步提高循环特性。
在一些实施方式中，第一添加剂包括式(2)所示化合物至式(5)所示化合物中的至少两种；基于所述第一添加剂的总摩尔量记，所述第一添加剂中的其中一种化合物的摩尔含量，与其中另一种化合物的摩尔含量的比值记为C，1≤C≤2；可选地，1.2≤C≤1.5。
通过两种上化合物的相互配合，能够使得第一添加剂在正极活性材料表面所形成的CEI膜的组分更丰富，CEI膜的结构更稳定，且有利于活性离子的嵌入或脱出，由此改善二次电池的循环性能。并且第一添加剂可能在负极活性材料表面也能够形成组分丰富的SEI膜，由此进一步改善二次电池的循环性能。
在一些实施方式中，上述包含磷的添加剂，其具体结构式类似于式(2)至式(5)，其不同之处在于，将式(2)至式(5)中的硫元素替换为磷元素，具体地，其结构式可以如式(6)所示：
在一些实施方式中，上述包含硼的添加剂，其具体结构式类似于式(2)至式(5)，其不同之处在于，将式(2)至式(5)中的硫元素替换为硼元素，具体地，其结构式可以如式(7)所示：
在一些实施方式中，基于电解液的总质量计，第一添加剂在电解液中的质量含量记为B％，其中，所述二次电池满足：0.5≤B/A≤2。
电解液中的第一添加剂和正极活性材料中的有机组分相互配合，有利于在正极活性材料表面形成均匀且致密的CEI膜，对正极活性材料中的活性组分起到优异的防护作用，保证活性组分的结构稳定性，改善二次电池的循环性能和容量性能；并且CEI膜的厚度不会过厚，有利于活性离子的脱出或嵌入，从而能够降低二次电池的直流阻抗，改善二次电池的功率特性。
示例性地，基于所述电解液的总质量计，所述第一添加剂在所述电解液中的质量含量记为B％，0.10≤B≤0.70。
[隔离膜]
在一些实施方式中，二次电池中还包括隔离膜。本申请对隔离膜的种类没有特别的限制，可以选用任意公知的具有良好的化学稳定性和机械稳定性的多孔结构隔离膜。
在一些实施方式中，隔离膜的材质可选自玻璃纤维、无纺布、聚乙烯、聚丙烯及聚偏二氟乙烯中的至少一种。隔离膜可以是单层薄膜，也可以是多层复合薄膜，没有特别限制。在隔离膜为多层复合薄膜时，各层的材料可以相同或不同，没有特别限制。
在一些实施方式中，正极极片、负极极片和隔离膜可通过卷绕工艺或叠片工艺制成电极组件。
本申请对二次电池的形状没有特别的限制，其可以是圆柱形、方形或其他任意的形状。如图1是作为一个示例的方形结构的二次电池5。
在一些实施例中，如图1和图2所示，外包装可包括壳体51和盖板53。其中，壳体51可包括底板和连接于底板上的侧板，底板和侧板围合形成容纳腔。壳体51具有与容纳腔连通的开口，盖板53用于盖设开口，以封闭容纳腔。正极极片、负极极片和隔离膜可经卷绕工艺或叠片工艺形成电极组件52。电极组件52封装于容纳腔。电解液浸润于电极组件52中。二次电池5所含电极组件52的数量可以为一个或多个，可根据需求来调节。
本申请的二次电池的制备方法是公知的。在一些实施例中，可将正极极片、隔离膜、负极极片和电解液组装形成二次电池。作为示例，可将正极极片、隔离膜、负极极片经卷绕工艺或叠片工艺形成电极组件，将电极组件置于外包装中，烘干后注入电解液，经过真空封装、静置、化成、整形等工序，得到二次电池。
在本申请的一些实施例中，根据本申请的二次电池可以组装成电池模块，电池模块所含二次电池的数量可以为多个，具体数量可根据电池模块的应用和容量来调节。
图3是作为一个示例的电池模块4的示意图。如图3所示，在电池模块4中，多个二次电池5可以是沿电池模块4的长度方向依次排列设置。当然，也可以按照其他任意的方式进行排布。进一步可以通过紧固件将该多个二次电池5进行固定。
可选地，电池模块4还可以包括具有容纳空间的外壳，多个二次电池5容纳于该容纳空间。
在一些实施例中，上述电池模块还可以组装成电池包，电池包所含电池模块的数量可以根据电池包的应用和容量进行调节。
