CN115832268B - Ternary positive electrode material, method for producing the same, and secondary battery using the same - Google Patents
Ternary positive electrode material, method for producing the same, and secondary battery using the same Download PDFInfo
- Publication number
- CN115832268B CN115832268B CN202210269050.4A CN202210269050A CN115832268B CN 115832268 B CN115832268 B CN 115832268B CN 202210269050 A CN202210269050 A CN 202210269050A CN 115832268 B CN115832268 B CN 115832268B
- Authority
- CN
- China
- Prior art keywords
- positive electrode
- electrode material
- ternary
- lithium
- solution
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- 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
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- 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
- H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
-
- 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
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Inorganic Chemistry (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
The application provides a ternary positive electrode material, a manufacturing method thereof and a secondary battery using the ternary positive electrode material. The ternary positive electrode material is a polycrystalline nickel-cobalt-manganese positive electrode material and comprises secondary particles composed of primary particles, wherein the secondary particles are in a core-shell structure, the core part of the secondary particles is composed of radially arranged primary particles growing in a radial strip shape, and the shell part of the secondary particles is composed of unordered primary particles. With such a configuration, the lithium ion transfer efficiency can be improved, and the stability of the material can be ensured, so that the specific capacity of the secondary battery can be further improved while the capacity retention rate of the secondary battery is ensured.
Description
Technical Field
The application relates to the technical field of secondary batteries, in particular to a ternary positive electrode material for a secondary battery, a manufacturing method thereof and a secondary battery using the ternary positive electrode material.
Background
In recent years, as the application range of secondary batteries is becoming wider, secondary batteries are widely used in energy storage power systems such as hydraulic power, thermal power, wind power and solar power stations, and in various fields such as electric tools, electric bicycles, electric motorcycles, electric vehicles, military equipment, aerospace and the like. As secondary batteries have been greatly developed, there are also demands for higher energy density, cycle performance, service life, and the like. For the positive electrode material used in the secondary battery, it is required to have high energy density, high lithium ion transport efficiency, high stability, and the like, but the current positive electrode material is still to be improved.
Disclosure of Invention
The present application has been made in view of the above-described problems, and an object of the present application is to provide a positive electrode material which has improved stability in use and improved specific capacity and capacity retention rate of a secondary battery using the positive electrode material by improving its structure and shortening the lithium ion transport distance inside the material, thereby improving lithium ion transport efficiency, and having a corrosion-resistant layer outside the positive electrode material.
In order to achieve the above object, the present application provides the following positive electrode material, a method for producing the same, and a secondary battery, a battery module, a battery pack, and an electric device using the positive electrode material.
The first aspect of the application provides a ternary positive electrode material, wherein the ternary positive electrode material is a polycrystalline nickel-cobalt-manganese positive electrode material, the ternary positive electrode material comprises secondary particles composed of primary particles, the secondary particles are in a core-shell structure, a core part of the ternary positive electrode material is composed of radially arranged primary particles growing in a long way, and a shell part of the ternary positive electrode material is composed of unordered primary particles.
The application provides a ternary positive electrode material, which is provided with the secondary particles of the core-shell structure, wherein primary particles which radially grow in a long shape in the radial direction of the core part in the core-shell structure are utilized to shorten the path (the grain boundary of the primary particles) which lithium ions pass through when the lithium ions are transmitted inside the secondary particles, so that the transmission efficiency of the lithium ions is improved, the structure can also effectively improve the volume change when the lithium ions are embedded/extracted, and in addition, the shell part in the core-shell structure is formed by the primary particles which are randomly arranged, the radial structure of the core part is wrapped from the outside, and separation and disintegration caused by relatively weak binding force among the primary particles in the inner radial structure are reduced, so that the use stability of the material can be ensured in the cycle process of the lithium ions are embedded/extracted.
In any embodiment, the core comprises at least one element selected from boron or phosphorus, optionally boron. By doping the core with any one of boron and phosphorus, the grain growth of the core of the ternary cathode material is facilitated to induce preferential growth of a certain crystal plane, and long-strip-shaped primary particles are formed, and the primary particles form radially arranged core.
In any embodiment, the doping concentration of the at least one element selected from boron and phosphorus in the core is 100-10000ppm, optionally 500-3000ppm, so that the core grain growth of the ternary positive electrode material is beneficial to inducing the preferential growth of a certain crystal face to form a core formed by primary particles which grow radially and are arranged radially. On the other hand, boron or phosphorus cannot be used as an active ingredient in the positive electrode material, and therefore, by falling within the above-described range, it can be ensured that the capacity of the secondary battery is not reduced.
In any embodiment, the shell portion comprises at least one element selected from zirconium, titanium, aluminum, optionally zirconium. Therefore, primary particles in the shell of the ternary positive electrode material can grow randomly, so that the positive electrode material is not easy to separate and separate in the cycle process of lithium ion intercalation/deintercalation, and further the side reaction between the surface of the positive electrode material and electrolyte can be relieved by doping of zirconium, titanium and aluminum into the ternary positive electrode material, so that the corrosion resistance of the positive electrode material is improved, and the service stability of the material is further improved.
In any embodiment, the doping concentration of at least one element selected from zirconium, titanium and aluminum in the shell part is 200-10000ppm, optionally 1000-5000ppm. Therefore, the corrosion resistance of the surface of the positive electrode material is improved, and the use stability of the material is improved. On the other hand, zirconium, titanium, and aluminum are not available as or active components in the positive electrode material, and therefore, the charge-discharge capacity and cycle stability of the material can be simultaneously achieved by the above-described doping concentration ranges.
In any embodiment, the core has an average diameter of 3 to 15 μm. Therefore, the structural stability of the core part can be kept, and the secondary particles of the positive electrode material are not easy to crack.
In any embodiment, the shell portion has an average thickness of 0.5 μm or more. Therefore, the core-shell structure of the secondary particles of the positive electrode material can be kept stable, and the secondary particles are not easy to crack.
In any embodiment, the secondary particles of the ternary positive electrode material have an average particle size of 3.5 to 18 μm. Therefore, the core-shell structure of the secondary particles of the positive electrode material can be kept stable, and the secondary particles are not easy to crack.
The second aspect of the application also provides a manufacturing method of the ternary positive electrode material, wherein the ternary positive electrode material is a nickel-cobalt-manganese positive electrode material,
The manufacturing method comprises the following steps:
Firstly, mixing nickel salt, cobalt salt, manganese salt and water to prepare a first mixed solution;
Step two, respectively preparing a second solution and a third solution, wherein the second solution contains boron element and/or phosphorus element, the third solution contains at least one element selected from zirconium element, titanium element and aluminum element,
Continuously supplying a first mixed solution, a second solution and a precipitant and/or a complexing agent into a reaction kettle, and controlling the temperature in the reaction kettle to react to obtain a first precursor product;
Switching the supply source of the second solution in the third step into the supply source of the third solution, continuously supplying the first mixed solution, the third solution and the precipitant and/or the complexing agent into the reaction kettle, and continuing the reaction to obtain a second precursor product;
Aging, washing and solid-liquid separating a precipitate containing the second precursor product to obtain a doped nickel-cobalt-manganese precursor;
and step six, uniformly mixing the doped nickel-cobalt-manganese precursor with a lithium source, and then roasting at a high temperature in an oxygen atmosphere to obtain the ternary anode material.