图4和图5是作为一个示例的电池包1的示意图。如图4和图5所示，在电池包1中可以包括电池箱和设置于电池箱中的多个电池模块4。电池箱包括上箱体2和下箱体3，上箱体2用于盖设下箱体3，并形成用于容纳电池模块4的封闭空间。多个电池模块4可以按照任意的方式排布于电池箱中。
用电装置
第三方面，本申请提供一种用电装置，用电装置包括本申请的二次电池、电池模块和电池包中的至少一种。二次电池、电池模块和电池包可以用作用电装置的电源，也可以用作用电装置的能量存储单元。用电装置可以但不限于是移动设备(例如手机、笔记本电脑等)、电动车辆(例如纯电动车、混合动力电动车、插电式混合动力电动车、电动自行车、电动踏板车、电动高尔夫球车、电动卡车等)、电气列车、船舶及卫星、储能系统等。
用电装置可以根据其使用需求来选择二次电池、电池模块或电池包。
图6是作为一个示例的用电装置的示意图。该用电装置6为纯电动车、混合动力电动车、或插电式混合动力电动车等。为了满足该用电装置对高功率和高能量密度的需求，可以采用电池包1或电池模块。
作为另一个示例的用电装置可以是手机、平板电脑、笔记本电脑等。该用电装置通常要求轻薄化，可以采用二次电池作为电源。
实施例
以下，说明本申请的实施方式。下面描述的实施方式是示例性的，仅用于解释本申请，而不能理解为对本申请的限制。实施方式中未注明具体技术或条件的，按照本领域内的文献所描述的技术或条件或者按照产品说明书进行。所用试剂或仪器未注明生产厂商者，均为可以通过市购获得的常规产品。
实施例1
(1)正极活性材料的制备
将如表1的实施例1所示的有机组分溶解到乙酸乙酯溶剂中，配置10％浓度的有机溶液，将活性组分(LiNi0.8Co0.1Mn0.1O2)加入上述溶液中，以1：10的质量比混合，在40℃至50℃环境下中搅拌分散4h，加入若干FeCl3引发剂，进一步引发有机组分交联包覆，继续搅拌4h后，过滤除去溶剂，随后在80℃真空烘箱中烘干8h，得到具有有机组分包覆的活性组分，即正极活性材料。
(2)正极极片的制备：
采用厚度为12μm的铝箔作为正极集流体。
将上述(1)中制得的正极活性材料、导电剂Super P、粘结剂聚偏二氟乙烯(PVDF)在N-甲基吡咯烷酮(NMP)中制成正极浆料。正极浆料中固体含量为50wt％，固体成分中LiNi0.8Co0.1Mn0.1O2、Super P、PVDF的质量比为8:1:1。将正极浆 料涂布在集流体铝箔上并在85℃下烘干后进行冷压，然后进行切边、裁片、分条后，在85℃的真空条件下烘干4h，制成正极极片。
(3)负极极片的制备：
采用厚度为8μm的铜箔作为负极集流体。
将作为负极活性材料的石墨与导电剂Super P、增稠剂CMC、粘接剂丁苯橡胶(SBR)在去离子水中混合均匀，制成负极浆料。负极浆料中固体含量为30wt％，固体成分中石墨、Super P、CMC及粘接剂丁苯橡胶(SBR)的质量比为80:15:3:2。将负极浆料涂布在集流体铜箔上并在85℃下烘干，然后进行冷压、切边、裁片、分条后，在120℃真空条件下烘干12h，制成负极极片。
(4)电解液的制备
在含水量小于10ppm的环境下，将非水有机溶剂碳酸乙烯酯EC、碳酸二乙酯DMC按照体积比1:1进行混合得到电解液溶剂，随后将锂盐和混合后的溶剂混合，配置成锂盐浓度为1mol/L的电解液。
(5)锂离子电池的制备：
以16μm的聚乙烯薄膜(PE)作为隔离膜。将上述正极极片、隔离膜、负极极片按顺序叠好，使隔离膜处于正极极片和负极极片之间起到隔离作用，然后卷绕得到电极组件；将电极组件置于外包装壳中，干燥后注入电解液，经过真空封装、静置、化成、整形等工序，得到锂离子电池(软包锂离子电池的厚度4.0mm、宽度60mm、长度140mm)。
实施例2至实施例14
实施例2至实施例14采用与实施例1相似的方法制备锂离子电池，与实施例1不同的是，实施例2至实施例14调整了有机组分和电解液添加剂的种类和添加量。
实施例15至实施例18
实施例15至实施例18采用与实施例10相似的方法制备锂离子电池，与实施例10不同的是，实施例15至实施例18调整了有机组分所形成的包覆层的孔隙率。