Thus, a ternary positive electrode material having a core-shell structure in which the core portion is doped with boron element and/or phosphorus element and the shell portion is doped with at least one element selected from zirconium element, titanium element, and aluminum element can be produced. Boron and/or phosphorus are doped in the growth process of the core part of the ternary positive electrode material particles, so that the primary particles of the core part can induce a certain crystal face to preferentially grow, and the core part formed by radially arranged radially long-shaped primary particles is formed, so that the transmission efficiency of lithium ions is improved. By doping at least one element selected from zirconium element, titanium element and aluminum element in the growth process of the shell part of the ternary positive electrode material particle, primary particles of the shell part of the ternary positive electrode material particle can grow randomly, so that the positive electrode material is not easy to separate and disintegrate in the cycle process of lithium ion intercalation/deintercalation, and the side reaction between the surface of the positive electrode material and electrolyte can be relieved by doping of zirconium, titanium and aluminum, so that the corrosion resistance of the positive electrode material is improved, and the service stability of the material is further improved.
In any embodiment, in the third step, the reaction time is controlled such that the average particle size of the particles in the first precursor product is 3-15 μm. Therefore, the structural stability of the core part can be kept, and the secondary particles of the positive electrode material are not easy to crack.
In any embodiment, in step four, the reaction time is controlled such that the average particle size of the particles in the second precursor product is 3.5-18 μm. Therefore, the core-shell structure of the secondary particles of the positive electrode material can be kept stable, and the secondary particles are not easy to crack.
In any embodiment, in the third step, the feeding speed of the first mixed solution and the second solution is controlled so that the molar ratio of the content of the boron element and/or the phosphorus element in the fed second solution to the total content of the nickel element, the cobalt element and the manganese element in the first mixed solution is 1:100-1:1000;
in any embodiment, in the fourth step, the feeding speed of the first mixed solution and the third solution is controlled so that the molar ratio of the content of the zirconium element and/or the titanium element and/or the aluminum element in the fed third solution to the total content of the nickel, cobalt and manganese elements in the first mixed solution is 1:100-1:1000.
Thus, in the obtained positive electrode material, a core-shell structure having a core portion doped with boron and/or phosphorus and a shell portion doped with at least one element selected from zirconium, titanium, and aluminum can be formed, whereby a core portion in which primary particles radially grow in a long-length manner and a shell portion in which primary particles grow in a disordered manner can be obtained. By the above-described supply rates of the second solution and the third solution, it is possible to improve both the lithium ion transport efficiency of the secondary battery, the stability in use of the positive electrode material, and the charge/discharge capacity of the secondary battery.
In any embodiment, in the third step and the fourth step, the temperature in the reaction kettle is controlled to be 50-70 ℃, so that boron element and/or phosphorus element is easily doped into the core part of the ternary positive electrode material precursor, and zirconium element, titanium element and/or aluminum element is easily doped into the shell part of the ternary positive electrode material precursor.
In any embodiment, in the sixth step, the baking temperature is 700-1000 ℃, so that the ternary cathode material precursor with the core-shell structure is baked into the ternary cathode material with the core part doped with boron element and/or phosphorus element and the shell part doped with at least one element selected from zirconium element, titanium element and aluminum element.
In any embodiment, the nickel salt, cobalt salt and manganese salt are at least one selected from sulfate, nitrate, acetate and hydrochloride respectively, the boron element is at least one selected from boric acid, boron trioxide, boron trifluoride and monofluoroboric acid, the phosphorus element is at least one selected from sodium phosphate, sodium dihydrogen phosphate, potassium phosphate, ammonium phosphate and monoammonium phosphate, the zirconium element is at least one selected from zirconium chloride, zirconium oxychloride, zirconium acetate and zirconium citrate, the titanium element is at least one selected from titanium trichloride, titanium tetrachloride and titanium nitrate, the aluminum element is at least one selected from aluminum sulfate, sodium metaaluminate, aluminum chloride and aluminum nitrate, and the lithium source is at least one selected from lithium hydroxide, lithium carbonate, lithium nitrate, lithium chloride, lithium fluoride, lithium phosphate, lithium acetate, lithium formate, lithium citrate and n-butyl lithium. Thus, it is easy to incorporate the zirconium element, the titanium element and/or the aluminum element into the shell portion of the ternary positive electrode material precursor by incorporating the boron element and/or the phosphorus element into the core portion of the ternary positive electrode material precursor at a reaction temperature of 50 to 70 ℃, and further to obtain the nickel-cobalt-manganese ternary positive electrode material in which the boron element and/or the phosphorus element is doped into the core portion and the zirconium element, the titanium element and/or the aluminum element is doped into the shell portion by baking at a baking temperature of 700 to 1000 ℃, without excessively containing other impurity elements.
In any embodiment, the molar ratio of nickel to cobalt to manganese in the first mixed solution is x, y and z, wherein x is more than or equal to 0.5 and less than or equal to 1, y is more than or equal to 0 and less than or equal to 0.5, z is more than or equal to 0 and less than or equal to 0.5, and x+y+z=1. Therefore, the obtained ternary positive electrode material has higher nickel content, and the specific capacity of the ternary positive electrode material is effectively improved.
The third aspect of the present application also provides a secondary battery comprising the positive electrode active material of the first aspect of the present application or the positive electrode active material produced by the production method according to the second aspect of the present application.
A fourth aspect of the application provides a battery module comprising the secondary battery of the third aspect of the application.
A fifth aspect of the application provides a battery pack comprising the battery module of the fourth aspect of the application.
A sixth aspect of the application provides an electric device comprising at least one selected from the secondary battery of the third aspect of the application, the battery module of the fourth aspect of the application, or the battery pack of the fifth aspect of the application.
Thus, the present application can provide a secondary battery, which has improved lithium ion transport efficiency and can maintain stability of a positive electrode material while improving specific capacity and capacity retention, and a battery pack, a battery module, and an electric device including the same.
Drawings
Fig. 1 is a schematic view of the general structure of a ternary positive electrode material secondary particle according to an embodiment of the present application.
Fig. 2 is a scanning electron microscope image of ternary positive electrode material precursor particles (after grinding) of example 4.
Fig. 3 is a scanning electron microscope image of the secondary particles of the ternary positive electrode material precursor particles of comparative example 1.
Fig. 4 is a scanning electron microscope image of the secondary particles of the ternary positive electrode material precursor particles of comparative example 4.
Fig. 5 is a schematic view of a secondary battery according to an embodiment of the present application.
Fig. 6 is an exploded view of the secondary battery according to an embodiment of the present application shown in fig. 5.
Fig. 7 is a schematic view of a battery module according to an embodiment of the present application.
Fig. 8 is a schematic view of a battery pack according to an embodiment of the present application.
Fig. 9 is an exploded view of the battery pack of the embodiment of the present application shown in fig. 8.
Fig. 10 is a schematic view of an electric device in which a secondary battery according to an embodiment of the present application is used as a power source.
Reference numerals illustrate:
1 battery pack, 2 upper case, 3 lower case, 4 battery module, 5 secondary battery, 51 case, 52 electrode assembly, 53 top cover assembly.
Detailed Description
Hereinafter, embodiments of the positive electrode active material, the method for producing the same, the positive electrode sheet, the secondary battery, the battery module, the battery pack, and the electric device according to the present application are specifically disclosed with reference to the accompanying drawings. However, unnecessary detailed description may be omitted. For example, detailed descriptions of well-known matters and repeated descriptions of the actual same structure may be omitted. This is to avoid that the following description becomes unnecessarily lengthy, facilitating the understanding of those skilled in the art. Furthermore, the drawings and the following description are provided for a full understanding of the present application by those skilled in the art, and are not intended to limit the subject matter recited in the claims.
The "range" disclosed herein is defined in terms of lower and upper limits, with the given range being defined by the selection of a lower and an upper limit, the selected lower and upper limits defining the boundaries of the particular range. Ranges that are defined in this way can be inclusive or exclusive of the endpoints, and any combination can be made, i.e., any lower limit can 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, it is understood that ranges of 60-110 and 80-120 are also contemplated. Furthermore, if minimum range values 1 and 2 are listed, and if maximum range values 3,4, and 5 are listed, then the following ranges are all contemplated as 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In the present application, unless otherwise indicated, the numerical range "a-b" represents a shorthand representation of any combination of real numbers between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed throughout, and "0-5" is simply a shorthand representation of a combination of these values. When a certain parameter is expressed as an integer of 2 or more, it is disclosed that the parameter is, for example, an integer of 2,3, 4, 5, 6,7, 8, 9, 10, 11, 12 or the like.
All embodiments of the application and alternative embodiments may be combined with each other to form new solutions, unless otherwise specified.
All technical features and optional technical features of the application may be combined with each other to form new technical solutions, unless specified otherwise.
All the steps of the present application may be performed sequentially or randomly, preferably sequentially, unless otherwise specified. For example, the method comprises steps (a) and (b), meaning that the method may comprise steps (a) and (b) performed sequentially, or may comprise steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c), may include steps (a), (c) and (b), may include steps (c), (a) and (b), and the like.
The terms "comprising" and "including" as used herein mean open ended or closed ended, unless otherwise noted. For example, the terms "comprising" and "comprises" may mean that other components not listed may be included or included, or that only listed components may be included or included.
The term "or" is inclusive in this application, unless otherwise specified. For example, the phrase "a or B" means "a, B, or both a and B. More specifically, either condition satisfies the condition "A or B" that A is true (or present) and B is false (or absent), that A is false (or absent) and B is true (or present), or that both A and B are true (or present).
[ Ternary cathode Material ]
In one embodiment of the present application, a ternary cathode material is provided, which is a polycrystalline nickel cobalt manganese-based cathode material, including secondary particles composed of primary particles, the structure of which is schematically shown in fig. 1. The secondary particles are in a core-shell structure, the core part of the secondary particles is composed of primary particles which grow in a long shape along the radial direction and are arranged in a radial way, and the shell part is composed of the primary particles which are arranged in a disordered way.
Although the mechanism is not clear, the inventor surprisingly found that the ternary cathode material with the core-shell structure can improve the lithium ion transmission efficiency, the charge and discharge capacity and the use stability of the secondary battery, thereby improving the specific capacity and the capacity retention rate of the secondary battery.
In the charge and discharge process of the traditional polycrystalline ternary cathode material, ni 4+ and the like with strong oxidability are generated, so that side reactions are easy to occur with electrolyte, irreversible phase change and the like from the cathode material are caused, capacity decay is accelerated, and service life is prolonged. In addition, in the charge and discharge process, the lithium ion deintercalation process also can cause the cyclic change of the unit cell volume of the positive electrode material, and after repeated cyclic charge and discharge, the stress accumulated by the volume expansion and contraction of the positive electrode material can be released at the grain boundary to cause secondary particle cracking, and the fresh surface is exposed to cause side reaction, so that secondary particle pulverization is invalid. In addition, the conventional polycrystalline ternary cathode material generally comprises secondary particles formed by unordered primary particles, so that the primary particles have numerous grain boundaries, lithium ions are transferred from the secondary particles to form a tortuous path, and the lithium ion transmission efficiency is reduced.
The ternary positive electrode material can structurally alleviate the problems. The core part is formed by primary particles which are radially arranged and grow along the radial direction, so that the transmission distance of lithium ions (grain boundaries among the primary particles) in the core part can be shortened, the lithium ion transmission efficiency is improved, the volume change during the intercalation/deintercalation of the lithium ions can be effectively improved by the structure, the accumulated stress of the positive electrode material in the charge-discharge cycle is relaxed, the secondary particles of the positive electrode material are not easy to crack, and the use stability of the positive electrode material is improved. Secondly, the outer part of the material has a disordered arrangement structure, so that the inner radial structure can be wrapped from the outside, separation and disintegration caused by relatively weak bonding force among primary particles in the inner radial structure are reduced, and the use stability of the material can be ensured. In addition, the shell part of the ternary positive electrode material is doped with the corrosion-resistant component, so that the acidic component in the electrolyte is not easy to permeate into the interior of the particles, and the use stability of the positive electrode material is further improved.
In some embodiments, the core portion of the ternary positive electrode material comprises at least one element of boron or phosphorus, optionally boron. By doping the core with any one of boron and phosphorus, the core of the ternary positive electrode material is favorable for inducing a certain crystal face to preferentially grow when primary grains grow, and the core formed by primary particles which are radially arranged and radially grow in a long shape is formed. Specifically, by doping boron or phosphorus in the core portion, the surface energy of the (003) crystal face of the ternary cathode material can be reduced, and preferential growth of the (003) crystal face is induced, thereby forming a core portion in which elongated primary particles preferentially grown from the (003) crystal face are arranged radially.
In some embodiments, the doping concentration of the at least one element selected from boron or phosphorus in the core is 100-10000ppm, optionally 500-3000ppm, so that the core of the ternary cathode material is beneficial to induce a certain crystal plane to preferentially grow when primary grains grow to form radial primary particles, and the primary particles are radially arranged to form the core growing in long strips. In addition, when the doping concentration is too high, the capacity of the secondary battery is too low because the doping element cannot function as an active ingredient. Therefore, by controlling the doping concentration of boron or phosphorus in the core portion within the above range, both the lithium ion conduction efficiency and the charge-discharge capacity of the ternary cathode material can be achieved.
In some embodiments, the shell portion comprises at least one element selected from zirconium, titanium, aluminum, optionally zirconium. Therefore, primary particles in the shell part of the ternary positive electrode material can grow randomly to wrap the internal radial structure, separation and disintegration caused by relatively weak binding force among the primary particles in the internal radial structure are reduced, and further, the side reaction between the surface of the positive electrode material and electrolyte can be relieved by doping of zirconium, titanium and aluminum into the ternary positive electrode material, so that the corrosion resistance of the positive electrode material is improved, and the service stability of the material is further improved.
In some embodiments, the doping concentration of at least one element selected from zirconium, titanium, aluminum in the shell portion is 200-10000ppm, alternatively 1000-5000ppm. The corrosion resistance of the ternary anode material can be improved by doping zirconium, titanium and aluminum, but the zirconium, titanium and aluminum cannot be used as or are used as active components in the anode material, if the doping concentration is too low and the corrosion resistance is insufficient, the active component duty ratio of the anode can be influenced and the charge-discharge capacity is reduced, so that the charge-discharge capacity and the cycle stability of the material can be both realized through the doping concentration range.
In some embodiments, the core has an average diameter of 3-15 μm. Therefore, the structural stability of the core part can be kept, and the secondary particles of the positive electrode material are not easy to crack. The average thickness of the shell portion is 0.5 μm or more.
In some embodiments, the secondary particles of the ternary positive electrode material have an average particle size of 3.5 to 18 μm. Therefore, the core-shell structure of the secondary particles of the positive electrode material can be kept stable, and the secondary particles are not easy to crack.
In some embodiments, the polycrystalline nickel-cobalt-manganese ternary positive electrode material may contain at least one selected from lithium-nickel-cobalt-manganese oxides such as LiNi 1/3Co1/3Mn1/3O2 (may also be abbreviated as NCM 333)、LiNi0.5Co0.2Mn0.3O2 (may also be abbreviated as NCM 523)、LiNi0.5Co0.25Mn0.25O2) (may also be abbreviated as NCM 211)、LiNi0.6Co0.2Mn0.2O2 (may also be abbreviated as NCM 622)、LiNi0.8Co0.1Mn0.1O2) (may also be abbreviated as NCM 811)) and modified compounds thereof, and the like, and may appropriately contain an additive element such as Mg, fe, W, F within a range that does not affect the growth of the core and shell structures.