实施例19至实施例20
实施例19至实施例20采用与实施例10相似的方法制备锂离子电池，与实施例10不同的是，实施例19至实施例20调整了电解液添加剂的种类为多种。
实施例21至实施例23
实施例21至实施例23采用与实施例10相似的方法制备锂离子电池，与实施例10不同的是，实施例21至实施例23调整了有机组分为小分子单体化合物。
对比例1
对比例1采用与实施例1相似的方法制备锂离子电池，与实施例1不同的是，对比例1中未设置有机组分和第一添加剂。
实施例2至实施例23以及对比例1的参数如表1所示：
表1
表2
  25℃，600圈后容量保持率/％ 60℃存储30天后体积增长率/％ DCR/mΩ
对比例1 77.2 15.9 20.3
实施例1 92.3 10.9 18.8
实施例2 91.3 12.1 19.1
实施例3 90.8 11.9 19.4
实施例4 91.2 11.3 19.9
实施例5 90.4 14.1 19.3
实施例6 91.8 10.6 20.1
实施例7 88.8 13.8 20.1
实施例8 89.2 10.1 20.8
实施例9 92.5 10.5 18.9
实施例10 94.7 9.9 20.1
实施例11 94.5 9.5 21.4
实施例12 92.4 10.8 18.9
实施例13 94.6 9.4 23
实施例14 94.5 10.3 20.8
实施例15 96.1 9.9 19.3
实施例16 96.3 10.2 19.4
实施例17 96.1 10.5 19.1
实施例18 96.0 10.4 19.5
实施例19 96.3 10.1 19.7
实施例20 96.5 10.0 19.6
实施例21 93.4 10.0 18.3
实施例22 92.7 9.6 18.7
实施例23 92.8 9.8 18.4
从表1和表2可以看出：
对比例1未对活性组分进行包覆，活性组分的结构稳定性较差，二次电池的循环性能相对较差。本申请实施例在活性组分的表面包覆有机组分，可以对活性组分进行防护，能够提高二次电池的功率特性(较低的直流阻抗)和循环特性。且有机组分为交联聚合状态(实施例1至实施例20)和单体状态(实施例21至实施例23)均可以对活性组分起到防护作用。
实施例1至实施例8中，有机组分的添加含量在特定范围内0.1≤A≤0.5；尤其是0.2≤A≤0.4，能够进一步提高二次电池的循环特性和功率特性。
实施例9至实施例20中，通过在电解液中含有具有对称分子结构的添加剂，能够抑制高温时的产气，并提高二次电池的循环特性。
测试部分:
(1)锂离子电池循环性能测试
在45℃下，先以1C恒定电流将锂离子电池充电至4.2V，进一步以4.2V恒定电压充电至电流为0.05C，然后以1C恒定电流将锂离子电池放电至2.8V，以此为一个充放电循环过程，此次的放电容量为锂离子电池首次循环后的放电容量。将锂离子电池按照上述方法进行600次循环充电/放电测试。
锂离子电池循环600次后的容量保持率(％)＝循环600次后的放电容量/首次循环后的放电容量×100％。
(2)60℃存储产气
60℃下，1C恒流充电到4.25V，恒压充电到0.05C，此时利用排水法测试一下体积，此时体积记录为V0，随后将此电池放置在60℃的恒温烘箱中，进行60℃存储30天，存储后从烘箱中取出，待稳定恢复至常温后再进行排水法测试体积，此时体积记录为V1，计算30天后的体积增长率为P＝(V1-V0)/V0*100％
(3)25℃DCR(直流阻抗)
室温条件下，锂离子电池以1C恒流充电到4.25V，恒压充电至电流为0.05C，电池满充后，静置5min,1C放电30min,(电芯带电量为50％SOC)，静置5min，调节温度为25℃，静置1h，记录此时电芯的电压V1，0.4C放电15s，记录脉冲放电后的电压V2，则电芯50％SOC时的DCR为R＝(V1-V2)/I,I＝0.4C。
尽管已经演示和描述了说明性实施例，本领域技术人员应该理解上述实施例不能被解释为对本申请的限制，并且可以在不脱离本申请的精神、原理及范围的情况下对实施例进行改变，替代和修改。

Claims (17)

  1. 一种正极活性材料，其特征在于，包括：
    活性组分；以及
    包含有机组分的包覆层，其包覆于所述活性组分的至少部分表面，所述有机组分包括式(1)所示的化合物和/或经式(1)所示的化合物交联聚合形成的聚合物，
    所述式(1)中，
    M选自磷原子、硼原子或硫原子；
    R选自氧原子、C1-C20烷氧基、经取代或未经取代的C6-C25芳香酚基和经取代或未取代的C5-C25的杂芳香酚基中的一种或多种；
    n表示R基团的数量，n选自2或3。
  2. 根据权利要求1所述的正极活性材料，其特征在于，所述活性组分包括以下组分中的至少一种：
    LisTqNiaCobMncM(1-a-b-c)Yt，其中，0≤s≤2.1，0≤q≤2.1，且0.9≤s+q≤2.1；0≤a≤1，0≤b≤1，0≤c≤1，且0.1≤a+b+c≤1；1.8≤t≤3.5；T选自Na、K、Mg中的一种或几种；M选自B、Mg、Al、Si、P、S、Ca、Sc、Ti、V、Cr、Fe、Cu、Zn、Sr、Y、Zr、Nb、Mo、Cd、Sn、Sb、Te、Ba、Ta、W、Yb、La、Ce中的一种或几种；Y选自O、F中的一种或多种；
    xLi2MnO3·(1-x)LiMnyB1-yO2，其中，0.1≤x≤0.9，0.1≤y≤0.9，B选自Ni、Co、B、Mg、Al、Si、P、S、Ca、Sc、Ti、V、Cr、Fe、Cu、Zn、Sr、Y、Zr、Nb、Mo、Cd、Sn、Sb、Te、Ba、Ta、W、Yb、La、Ce中的一种或多种。
  3. 根据权利要求1或2所述的正极活性材料，其特征在于，所述M包括磷原子，所述式(1)所示的化合物包括式(I)和/或式(II)所示的化合物：
    式(I)和式(II)中，
    R1、R2、R3和R4各自独立地选自氢原子、经取代或未取代的C1-C20烷基、经取代或未取代的C6-C25芳基、或者经取代或未取代的C5-C25的杂芳香基；
    可选地，R1、R2、R3和R4各自独立地选自C1-C3烷基、苯基、萘基、蒽基、菲基、二联苯基或三联苯基。
  4. 根据权利要求3所述的正极活性材料，其特征在于，所述式(I)所示的化合物包括式(P-11)至式(P-16)所示化合物中的一种或多种：
    和/或
    所述式(II)所示的化合物包括式(P-21)和/或式(P-22)所示化合物：
  5. 根据权利要求1或2所述的正极活性材料，其特征在于，所述M包括硼原子，所述式(1)所示的化合物包括式(III)所示的化合物：
    式(III)中，
    R6和R7各自独立地选自氢原子、经取代或未取代的C1-C20烷基、经取代或未取代的C6-C25芳基、或者经取代或未取代的C5-C25的杂芳香基；
    可选地，R6和R7各自独立地选自C1-C3烷基、苯基、萘基、蒽基、菲基、二联苯基或三联苯基。
  6. 根据权利要求5所述的正极活性材料，其特征在于，所述式(III)所示的化合物包括式(B-1)至式(B-3)所示化合物中的一种或多种：
  7. 根据权利要求1或2所述的正极活性材料，其特征在于，所述M包括硫原子，所述式(1)所示的化合物包括式(IV)所示的化合物：
    式(IV)中，
    R5选自氢原子、经取代或未取代的C1-C20烷基、经取代或未取代的C6-C25芳基、或者经取代或未取代的C5-C25的杂芳香基；
    可选地，R5各自独立地选自C1-C3烷基、苯基、萘基、蒽基、菲基、二联苯基或三联苯基。
  8. 根据权利要求7所述的正极活性材料，其特征在于，所述式(IV)所示的化合物包括式(S-1)和/或式(S-2)所示化合物：
  9. 根据权利要求1至8中任一项所述的正极活性材料，其特征在于，所述包覆层包括经式(1)所示的化合物交联聚合形成的聚合物；