[ Method for producing ternary cathode Material ]
In one embodiment of the present application, a method for manufacturing the ternary cathode material is provided, the method comprising the steps of:
Firstly, mixing nickel salt, cobalt salt, manganese salt and water to prepare a first mixed solution;
Preparing a second solution and a third solution respectively, wherein the second solution contains boron element and/or phosphorus element, and the third solution contains at least one element selected from zirconium element, titanium element and aluminum element;
Continuously supplying a first mixed solution, a second solution and a precipitant and/or a complexing agent into a reaction kettle, and controlling the temperature in the reaction kettle to react to obtain a first precursor product;
switching the supply source of the second solution in the third step into the supply source of the third solution, continuously supplying the first mixed solution, the third solution and the precipitant and/or the complexing agent into the reaction kettle, and continuing the reaction to obtain a second precursor product;
aging, washing and solid-liquid separating the precipitate containing the second precursor product to obtain a doped nickel-cobalt-manganese precursor;
And step six, uniformly mixing the doped nickel cobalt manganese precursor with a lithium source, and then roasting at a high temperature in an oxygen atmosphere to obtain the ternary anode material.
In some embodiments, the nickel salt, cobalt salt, and manganese salt used in preparing the first mixed solution are each at least one water-soluble salt selected from sulfate, nitrate, acetate, and hydrochloride. The salts are dissolved in water to prepare a first mixed solution, wherein the molar ratio of nickel ions, cobalt ions and manganese ions, x, is controlled to be x, is more than or equal to 0.5 and less than or equal to 1, is more than or equal to 0 and less than or equal to 0.5, and is x+y+z=1. By increasing the nickel ion content, the specific capacity of the ternary positive electrode material can be increased. In addition, the total concentration of nickel, cobalt and manganese in the mixed salt solution is 1-3mol/L.
In some embodiments, the boron element in the second solution is derived from at least one water-soluble fluorine-containing compound selected from boric acid, boron trioxide, boron trifluoride, monofluoroboric acid, and the like, and the phosphorus element is derived from at least one water-soluble phosphorus-containing compound selected from sodium phosphate, sodium dihydrogen phosphate, potassium phosphate, ammonium dihydrogen phosphate, and the like. The total concentration of boron and/or phosphorus in the second solution is generally adjusted to 0.1 to 1mol/L from the viewpoint of enabling efficient doping and facilitating radial growth of radially elongated primary particles.
In some embodiments, the zirconium element in the third solution is derived from at least one water-soluble zirconium salt selected from zirconium chloride, zirconium oxychloride, zirconium acetate, zirconium citrate, and the like, the titanium element is derived from at least one water-soluble titanium salt selected from titanium trichloride, titanium tetrachloride, titanium nitrate, and the like, and the aluminum element is derived from at least one water-soluble aluminum-containing salt selected from aluminum sulfate, sodium metaaluminate, aluminum chloride, aluminum nitrate, and the like. The total concentration of zirconium, titanium and aluminum in the third solution is generally adjusted to 0.1 to 1mol/L from the viewpoint of effective doping and improvement of corrosion resistance.
In some embodiments, the reaction environment in the reaction vessel is adjusted to and maintained at 50-70 ℃ at atmospheric pressure prior to adding the first mixed solution, the second solution, and the reaction vessel to react. In addition, in the third step, the first mixed solution and the second solution are continuously added at the same time as the precipitant and/or the complexing agent are added from different feed inlets according to the requirement. The precipitant includes sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, etc., sodium hydroxide is preferable from the viewpoint of cost, the complexing agent includes ammonia water, ammonium chloride, ammonium nitrate, ammonium sulfate, etc., and ammonia water is preferable from the viewpoint of cost. In the third step, the feeding speed of the first mixed solution and the second solution is controlled so that the molar ratio of the total addition amount of boron and phosphorus to the nickel cobalt manganese element is 1:100-1:1000, alternatively 1:100-1:500, from the standpoint of facilitating doping and radial growth of radially elongated primary particles.
The reaction environment of the reaction kettle in the fourth step is usually maintained as above, and can be regulated as required. In the fourth step, the feeding speed of the first mixed solution and the third solution is controlled so that the molar ratio of the total addition amount of the zirconium element and/or the titanium element and/or the aluminum element to the nickel-cobalt-manganese element is 1:100-1:1000 from the viewpoint of facilitating doping and improving corrosion resistance.
In the third and fourth steps, the average particle size of the particles in the sample can be tested by sucking the sample from the discharge port at any time to monitor and control the particle size of the obtained first precursor product or second precursor product in real time.
The lithium source used in the sixth step is derived from at least one selected from the group consisting of lithium hydroxide, lithium carbonate, lithium nitrate, lithium chloride, lithium fluoride, lithium phosphate, lithium acetate, lithium formate, lithium citrate, and n-butyllithium. The lithium source may be in the form of particles, which may have a particle size of 300-400 μm. Mixing the second precursor product and particles containing a lithium source in a molar ratio of nickel cobalt manganese element to lithium element of 1:1.03-1:1.2, and roasting at a roasting temperature of 700-1000 ℃ for 6-15 hours in an oxygen atmosphere to obtain the nickel cobalt manganese ternary cathode material with the core part doped with boron and/or phosphorus and the shell part doped with zirconium, titanium and/or aluminum.
[ Secondary Battery ]
In one embodiment of the present application, a secondary battery is provided.
In general, a secondary battery includes a positive electrode tab, a negative electrode tab, an electrolyte, and a separator. During the charge and discharge of the battery, active ions are inserted and extracted back and forth between the positive electrode plate and the negative electrode plate. The electrolyte plays a role in ion conduction between the positive electrode plate and the negative electrode plate. The isolating film is arranged between the positive pole piece and the negative pole piece, and mainly plays a role in preventing the positive pole piece and the negative pole piece from being short-circuited, and meanwhile ions can pass through the isolating film.
[ Positive electrode sheet ]
The positive electrode plate comprises a positive electrode current collector and a positive electrode film layer arranged on at least one surface of the positive electrode current collector, wherein the positive electrode film layer comprises the positive electrode active material of the first aspect of the application.
As an example, the positive electrode current collector has two surfaces opposing in its own thickness direction, and the positive electrode film layer is provided on either one or both of the two surfaces opposing the positive electrode current collector.
In some embodiments, the positive current collector may employ a metal foil or a composite current collector. For example, as the metal foil, aluminum foil may be used. The composite current collector may include a polymeric material base layer and a metal layer formed on at least one surface of the polymeric material base layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel alloy, titanium alloy, silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).
In some embodiments, the positive electrode active material may also include a portion of other positive electrode active materials known in the art for use in batteries, such as, for example, lithium cobalt oxide (e.g., liCoO 2), lithium nickel oxide (e.g., liNiO 2), lithium manganese oxide (e.g., liMnO 2、LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, or modified compounds thereof, and the like.
In some embodiments, the positive electrode film layer further optionally includes a binder. As an example, the binder may include at least one of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), a vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, a vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, a tetrafluoroethylene-hexafluoropropylene copolymer, and a fluoroacrylate resin.
In some embodiments, the positive electrode film layer further optionally includes a conductive agent. As an example, the conductive agent may include at least one of superconducting carbon, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.
In some embodiments, the positive electrode sheet may be prepared by dispersing the above-described components for preparing a positive electrode sheet, such as a positive electrode active material, a conductive agent, a binder, and any other components, in a solvent (e.g., N-methylpyrrolidone) to form a positive electrode slurry, coating the positive electrode slurry on a positive electrode current collector, and performing processes such as drying, cold pressing, and the like to obtain the positive electrode sheet.
[ Negative electrode sheet ]
The negative electrode plate comprises a negative electrode current collector and a negative electrode film layer arranged on at least one surface of the negative electrode current collector, wherein the negative electrode film layer comprises a negative electrode active material.
As an example, the anode current collector has two surfaces opposing in its own thickness direction, and the anode film layer is provided on either one or both of the two surfaces opposing the anode current collector.
In some embodiments, the negative electrode current collector may employ a metal foil or a composite current collector. For example, as the metal foil, copper foil may be used. The composite current collector may include a polymeric material base layer and a metal layer formed on at least one surface of the polymeric material base material. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel alloy, titanium alloy, silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), polyethylene (PE), etc.).
In some embodiments, the anode active material may employ an anode active material for a battery, which is well known in the art. As an example, the anode active material may include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based material, tin-based material, lithium titanate, and the like. The silicon-based material may be at least one selected from elemental silicon, silicon oxygen compounds, silicon carbon composites, silicon nitrogen composites, and silicon alloys. The tin-based material may be at least one selected from elemental tin, tin oxide, and tin alloys. However, the present application is not limited to these materials, and other conventional materials that can be used as a battery anode active material may be used. These negative electrode active materials may be used alone or in combination of two or more.
In some embodiments, the negative electrode film layer further optionally includes a binder. The binder may be at least one selected from Styrene Butadiene Rubber (SBR), polyacrylic acid (PAA), sodium Polyacrylate (PAAs), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium Alginate (SA), polymethacrylic acid (PMAA), and carboxymethyl chitosan (CMCS).
In some embodiments, the negative electrode film layer further optionally includes a conductive agent. The conductive agent is at least one selected from superconducting carbon, acetylene black, carbon black, ketjen black, carbon dots, carbon nanotubes, graphene and carbon nanofibers.
In some embodiments, the negative electrode film layer may optionally further include other adjuvants, such as thickening agents (e.g., sodium carboxymethyl cellulose (CMC-Na)), and the like.
In some embodiments, the negative electrode tab may be prepared by dispersing the above components for preparing the negative electrode tab, such as the negative electrode active material, the conductive agent, the binder, and any other components, in a solvent (e.g., deionized water) to form a negative electrode slurry, coating the negative electrode slurry on a negative electrode current collector, and performing processes such as drying, cold pressing, and the like to obtain the negative electrode tab.
[ Electrolyte ]
The electrolyte plays a role in ion conduction between the positive electrode plate and the negative electrode plate. The application is not particularly limited in the kind of electrolyte, and may be selected according to the need. For example, the electrolyte may be liquid, gel, or all solid.
In some embodiments, the electrolyte is an electrolyte. The electrolyte includes an electrolyte salt and a solvent.
In some embodiments, the electrolyte salt may be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis-fluorosulfonyl imide, lithium bis-trifluoromethanesulfonyl imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalato borate, lithium difluorodioxaato phosphate, and lithium tetrafluorooxalato phosphate.
In some embodiments, the solvent may be selected from at least one of ethylene carbonate, propylene carbonate, methylethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methylpropyl carbonate, ethylpropyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1, 4-butyrolactone, sulfolane, dimethyl sulfone, methyl sulfone, and diethyl sulfone.
In some embodiments, the electrolyte further optionally includes an additive. For example, the additives may include negative electrode film-forming additives, positive electrode film-forming additives, and may also include additives capable of improving certain properties of the battery, such as additives that improve the overcharge performance of the battery, additives that improve the high or low temperature performance of the battery, and the like.
[ Isolation Membrane ]
In some embodiments, a separator is further included in the secondary battery. The type of the separator is not particularly limited, and any known porous separator having good chemical stability and mechanical stability can be used.
In some embodiments, the material of the isolating film may be at least one selected from glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride. The separator may be a single-layer film or a multilayer composite film, and is not particularly limited. When the separator is a multilayer composite film, the materials of the respective layers may be the same or different, and are not particularly limited.
In some embodiments, the positive electrode tab, the negative electrode tab, and the separator may be manufactured into an electrode assembly through a winding process or a lamination process.
In some embodiments, the secondary battery may include an outer package. The outer package may be used to encapsulate the electrode assembly and electrolyte described above.
In some embodiments, the outer package of the secondary battery may be a hard case, such as a hard plastic case, an aluminum case, a steel case, or the like. The exterior package of the secondary battery may also be a pouch type pouch, for example. The material of the flexible bag may be plastic, and examples of the plastic include polypropylene, polybutylene terephthalate, and polybutylene succinate.
The shape of the secondary battery is not particularly limited in the present application, and may be cylindrical, square, or any other shape. For example, fig. 5 is a secondary battery 5 of a square structure as one example.
In some embodiments, referring to fig. 6, the outer package may include a housing 51 and a cover 53. The housing 51 may include a bottom plate and a side plate connected to the bottom plate, where the bottom plate and the side plate enclose a receiving chamber. The housing 51 has an opening communicating with the accommodation chamber, and the cover plate 53 can be provided to cover the opening to close the accommodation chamber. The positive electrode tab, the negative electrode tab, and the separator may be formed into the electrode assembly 52 through a winding process or a lamination process. The electrode assembly 52 is enclosed in the accommodating chamber. The electrolyte is impregnated in the electrode assembly 52. The number of electrode assemblies 52 included in the secondary battery 5 may be one or more, and those skilled in the art may select according to specific practical requirements.
In some embodiments, the secondary batteries may be assembled into a battery module, and the number of secondary batteries included in the battery module may be one or more, and the specific number may be selected by one skilled in the art according to the application and capacity of the battery module.
Fig. 7 is a battery module 4 as an example. Referring to fig. 7, in the battery module 4, a plurality of secondary batteries 5 may be sequentially arranged in the longitudinal direction of the battery module 4. Of course, the arrangement may be performed in any other way. The plurality of secondary batteries 5 may be further fixed by fasteners.
Alternatively, the battery module 4 may further include a case having an accommodating space in which the plurality of secondary batteries 5 are accommodated.
In some embodiments, the above battery modules may be further assembled into a battery pack, and the number of battery modules included in the battery pack may be one or more, and a specific number may be selected by those skilled in the art according to the application and capacity of the battery pack.
Fig. 8 and 9 are battery packs 1 as an example. Referring to fig. 8 and 9, a battery case and a plurality of battery modules 4 disposed in the battery case may be included in the battery pack 1. The battery box includes an upper box body 2 and a lower box body 3, and the upper box body 2 can be covered on the lower box body 3 and forms a closed space for accommodating the battery module 4. The plurality of battery modules 4 may be arranged in the battery box in any manner.
In addition, the application also provides an electric device which comprises at least one of the secondary battery, the battery module or the battery pack. The secondary battery, the battery module, or the battery pack may be used as a power source of the power consumption device, and may also be used as an energy storage unit of the power consumption device. The power utilization device may include mobile devices (e.g., cell phones, notebook computers, etc.), electric vehicles (e.g., electric-only vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc., but is not limited thereto.
As the electricity consumption device, a secondary battery, a battery module, or a battery pack may be selected according to the use requirements thereof.
Fig. 10 is an electric device as an example. The electric device is a pure electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle or the like. In order to meet the high power and high energy density requirements of the secondary battery by the power consumption device, a battery pack or a battery module may be employed.
As another example, the device may be a cell phone, tablet computer, notebook computer, or the like. The device is generally required to be light and thin, and a secondary battery can be used as a power source.
Examples
Hereinafter, embodiments of the present application are described. The following examples are illustrative only and are not to be construed as limiting the application. The examples are not to be construed as limiting the specific techniques or conditions described in the literature in this field or as per the specifications of the product. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.
Example 1
The ternary positive electrode active material of example 1 was obtained by the following procedure.
Adding water into nickel sulfate, cobalt sulfate and manganese sulfate according to a molar ratio of 6:2:2 to prepare a mixed salt solution with the total concentration of nickel, cobalt and manganese being 2mol/L as a first mixed solution, and adding water into boric acid and zirconium oxychloride to prepare a solution with the concentration of 0.2mol/L as a second solution and a third solution respectively.