    所述聚合物的重均分子量为500Da至2000Da；可选为1000Da至1500Da；和/或
    所述包覆层的孔隙率为5％至20％。
  10. 根据权利要求1至9中任一项所述的正极活性材料，其特征在于，
    基于所述正极活性材料的总质量计，所述有机组分在所述正极活性材料中的质量含量记为A％，0.1≤A≤0.5；可选地，0.2≤A≤0.4；和/或
    所述包覆层的厚度为5μm至20μm；可选为5μm至10μm。
  11. 一种二次电池，其特征在于，包括：正极极片、负极极片、设置于所述正极极片和所述负极极片之间的隔离膜以及电解液，所述正极极片包括如权利要求1至10中任一项所述的正极活性材料。
  12. 根据权利要求11所述的二次电池，其特征在于，
    所述电解液包括第一添加剂，所述第一添加剂被配置为在所述正极活性材料表面成膜，其中，所述第一添加剂包括具有硫、磷、硼中至少一种杂环元素的含氧杂环化合物，且所述含氧杂环化合物包括以碳碳单键对称的镜像结构。
  13. 根据权利要求12所述的二次电池，其特征在于，所述第一添加剂包括式(2)至式(5)所示化合物中的一种或多种：
  14. 根据权利要求12或13所述的二次电池，其特征在于，
    基于所述正极活性材料的总质量计，所述有机组分在所述正极活性材料中的质量含量记为A％；
    基于所述电解液的总质量计，所述第一添加剂在所述电解液中的质量含量记为B％，
    其中，所述二次电池满足：0.5≤B/A≤2。
  15. 根据权利要求12至14中任一项所述的二次电池，其特征在于，
    基于所述电解液的总质量计，所述第一添加剂在所述电解液中的质量含量记为B％，0.10≤B≤0.70。
  16. 根据权利要求13至15中任一项所述的二次电池，其特征在于，
    所述第一添加剂包括式(2)所示化合物至式(5)所示化合物中的至少两种；
    基于所述第一添加剂的总摩尔量记，所述第一添加剂中的其中一种化合物的摩尔含量，与其中另一种化合物的摩尔含量的比值记为C，1≤C≤2；可选地，1.2≤C≤1.5。
  17. 一种用电装置，其特征在于，包括如权利要求12至16中任一项所述的二次电池。
PCT/CN2023/073929 2022-03-10 2023-01-31 正极活性材料、二次电池、电池模块、电池包和用电装置 WO2023169096A1 (zh)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2025091824A1 (zh) * 2023-11-03 2025-05-08 宁德时代新能源科技股份有限公司 电池和用电装置
WO2025148396A1 (zh) * 2024-01-11 2025-07-17 宁德时代新能源科技股份有限公司 电极片及其制备方法、电池及用电装置

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117117160B (zh) * 2023-10-24 2024-04-05 宁德时代新能源科技股份有限公司 正极活性材料及其制备方法、正极极片、电池和用电装置

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11307081A (ja) * 1998-04-17 1999-11-05 Shin Kobe Electric Mach Co Ltd リチウムイオン二次電池及びその製造方法
JP2002352804A (ja) * 2001-05-28 2002-12-06 Hitachi Maxell Ltd 非水二次電池
CN105914401A (zh) * 2016-06-27 2016-08-31 宁德时代新能源科技股份有限公司 一种电解液以及包含该电解液的锂离子电池
CN107492660A (zh) * 2016-06-13 2017-12-19 宁德新能源科技有限公司 正极浆料、正极片及锂离子电池
CN108539122A (zh) * 2018-03-26 2018-09-14 横店集团东磁股份有限公司 一种正极片及包含该正极片的锂离子二次电池
CN108832103A (zh) * 2018-06-20 2018-11-16 江苏翔鹰新能源科技有限公司 一种改性高镍三元正极材料及其制备方法和应用
CN109728340A (zh) * 2017-10-30 2019-05-07 宁德时代新能源科技股份有限公司 锂离子电池
WO2021200394A1 (ja) * 2020-03-31 2021-10-07 パナソニックＩｐマネジメント株式会社 非水電解質二次電池

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6807010B2 (ja) * 2015-06-18 2021-01-06 日本電気株式会社 リチウム二次電池用正極活物質、リチウム二次電池用正極、リチウム二次電池及びこれらの製造方法
JP6774415B2 (ja) * 2015-08-11 2020-10-21 昭和電工株式会社 リチウムイオン二次電池の正極用スラリー、リチウムイオン二次電池の正極用スラリーを用いて得られるリチウムイオン二次電池用正極およびその製造方法、並びに、リチウムイオン二次電池用正極を備えたリチウムイオン二次電池およびその製造方法
KR101748037B1 (ko) * 2015-10-07 2017-06-15 주식회사 엘지화학 전기화학 성능이 우수한 양극활물질 및 이를 포함하는 리튬 이차 전지
JP7107196B2 (ja) * 2018-12-04 2022-07-27 株式会社豊田自動織機 二次電池

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11307081A (ja) * 1998-04-17 1999-11-05 Shin Kobe Electric Mach Co Ltd リチウムイオン二次電池及びその製造方法
JP2002352804A (ja) * 2001-05-28 2002-12-06 Hitachi Maxell Ltd 非水二次電池
CN107492660A (zh) * 2016-06-13 2017-12-19 宁德新能源科技有限公司 正极浆料、正极片及锂离子电池
CN105914401A (zh) * 2016-06-27 2016-08-31 宁德时代新能源科技股份有限公司 一种电解液以及包含该电解液的锂离子电池
CN109728340A (zh) * 2017-10-30 2019-05-07 宁德时代新能源科技股份有限公司 锂离子电池
CN108539122A (zh) * 2018-03-26 2018-09-14 横店集团东磁股份有限公司 一种正极片及包含该正极片的锂离子二次电池
CN108832103A (zh) * 2018-06-20 2018-11-16 江苏翔鹰新能源科技有限公司 一种改性高镍三元正极材料及其制备方法和应用
WO2021200394A1 (ja) * 2020-03-31 2021-10-07 パナソニックＩｐマネジメント株式会社 非水電解質二次電池

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2025091824A1 (zh) * 2023-11-03 2025-05-08 宁德时代新能源科技股份有限公司 电池和用电装置
WO2025148396A1 (zh) * 2024-01-11 2025-07-17 宁德时代新能源科技股份有限公司 电极片及其制备方法、电池及用电装置

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