Continuously adding the first mixed solution, the second solution, 8mol/L sodium hydroxide solution and 25% ammonia water into a reaction kettle to perform a first-stage growth reaction. In the reaction process, the reaction temperature in the reaction kettle is controlled to be 50 ℃, the feeding speed is controlled to enable the pH value of the solution to be 11, the ammonia content to be 7g/L, and the molar ratio of boric acid to the total content of nickel, cobalt and manganese to be 1:10. And (3) sampling and monitoring the particle size of product particles in the reaction kettle from the discharge port while carrying out the reaction, and after the reaction is carried out until the target particle size D50 is 8 mu m, switching the second solution feed port into the third solution feed port to carry out the second-stage growth reaction. The reaction conditions, pH and ammonia content in the reaction vessel remained the same as in the first stage. And controlling the feeding speed of the third solution to enable the molar ratio of the zirconium oxychloride to the total content of nickel, cobalt and manganese to be 1:500, sampling and monitoring the particle size of product particles in the reaction kettle from a discharge hole, and ending the reaction after the reaction reaches the target particle size D50 of 10 mu m.
And aging the precipitate for 12 hours, washing with deionized water, performing solid-liquid separation, and drying the solid to obtain nickel-cobalt-manganese precursor particles with the core part doped with boron and the shell part doped with zirconium.
Mixing nickel cobalt manganese precursor particles with lithium hydroxide according to the ratio of the total molar quantity of nickel cobalt manganese to the molar quantity of lithium of 1:1.05, and calcining for 10 hours at 750 ℃ in an oxygen atmosphere to obtain the nickel cobalt manganese ternary positive electrode material lithium nickel cobalt manganese oxide with the core part doped with boron and the shell part doped with zirconium and a core-shell structure.
Examples 2 to 6
Except that the feed rate was controlled so that the molar ratios of boric acid and nickel cobalt manganese ions were respectively as shown in table 1 during the first-stage growth reaction, the nickel cobalt manganese ternary cathode materials lithium nickel cobalt manganese oxides with core-shell structures of examples 2 to 6 were prepared under the same conditions as in example 1.
Examples 7 to 10
Except that the feed rate was controlled so that the molar ratios of zirconium oxychloride and nickel cobalt manganese ions were each as shown in table 1 during the second-stage growth reaction, the same conditions as in example 4 were followed to prepare the nickel cobalt manganese ternary cathode materials lithium nickel cobalt manganese oxides with core-shell structures of examples 7 to 10.
Examples 11 to 12
Except that the charging reaction time was controlled to control the target particle size of the first stage and the target particle size of the second stage to be the particle size values shown in table 1, respectively, in the growth reaction process of the first stage and the second stage, the nickel-cobalt-manganese ternary cathode materials lithium-nickel-cobalt-manganese oxides having core-shell structures of examples 11 to 12 were prepared under the same conditions as in example 4.
Examples 13 to 14
Except that zirconium oxychloride in the third solution is respectively changed into titanic acid and sodium metaaluminate, and the feeding speed in the second-stage growth reaction process is controlled so that the molar ratio of titanium or aluminum to the total content of nickel, cobalt and manganese is 1:500, the other conditions are the same as those in example 4, and the nickel, cobalt and manganese ternary cathode materials lithium, cobalt and manganese oxides with core-shell structures of examples 13-14 are prepared.
Examples 15 to 16
Except that boric acid in the second solution was changed to sodium dihydrogen phosphate and the feeding rate during the growth reaction in the first stage was controlled so that the molar ratio of boron to the total content of nickel, cobalt and manganese was 1:500, respectively, the nickel, cobalt and manganese ternary cathode material lithium, nickel, cobalt and manganese oxide with a core-shell structure of example 15 was prepared under the same conditions as in example 13.
Except that boric acid in the second solution was changed to sodium dihydrogen phosphate and the feeding rate during the growth reaction in the first stage was controlled so that the molar ratio of boron to the total content of nickel, cobalt and manganese was 1:500, respectively, the nickel, cobalt and manganese ternary cathode material lithium, nickel, cobalt and manganese oxide with a core-shell structure of example 16 was prepared under the same conditions as in example 14.
Examples 17 to 20
The nickel cobalt manganese ternary cathode materials lithium nickel cobalt manganese oxides with core-shell structures of examples 17 to 20 were prepared in the same manner as in example 15, except that the titanic acid in the third solution was replaced with a mixture of zirconium oxychloride and titanic acid in a molar ratio of 1:1, a mixture of zirconium oxychloride and sodium metaaluminate in a molar ratio of 1:1, a mixture of titanic acid and sodium metaaluminate in a molar ratio of 1:1, and a mixture of zirconium oxychloride, titanic acid and sodium metaaluminate in a molar ratio of 1:1, respectively, and the feed rate during the second stage growth reaction was controlled so that the molar ratio of the total content of zirconium, titanium or aluminum to the total content of nickel cobalt manganese was 1:500, respectively.
Comparative example 1
Adding water into nickel sulfate, cobalt sulfate and manganese sulfate according to a molar ratio of 6:2:2 to prepare a mixed salt solution with the total concentration of nickel, cobalt and manganese being 2mol/L, and continuously adding the mixed solution, a sodium hydroxide solution with the concentration of 8mol/L and ammonia water with the mass fraction of 25% into a reaction kettle to perform a growth reaction. In the reaction process, the reaction temperature in the reaction kettle is controlled to be 50 ℃, and the feeding speed is controlled to ensure that the pH value of the solution is 11, and the ammonia content is 7g/L. The particle size of the product particles in the reaction vessel was monitored by sampling from the outlet while the reaction was carried out, and after the reaction was completed until the target particle size D50 was 10. Mu.m. And aging the precipitate for 12 hours, washing with deionized water, performing solid-liquid separation, and drying the solid to obtain nickel-cobalt-manganese precursor particles. The nickel cobalt manganese precursor particles and lithium hydroxide are mixed according to a molar ratio of 1:1.05, and are calcined for 10 hours at 750 ℃ in an oxygen atmosphere, so that the lithium nickel cobalt manganese oxide of the non-doped nickel cobalt manganese ternary cathode material of the comparative example 1 is obtained.
Comparative example 2
Adding water into nickel sulfate, cobalt sulfate and manganese sulfate according to a molar ratio of 6:2:2 to prepare a mixed salt solution with the total concentration of nickel, cobalt and manganese being 2mol/L, and adding water into zirconium oxychloride to prepare a solution with the concentration of 0.2mol/L as a zirconium solution. Continuously adding the mixed salt solution, 8mol/L sodium hydroxide solution and 25 mass percent ammonia water into a reaction kettle to perform a growth reaction. In the reaction process, the reaction temperature in the reaction kettle is controlled to be 50 ℃, and the feeding speed is controlled to ensure that the pH value of the solution is 11, and the ammonia content is 7g/L. Sampling and monitoring the particle size of product particles in the reaction kettle from a discharge hole while carrying out the reaction, adding a zirconium solution feed inlet to a feed inlet after the reaction is carried out until the target particle size D50 is 8 mu m, continuously adding a zirconium solution into a reaction system, controlling the feed rate of the zirconium solution so that the molar ratio of zirconium oxychloride to the total content of nickel cobalt manganese is 1:500, continuously carrying out the reaction until the target particle size D50 is 10 mu m, and ending the reaction. And aging the precipitate for 12 hours, washing with deionized water, performing solid-liquid separation, and drying the solid to obtain nickel-cobalt-manganese precursor particles. The nickel cobalt manganese precursor particles and lithium hydroxide are mixed according to a molar ratio of 1:1.05, and are calcined for 10 hours at 750 ℃ in an oxygen atmosphere, so that the lithium nickel cobalt manganese oxide of the nickel cobalt manganese ternary anode material with the zirconium doped shell part of the comparative example 2 is obtained.
Comparative example 3
The same conditions as in example 4 were followed except that the feed rate was controlled so that the molar ratio of boric acid to the total content of nickel cobalt manganese was 1:10000 during the first-stage growth reaction, to obtain a nickel cobalt manganese ternary positive electrode material lithium nickel cobalt manganese oxide of comparative example 3 doped in both inner and outer stages.
Comparative example 4
The one-stage doped lithium nickel cobalt manganese ternary cathode material of comparative example 4 was obtained in the same manner as example 4 except that in the preparation of the nickel cobalt manganese precursor particles, the first-stage growth reaction was continued until the target particle diameter D50 was 10 μm, and then the reaction was directly ended and the second-stage growth reaction was not performed.
Comparative example 5
A nickel-cobalt-manganese ternary positive electrode material lithium-nickel-cobalt-manganese oxide of comparative example 5 doped only in the first stage was obtained in the same manner as in example 4, except that the second solution feed port was directly removed without switching to the third solution feed port in the process of switching from the first-stage growth to the second-stage growth.
In each experimental example, the average particle diameter D50 of precursor particles in a reaction system is determined by using a Markov 2000 (MasterSizer 2000) laser particle sizer according to the following procedures that a proper amount of a sample to be measured is taken, 20ml of deionized water is added, the sample is completely dispersed by ultrasonic waves, the dispersed sample is dripped into a sample injector of the particle sizer, which is filled with the deionized water, to be adjusted to have 10-20% of shading degree, and the sample is determined according to the GB/T19077-2016/ISO 13320:2009 standard.
The experimental parameters related to the positive electrode material manufacturing process of examples 1 to 20 and comparative examples 1 to 5 are shown in table 1 below.
Morphology observation of nickel cobalt manganese precursor particles and nickel cobalt manganese ternary positive electrode material
The nickel cobalt manganese precursor particles of example 4 were ground and then observed for internal morphology by Scanning Electron Microscopy (SEM) (ZEISS sigma 300) (fig. 2), and it was found that core portions composed of radially elongated grown primary particles arranged in an emission-like manner were formed inside the particles, and a layer of randomly grown shell layers was wrapped around the shell portions, and the shell layers were dense, neat and seamless. The nickel cobalt manganese precursor particles of comparative example 1 were observed for their internal morphology by Scanning Electron Microscopy (SEM) (fig. 3), and it was found that the particles were composed entirely of randomly grown primary particles therein. Further, the nickel cobalt manganese precursor particles of comparative example 4 were observed for their internal morphology by Scanning Electron Microscopy (SEM) (fig. 4), and it was found that the particles were entirely composed of radially elongated primary particles grown in an emission form, the surfaces thereof were in a loose form, and gaps extending inward from the surfaces along the growth direction of the elongated primary particles were clearly observed. From this, it is apparent that in example 4 of the present invention, the core portion composed of radially elongated primary particles grown in an radial shape can be formed inside by the growth reaction in the first stage, and the shell portion composed of randomly grown primary particles can be wrapped outside by the growth reaction in the second stage, so that dense and stable nickel-cobalt-manganese precursor secondary particles can be obtained by the core-shell structure.
The nickel-cobalt-manganese ternary cathode materials obtained in the above examples and comparative examples were each observed by a Scanning Electron Microscope (SEM) (ZEISS sigma 300) for the presence or absence of radially grown nuclei therein, and for the disordered growth of the outer layer thereof, and the results are shown in table 2.
In addition, the positive electrode active materials obtained in examples 1 to 20 and comparative examples 1 to 5 described above were each prepared into secondary batteries as shown below, and performance tests were performed. The test results are shown in table 2 below.
Preparation and performance test of secondary battery
1. Preparation of positive electrode plate
The preparation method comprises the steps of taking the prepared composite material as an anode active material, dissolving the anode active material, conductive agent carbon black and binder polyvinylidene fluoride (PVDF) in a weight ratio of 97:2:1 in solvent N-methyl pyrrolidone (NMP), fully stirring and uniformly mixing to obtain anode slurry, uniformly coating the anode slurry on an aluminum foil current collector, drying, cold pressing and cutting to obtain anode plates, and weighing and calculating the mass m (g) of the fluorine-coated anode material on each anode plate after drying.
2. Preparation of negative electrode plate
The preparation method comprises the steps of dissolving active substances of artificial graphite, conductive agent carbon black, binder Styrene Butadiene Rubber (SBR) and thickener sodium carboxymethylcellulose (CMC) in a weight ratio of 96.2:0.8:0.8:1.2 in deionized water, uniformly mixing to prepare negative electrode slurry, uniformly coating the negative electrode slurry on a negative electrode current collector copper foil one or more times, drying, cold pressing and cutting to obtain a negative electrode plate.
3. Preparation of electrolyte
In an argon atmosphere glove box (H 2O<0.1ppm,O2 <0.1 ppm), uniformly mixing an organic solvent of Ethylene Carbonate (EC)/ethylmethyl carbonate (EMC) according to a volume ratio of 3/7, adding 12.5 mass% of LiPF6 lithium salt to dissolve in the organic solvent, and uniformly stirring to obtain an electrolyte.
4. Isolation film
A polypropylene film was used as a separator.
5. Preparation of secondary battery
Sequentially stacking the positive electrode plate, the isolating film and the negative electrode plate, enabling the isolating film to be positioned between the positive electrode plate and the negative electrode plate, winding to obtain a bare cell, welding a tab for the bare cell, loading the bare cell into an aluminum shell, baking at 100 ℃ for dewatering, injecting electrolyte, and sealing to obtain the uncharged battery. And the uncharged battery is subjected to the procedures of standing, hot and cold pressing, formation, shaping, capacity testing and the like in sequence, so that a secondary battery product is obtained.
Specific capacity test
The secondary battery was charged to 4.2V at a constant current of 1/3C, then charged to 0.05C at a constant voltage of 4.2V, left for 5min, then discharged to 2.8V at 1/3C, and the resulting capacity was designated as initial capacity C0 (mAh). Specific capacity=c0/(m×97%), where m is the coating mass (g) of the positive electrode active material in each battery.
Battery capacity retention test
The secondary battery was charged to 4.2V at a constant current of 1/3C, then charged to 0.05C at a constant voltage of 4.2V, left for 5min, and then discharged to 2.8V at 1/3C, and the resulting capacity was recorded as an initial capacity C0. The above procedure was repeated for the same battery, and the discharge capacity Cn of the battery after the nth cycle was recorded, and the battery capacity retention pn=cn/c0×100% after each cycle was recorded as the test result in table 2.
Table 2:
From the above results, it was found that the particles of the nickel-cobalt-manganese ternary cathode material obtained in all examples subjected to two-stage doping had a core-shell structure having a core portion consisting of radially aligned radially grown primary particles inside and a shell portion grown out of order outside. Whereas comparative example 1, which was not subjected to any doping, did not form particles having a core-shell structure. In comparative examples 2 and 3, the first-stage boron/phosphorus doping was not performed or the doping concentration was too low to form a core portion composed of primary particles radially grown inside. The particles of comparative example 4 did not grow a shell portion composed of randomly grown primary particles. The shell portion in comparative example 5 was composed of undoped nickel cobalt manganese ternary cathode material, which was also composed of randomly grown primary particles.
As is apparent from the comparison of the performances of the secondary batteries of comparative examples 1 and 2, the capacity retention rate of the secondary battery can be improved by Zr doping of the case portion, since Zr doping can improve the corrosion resistance of the positive electrode material, thereby improving the stability in use thereof. In addition, as is clear from a comparison of comparative example 5 and comparative example 1, the specific capacity of the secondary battery can be improved by the boron doping of the core portion, since the boron doping makes the core portion composed of primary particles radially grown, the migration path during the lithium ion migration is shortened, the lithium ion migration efficiency is improved, and the specific capacity of the secondary battery is improved. As is clear from a comparison between examples 1 to 20 and comparative examples 1 to 5, examples 1 to 20, which are formed with a core-shell structure in which boron and/or phosphorus are internally doped and any one selected from zirconium, titanium and aluminum is externally doped, have both improved specific capacity and capacity retention.
The present application is not limited to the above embodiment. The above embodiments are merely examples, and embodiments having substantially the same configuration and the same effects as those of the technical idea within the scope of the present application are included in the technical scope of the present application. Further, various modifications that can be made to the embodiments and other modes of combining some of the constituent elements in the embodiments, which are conceivable to those skilled in the art, are also included in the scope of the present application within the scope not departing from the gist of the present application.
Claims (20)
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210269050.4A CN115832268B (en) | 2022-03-18 | 2022-03-18 | Ternary positive electrode material, method for producing the same, and secondary battery using the same |
| PCT/CN2023/078720 WO2023174050A1 (en) | 2022-03-18 | 2023-02-28 | Ternary positive electrode material and manufacturing method therefor, and secondary battery using ternary positive electrode material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210269050.4A CN115832268B (en) | 2022-03-18 | 2022-03-18 | Ternary positive electrode material, method for producing the same, and secondary battery using the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115832268A CN115832268A (en) | 2023-03-21 |
| CN115832268B true CN115832268B (en) | 2025-03-18 |
Family
ID=85522437
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210269050.4A Active CN115832268B (en) | 2022-03-18 | 2022-03-18 | Ternary positive electrode material, method for producing the same, and secondary battery using the same |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN115832268B (en) |
| WO (1) | WO2023174050A1 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116655002B (en) * | 2023-06-15 | 2025-03-07 | 合肥国轩高科动力能源有限公司 | Doped modified nickel cobalt lithium manganate monocrystal positive electrode material and preparation method thereof |
| CN117254118A (en) * | 2023-11-17 | 2023-12-19 | 宁德时代新能源科技股份有限公司 | Secondary battery and electricity utilization device |
| CN119340384A (en) * | 2024-12-09 | 2025-01-21 | 广州汽车集团股份有限公司 | A positive electrode material and preparation method thereof, a positive electrode sheet, a battery and an electric device |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107534140A (en) * | 2015-04-30 | 2018-01-02 | 株式会社Lg化学 | Cathode active material for secondary battery, its preparation method and the secondary cell for including the positive electrode active materials |
| CN111634958A (en) * | 2020-06-02 | 2020-09-08 | 格林美股份有限公司 | Precursor for lithium battery, positive electrode material for lithium battery and preparation method thereof |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3723175A4 (en) * | 2018-01-12 | 2022-01-12 | Battery Solution | Positive electrode active material, method for preparing same, and lithium secondary battery comprising same |
| CN108793268B (en) * | 2018-06-19 | 2019-07-16 | 中南大学 | Core-shell structure gradient nickel-cobalt-manganese ternary cathode material precursor and preparation method thereof |
| CN111916687B (en) * | 2019-05-09 | 2023-10-27 | 深圳市贝特瑞纳米科技有限公司 | Positive electrode material, preparation method thereof and lithium ion battery |
| JP7451728B2 (en) * | 2020-01-29 | 2024-03-18 | エルジー・ケム・リミテッド | Positive electrode active material precursor for secondary batteries, positive electrode active material, and lithium secondary batteries containing the same |
| KR20210118644A (en) * | 2020-03-23 | 2021-10-01 | 주식회사 엘지화학 | Positive electrode active material for lithium secondary battery, preparing method of the same, positive electrode and lithium secondary battery including the same |
| CN113130877B (en) * | 2021-06-18 | 2021-09-24 | 长沙理工大学 | Polycrystalline positive electrode material synchronously modified by doping and dip coating, and solid-phase preparation method and application thereof |
-
2022
- 2022-03-18 CN CN202210269050.4A patent/CN115832268B/en active Active
-
2023
- 2023-02-28 WO PCT/CN2023/078720 patent/WO2023174050A1/en active Application Filing
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107534140A (en) * | 2015-04-30 | 2018-01-02 | 株式会社Lg化学 | Cathode active material for secondary battery, its preparation method and the secondary cell for including the positive electrode active materials |
| CN111634958A (en) * | 2020-06-02 | 2020-09-08 | 格林美股份有限公司 | Precursor for lithium battery, positive electrode material for lithium battery and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2023174050A1 (en) | 2023-09-21 |
| CN115832268A (en) | 2023-03-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP7534425B2 (en) | Positive electrode active material, its manufacturing method, secondary battery, battery module, battery pack and device | |
| CN115832268B (en) | Ternary positive electrode material, method for producing the same, and secondary battery using the same | |
| CN115668535B (en) | Lithium-ion secondary battery, battery module, battery pack, and power-consuming device | |
| EP4386899A1 (en) | Negative electrode active material and preparation method therefor, secondary battery comprising same, and electric device | |
| US20220399540A1 (en) | Composite positive electrode material and preparation method thereof, secondary battery, battery group including secondary battery, and electric apparatus including secondary battery | |
| CN115810863B (en) | Separator, method for producing separator, secondary battery, battery module, battery pack, and electric device | |
| CN118645677B (en) | Lithium ion battery, lithium supplementing agent, positive pole piece and power utilization device | |
| CN117088352A (en) | Preparation method of lithium iron phosphate, positive electrode active material, positive electrode plate, battery and electricity utilization device | |
| CN117916912A (en) | Positive electrode active material and preparation method thereof, secondary battery, battery module, battery pack and electric device | |
| CN116435505A (en) | Silicon anode material, and secondary battery, battery module, battery pack and power utilization device comprising silicon anode material | |
| CN116941084A (en) | Secondary battery | |
| CN117342631B (en) | Ternary precursor, preparation method thereof, secondary battery and power utilization device | |
| US20250011172A1 (en) | Lithium nickel manganese-containing composite oxide, method for preparation thereof, positive electrode plate, secondary battery and electrical device | |
| CN219591429U (en) | Cathode pole piece, electrode assembly, battery cell, battery and electricity utilization device | |
| CN117080415B (en) | Positive electrode active material composition, positive electrode plate, battery and electric equipment | |
| CN115832285B (en) | Positive electrode material, preparation method thereof, positive electrode plate, secondary battery, battery module, battery pack and power utilization device | |
| CN115842122B (en) | Lithium titanate coated graphite composite material, preparation method thereof, and secondary battery, battery module, battery pack, and electrical device containing the same | |
| KR102784786B1 (en) | Cathode active material, secondary battery, battery module, battery pack and electrical device | |
| US20230318140A1 (en) | Separator and related secondary battery, battery module, battery pack and power consumption apparatus | |
| CN119852331A (en) | Positive electrode material for lithium secondary battery, preparation method of positive electrode material, positive electrode plate, secondary battery, use method of positive electrode plate and use method of secondary battery | |
| CN118525386A (en) | Composite positive electrode material, preparation method thereof, secondary battery, battery module, battery pack and power utilization device | |
| WO2024243957A1 (en) | Electrode material and preparation method therefor, battery, and electric device | |
| JP2024528160A (en) | Negative electrode plate and its manufacturing method, secondary battery, battery module, battery pack and power consumption device | |
| CN119522491A (en) | Positive electrode active material and preparation method thereof, positive electrode sheet, battery and electric device | |
| WO2024243906A1 (en) | Positive electrode active material and preparation method therefor, and positive electrode sheet, battery and electric device comprising same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |