CN119231096B - Super-amphiphilic coating capable of conducting lithium ions, preparation method and application thereof, diaphragm, pole piece and lithium-ion battery - Google Patents
Super-amphiphilic coating capable of conducting lithium ions, preparation method and application thereof, diaphragm, pole piece and lithium-ion batteryInfo
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- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
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- H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
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- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
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Abstract
本发明提供了一种可传导锂离子的超双亲涂层及其制备方法和应用、隔膜、极片和锂离子电池，涉及电池技术领域。本发明提供的可传导锂离子的超双亲涂层，包括双亲材料和锂离子导体纳米材料；双亲材料包覆在锂离子导体纳米材料的表面。其中，锂离子导体纳米材料提供良好的锂离子传导性能，双亲材料包覆层以及锂离子导体纳米材料构成微纳米结构，能够提供超亲油和超亲水能力。因此本发明提供的超双亲涂层可用作锂离子电池的隔膜和集流体的涂层，其极强的亲电解液能力，能够加速电解液的回吸，提升电芯的吸液能力，同时不影响电化学性能发挥；而且该超双亲涂层的微纳米结构和聚合物成分具备较好的保液能力，有助于缓解膨胀过程中电解液的挤出。
The present invention provides a super-amphiphilic coating that can conduct lithium ions, a preparation method and application thereof, a diaphragm, an electrode and a lithium-ion battery, and relates to the field of battery technology. The super-amphiphilic coating that can conduct lithium ions provided by the present invention comprises an amphiphilic material and a lithium-ion conductor nanomaterial; the amphiphilic material is coated on the surface of the lithium-ion conductor nanomaterial. Among them, the lithium-ion conductor nanomaterial provides good lithium-ion conductivity, and the amphiphilic material coating layer and the lithium-ion conductor nanomaterial constitute a micro-nanostructure that can provide super-oleophilic and super-hydrophilic capabilities. Therefore, the super-amphiphilic coating provided by the present invention can be used as a coating for the diaphragm and current collector of a lithium-ion battery. Its extremely strong electrolyte affinity can accelerate the back absorption of the electrolyte and improve the liquid absorption capacity of the battery core without affecting the electrochemical performance. Moreover, the micro-nanostructure and polymer components of the super-amphiphilic coating have good liquid retention capabilities, which help to alleviate the extrusion of the electrolyte during the expansion process.
Description
Technical Field
The invention relates to the technical field of batteries, in particular to a super-amphiphilic coating capable of conducting lithium ions, a preparation method and application thereof, a diaphragm, a pole piece and a lithium ion battery.
Background
With the development of technology, lithium ion batteries are widely used in various fields of consumer electronics, power, energy storage and the like. Because of the higher requirements of application scenes and the increasing trend of market competition, the lithium ion battery with high energy density and high power density and high safety and long service life becomes the development focus of various large battery manufacturing enterprises.
However, in the lithium ion battery, the electrode material is continuously expanded and contracted in the charge and discharge process, and the electrolyte between the electrode sheet and the electrode sheet is extruded and flows back into the recovered pores after the volume of the electrode material is retracted. In the process, electrolyte backflow non-uniformity and local lean solution can occur, lithium precipitation is generated at a liquid shortage position due to insufficient lithium ion conduction capability, so that unpredictable circulation 'water jump' of the battery cell occurs, and the cycle life of the battery cell is seriously influenced.
The literature studies have suggested that the electrolyte first wets the separator and then diffuses to the electrode, and that if insufficient wetting in the electrode occurs, a non-wetting phase is found near the electrode/current collector interface and that wetting is relatively adequate on the separator side. Based on the above, it is important to improve the ability of the pole piece and the diaphragm to suck back the electrolyte, while improving the wettability of the pole piece and the diaphragm with the electrolyte is a key to improve the liquid absorbing ability. Currently, solvents commonly used in commercial lithium ion battery electrolytes include Ethylene Carbonate (EC), propylene Carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), and methyl ethyl carbonate (EMC), etc., and commercial electrolytes are mixed with various solvents, so it is necessary to develop a solution suitable for improving wettability of various electrolytes.
In view of this, the present invention has been made.
Disclosure of Invention
The first object of the present invention is to provide a super-amphiphilic coating capable of conducting lithium ions, so as to solve the above technical problems.
The second object of the invention is to provide a method for preparing the super-amphiphilic coating capable of conducting lithium ions.
A third object of the present invention is to provide an application of the above-mentioned super-amphiphilic coating capable of conducting lithium ions in a battery.
A fourth object of the present invention is to provide a separator.
A fifth object of the present invention is to provide a pole piece.
A sixth object of the present invention is to provide a lithium ion battery.
In order to achieve the above object, the following technical scheme is adopted:
In a first aspect, the invention provides a super-amphiphilic coating capable of conducting lithium ions, which comprises an amphiphilic material and a lithium ion conductor nanomaterial, wherein the amphiphilic material is coated on the surface of the lithium ion conductor nanomaterial;
The amphiphilic material comprises at least one of propoxyl glycerol triglycidyl ether polymer, polyvinylpyrrolidone, polydopamine, polyethylene glycol-polytetramethyl ether glycol copolymer or polyethylene glycol-polydimethylsiloxane copolymer;
The lithium ion conductor nanomaterial comprises at least one of NASICON type oxide solid electrolyte, LISICON type oxide electrolyte, garnet type oxide solid electrolyte, perovskite type oxide solid electrolyte or Anti-Perovskite type oxide solid electrolyte;
the particle size of the lithium ion conductor nano material is 10-200nm.
As a further technical scheme, the mass ratio of the amphiphilic material to the lithium ion conductor nano material is 0.01:1-10:1.
As a further technical scheme, the static contact angle of the aqueous solvent of the super-amphiphilic coating is less than 5 degrees, and the static contact angle of the oil solvent is less than 5 degrees.
As a further technical scheme, the NASICON-type oxide solid-state electrolyte comprises Li 1.4Al0.4Ti1.6(PO4)3 or Li 1.5Al0.5Ge1.5(PO4)3;
the LISICON type oxide electrolyte comprises gamma-Li 3PO4;
the Garnet-type oxide solid electrolyte comprises Li 7La3Zr2O12 or Li 5La3Ta2O12;
The Perovskite type oxide solid state electrolyte comprises Li 0.5La0.5TiO3;
The Anti-perovskie oxide solid state electrolyte comprises Li 3 OCl.
In a second aspect, the invention provides a preparation method of the super-amphiphilic coating capable of conducting lithium ions, which comprises the following steps:
Mixing the amphiphilic material or a precursor thereof, the lithium ion conductor nano material and a solvent to form a dispersion liquid, then coating the dispersion liquid, and drying to prepare the super-amphiphilic coating capable of conducting lithium ions;
the solvent comprises at least one of ethanol, deionized water, n-hexane, tetrahydrofuran THF, heptane, isopropanol, carbon trichloride or carbon tetrachloride.
As a further technical scheme, the mass ratio of the lithium ion conductor nano material in the dispersion liquid is 0.1% -10%.
In a third aspect, the invention provides the use of a lithium ion-conductive superamphiphilic coating as described above in a battery.
In a fourth aspect, the present invention provides a separator comprising a base film coated on a surface thereof with the lithium ion-conductive super-amphiphilic coating.
In a fifth aspect, the present invention provides a pole piece comprising a current collector, the surface of which is coated with the lithium ion-conductive super-amphiphilic coating.
In a sixth aspect, the present invention provides a lithium ion battery, including the separator and/or the pole piece.
Compared with the prior art, the invention has the following beneficial effects:
The super-amphiphilic coating capable of conducting lithium ions, provided by the invention, has the advantages that the lithium ion conductor nano material provides good lithium ion conduction performance, the amphiphilic material coating layer and the lithium ion conductor nano material form a micro-nano structure, and super-oleophilic and super-hydrophilic capabilities can be provided. The lithium ion-conductive super-amphiphilic coating provided by the invention can be used as a coating of a diaphragm and a current collector of a lithium ion battery, has extremely strong electrolyte-philic capability, can accelerate the back suction of electrolyte, improves the liquid absorption capability of a battery core, does not affect the exertion of electrochemical performance, has better liquid retention capability on a micro-nano structure and polymer components, is favorable for relieving the extrusion of electrolyte in an expansion process, and can effectively relieve lithium precipitation caused by the shortage of the middle part of the battery core in the circulation process and prolong the circulation cycle life of the battery core.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present invention, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic structural diagram of a lithium ion-conductive super-amphiphilic coating.
The icon is 1-lithium ion conductor nano material, 2-amphiphilic material and 10-super-amphiphilic coating capable of conducting lithium ions.
Detailed Description
Embodiments of the present invention will be described in detail below with reference to embodiments and examples, but it will be understood by those skilled in the art that the following embodiments and examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention. The specific conditions are not specified, and the process is carried out according to conventional conditions or conditions suggested by manufacturers. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.
In a first aspect, the invention provides a super-amphiphilic coating 10 capable of conducting lithium ions, which comprises an amphiphilic material 2 and a lithium ion conductor nano material 1, wherein the amphiphilic material 2 is coated on the surface of the lithium ion conductor nano material 1, and the schematic structure of the coating is shown in figure 1;
the amphiphilic material 2 comprises at least one of propoxyl glycerol triglycidyl ether polymer, polyvinylpyrrolidone, polydopamine, polyethylene glycol-polytetramethyl ether glycol copolymer or polyethylene glycol-polydimethylsiloxane copolymer, or other materials with amphiphilic effect which are well known to those skilled in the art;
The lithium ion conductor nanomaterial 1 includes, but is not limited to, at least one of NASICON-type oxide solid electrolyte, LISICON-type oxide solid electrolyte, gas-type oxide solid electrolyte, perovskie-type oxide solid electrolyte, or Anti-perovskie-type oxide solid electrolyte;
the particle size of the lithium ion conductor nano material 1 is 10-200nm.
The super-amphiphilic coating capable of conducting lithium ions, provided by the invention, has the advantages that the lithium ion conductor nano material provides good lithium ion conduction performance, the amphiphilic material coating layer and the lithium ion conductor nano material form a micro-nano structure, and super-oleophilic and super-hydrophilic capabilities can be provided. The super-amphiphilic coating capable of conducting lithium ions can be used as a coating of a diaphragm and a current collector of a lithium ion battery, has extremely strong electrolyte-philic capability, can accelerate the back suction of electrolyte, improves the liquid absorption capability of a battery core, does not influence the exertion of electrochemical performance, has good liquid-retaining capability, and is beneficial to relieving the extrusion of the electrolyte in the expansion process.
In some alternative embodiments, the mass ratio of the amphiphilic material to the lithium ion conductor nanomaterial may be, for example, but not limited to, 0.01:1, 0.1:1, 1:1, or 10:1.
In some alternative embodiments, the thickness of the lithium ion-conductive super-amphiphilic coating is 100nm-10 μm, which may be, for example, but not limited to, 100nm, 1 μm, or 10 μm.
In some alternative embodiments, the aqueous solvent of the super-amphiphilic coating has a static contact angle <5 °, the oil solvent has a static contact angle <5 °, and the various electrolytes have a static contact angle <5 °.
In some alternative embodiments, the NASICON-type oxide solid state electrolyte includes, but is not limited to, li 1.4Al0.4Ti1.6(PO4)3 or Li 1.5Al0.5Ge1.5(PO4)3;
The LISICON type oxide electrolyte includes, but is not limited to, gamma-Li 3PO4;
The Garnet-type oxide solid state electrolyte includes, but is not limited to, li 7La3Zr2O12 or Li 5La3Ta2O12;
the Perovskite type oxide solid state electrolyte includes, but is not limited to, li 0.5La0.5TiO3;
the Anti-perovskie oxide solid state electrolyte includes, but is not limited to, li 3 OCl.
In a second aspect, the invention provides a preparation method of the super-amphiphilic coating capable of conducting lithium ions, which comprises the following steps:
Mixing the amphiphilic material or a precursor thereof, the lithium ion conductor nano material and a solvent to form a dispersion liquid, then coating the dispersion liquid, and drying to prepare the super-amphiphilic coating capable of conducting lithium ions;
the solvent comprises at least one of ethanol, deionized water, n-hexane, tetrahydrofuran THF, heptane, isopropanol, carbon trichloride or carbon tetrachloride.
The preparation method is simple and convenient, and the prepared super-amphiphilic coating capable of conducting lithium ions has good super-oleophylic and super-hydrophilic capabilities.
In some alternative embodiments, the mass fraction of the lithium ion conductor nanomaterial in the dispersion may be, for example, but not limited to, 0.1%, 1%, or 10%.
In some alternative embodiments, the method of mixing includes one or more of magnetic stirring, vortex shaking, ultrasonic shaking, or mechanical stirring;
the mixing temperature is room temperature, and the mixing time is 1-48 hours.
In some alternative embodiments, the coating means comprises any one of spray coating, spin coating, dip coating, knife coating, brush coating.
In some alternative embodiments, the drying process comprises volatilizing at room temperature for 4 hours to 24 hours, or heat treating in an oven at 40 to 120 ℃ for 4 hours to 24 hours.
In a third aspect, the invention provides the use of a lithium ion-conductive superamphiphilic coating as described above in a battery.
The super-amphiphilic coating capable of conducting lithium ions, provided by the invention, is applied to a battery, and can effectively improve the liquid retaining capacity of the battery.
In a fourth aspect, the present invention provides a separator comprising a base film coated on a surface thereof with the lithium ion-conductive super-amphiphilic coating.
In a fifth aspect, the present invention provides a pole piece comprising a current collector, the surface of which is coated with the lithium ion-conductive super-amphiphilic coating.
In a sixth aspect, the present invention provides a lithium ion battery, including the separator and/or the pole piece.
The super-amphiphilic coating capable of conducting lithium ions is used as a coating of a diaphragm and a current collector of a lithium ion battery, has extremely strong electrolyte-philic capability, can accelerate the back suction of electrolyte, improves the liquid absorption capability of a battery core, does not influence the exertion of electrochemical performance, has good liquid-retaining capability, and is beneficial to relieving the extrusion of the electrolyte in the expansion process.
The invention is further illustrated by the following specific examples and comparative examples, but it should be understood that these examples are for the purpose of illustration only and are not to be construed as limiting the invention in any way.
Example 1
In the embodiment, an oxide solid electrolyte Li 1.4Al0.4Ti1.6(PO4)3 with the particle size of 50-100nm is selected as lithium ion conductive particles, and an amphiphilic polymer mainly composed of propoxyl glycerol triglycidyl ether (GPTE) is constructed on the surface of the oxide solid electrolyte Li 1.4Al0.4Ti1.6(PO4)3 through coupling reaction and crosslinking reaction to serve as a coating layer, so that a super-amphiphilic coating capable of conducting lithium ions is prepared on the surface of an aluminum foil, and the specific steps are as follows:
1. Adding Li 1.4Al0.4Ti1.6(PO4)3 particles with the particle size of 50-100nm into a mixed liquid of absolute ethyl alcohol and 1-methylpyrrole (V: V=100:0.01), and rapidly stirring at room temperature to fully disperse;
2. Dripping precursors of amphiphilic materials, namely propoxyl glycerol triglycidyl ether (GPTE) and Octadecylamine (ODA) (the mass ratio of the precursors to the octadecylamine is 50:1), into the dispersion, preparing a dispersion liquid by the precursors and Li 1.4Al0.4Ti1.6(PO4)3 particles according to the mass ratio of 1:10, stirring at room temperature for 6 hours and 50 ℃ for 15 minutes to obtain a uniform dispersion liquid, wherein the mass ratio of the Li 1.4Al0.4Ti1.6(PO4)3 particles in the dispersion liquid is about 0.1%;
3. Uniformly spraying the dispersion liquid on an aluminum foil;
4. drying the aluminum foil at room temperature for 5 minutes, and heating at 150 ℃ for 1 hour to complete crosslinking and curing to obtain the aluminum foil which is constructed by Li 1.4Al0.4Ti1.6(PO4)3 nano particles and is provided with the super-amphipathic coating capable of conducting lithium ions, wherein the thickness of the coating is 2 mu m;
5. preparing a lithium ion battery comprising the positive plate:
(1) Preparing an anode plate with the surface of the aluminum foil coated with the super-amphipathic coating capable of conducting lithium ions:
Uniformly mixing a positive electrode active material LiFePO 4, conductive carbon black (Super P) and a binder polyvinylidene fluoride (PVDF) in a mass ratio of 97.3:1.2:1.5 in a proper amount of N-methyl pyrrolidone (NMP) to prepare positive electrode slurry, coating the positive electrode slurry on the aluminum foil with the Super-amphipathic coating capable of conducting lithium ions, and preparing a positive electrode plate through procedures of rolling, slitting, punching and the like;
(2) Preparing a negative plate:
Uniformly mixing negative active material artificial graphite, conductive agent carbon black (Super P), binder styrene-butadiene rubber (SBR) and sodium carboxymethylcellulose (CMC-Na) in a proper amount of solvent deionized water according to a mass ratio of 95.5:1.7:1.6:1.2 to obtain negative electrode slurry, coating the negative electrode slurry on a negative electrode current collector copper foil, and obtaining a negative electrode plate through procedures of rolling, slitting, punching and the like;
(3) Preparing a diaphragm:
Use of commercial polypropylene separators;
(4) Preparing an electrolyte:
a mixed solvent of Ethylene Carbonate (EC) and ethylmethyl carbonate (EMC) was prepared at a mass ratio of 50:50, and then a sufficiently dried electrolyte salt LiPF 6 was dissolved therein (1.0 mol/L) to obtain an electrolyte.
(5) Preparation of lithium ion batteries
Sequentially laminating a positive electrode plate, a diaphragm and a negative electrode plate to obtain a pole core, placing the pole core in an outer package, baking, injecting electrolyte into the dried lithium ion battery, and performing the procedures of standing, formation, vacuum packaging, aging, capacity division and the like to obtain the secondary battery.
Example 2
In the embodiment, the oxide solid electrolyte Li 1.5Al0.5Ge1.5(PO4)3 with the particle size of 50-100nm is selected as lithium ion conductive particles, and a polyvinylpyrrolidone (PVP) amphiphilic polymer coating layer is constructed on the surface of the lithium ion conductive particles by a liquid phase coating method, so that a super-amphiphilic coating capable of conducting lithium ions is prepared on the surface of a polypropylene diaphragm, and the specific steps are as follows:
1. adding Li 1.5Al0.5Ge1.5(PO4)3 particles with the particle size of 50-100nm into PVP aqueous solution, wherein the mass ratio of PVP to Li 1.5Al0.5Ge1.5(PO4)3 is 1:5, performing ultrasonic-assisted dispersion at room temperature, and reacting for 6 hours under mechanical stirring to obtain uniform dispersion, wherein the mass ratio of Li 1.5Al0.5Ge1.5(PO4)3 in the dispersion is 1%;
2. preparing coatings on two sides of a polypropylene diaphragm by using an impregnation method, immersing the diaphragm in the dispersion liquid for 5s, and taking out;
3. Placing the diaphragm at room temperature for 12 hours to volatilize water, and placing the diaphragm in a vacuum oven at 60 ℃ for 24 hours to further remove the solvent, thus obtaining the diaphragm which is constructed by Li 1.5Al0.5Ge1.5(PO4)3 nano particles and has a super-amphipathic coating capable of conducting lithium ions and has the thickness of 5 mu m;
4. Preparing a lithium ion battery comprising the separator:
(1) Preparing a positive plate:
Uniformly mixing a positive active material LiFePO 4, conductive carbon black (Super P) and a binder polyvinylidene fluoride (PVDF) in a mass ratio of 97.3:1.2:1.5 in a proper amount of N-methyl pyrrolidone (NMP) to prepare positive electrode slurry, coating the positive electrode slurry on a current collector aluminum foil, and preparing a positive electrode plate through procedures of rolling, slitting, punching and the like;
(2) Preparing a negative plate:
Uniformly mixing negative active material artificial graphite, conductive agent carbon black (Super P), binder styrene-butadiene rubber (SBR) and sodium carboxymethylcellulose (CMC-Na) in a proper amount of solvent deionized water according to a mass ratio of 95.5:1.7:1.6:1.2 to obtain negative electrode slurry, coating the negative electrode slurry on a negative electrode current collector copper foil, and obtaining a negative electrode plate through procedures of rolling, slitting, punching and the like;
(3) A diaphragm:
The isolating membrane adopts the isolating membrane with the super-amphipathic coating capable of conducting lithium ions, which is constructed by the embodiment of the application;
(4) Preparing an electrolyte:
a mixed solvent of Ethylene Carbonate (EC) and ethylmethyl carbonate (EMC) was prepared at a mass ratio of 50:50, and then a sufficiently dried electrolyte salt LiPF 6 was dissolved therein (1.0 mol/L) to obtain an electrolyte.
(5) Preparation of lithium ion batteries
Sequentially laminating a positive electrode plate, a diaphragm and a negative electrode plate to obtain a pole core, placing the pole core in an outer package, baking, injecting electrolyte into the dried lithium ion battery, and performing the procedures of standing, formation, vacuum packaging, aging, capacity division and the like to obtain the secondary battery.
Example 3
In the embodiment, oxide solid electrolyte Li 7La3Zr2O12 with the particle size of 50-100nm is selected as lithium ion conductive particles, polyethylene glycol (PEG) -Polydimethylsiloxane (PDMS) is constructed on the surface of the particles through in-situ polymerization to be copolymerized as a coating layer, and then a super-amphipathic coating capable of conducting lithium ions is prepared on the surface of a copper foil, and the specific steps are as follows:
1. PEG (mn=2000) and PDMS (mn=1810) were added in a molar ratio of 1:1 and dissolved in tetrahydrofuran solvent (10 wt/vol%);
2. Li 7La3Zr2O12 particles with the particle size of 50-100nm, hexamethylene diisocyanate and dibutyltin dilaurate are added into the solution, and the mass ratio of the polymer precursors PEG and PDMS to Li 7La3Zr2O12 is 1:1. Stirring at room temperature for 24 hours, and carrying out coupling reaction to finally obtain uniform dispersion;
3. separating out a precipitate from the prepared dispersion, washing the precipitate with deionized water for 3 times, and then drying the precipitate in vacuum at 80 ℃ for 24 hours to obtain Li 7La3Zr2O12 nano-particles coated with the PEG-PDMS copolymer;
4. dispersing Li 7La3Zr2O12 nano particles coated with PEG-PDMS copolymer in deionized water, magnetically stirring at room temperature and performing subsequent ultrasonic dispersion to prepare a dispersion liquid, wherein the mass ratio of Li 7La3Zr2O12 in the dispersion liquid is about 5%;
5. uniformly coating the dispersion on the copper foil by using a knife coating method;
6. Placing the diaphragm at room temperature for 12 hours to volatilize water, and placing the diaphragm in a vacuum oven at 60 ℃ for 24 hours to further remove the solvent, thus obtaining the copper foil with the super-amphipathic coating capable of conducting lithium ions, which is constructed by Li 7La3Zr2O12 nano particles coated with PEG-PDMS copolymer, wherein the thickness of the coating is 100 nm;
7. Preparing a lithium ion battery comprising the negative plate:
(1) Preparing a positive plate:
Uniformly mixing a positive electrode active material LiFePO 4, conductive carbon black (Super P) and a binder polyvinylidene fluoride (PVDF) in a mass ratio of 97.3:1.2:1.5 in a proper amount of N-methyl pyrrolidone (NMP) to prepare positive electrode slurry, coating the positive electrode slurry on the aluminum foil with the Super-amphipathic coating capable of conducting lithium ions, and preparing a positive electrode plate through procedures of rolling, slitting, punching and the like;
(2) Preparing a negative plate with the surface of the copper foil coated with the super-amphipathic coating capable of conducting lithium ions:
Uniformly mixing negative active material artificial graphite, conductive agent carbon black (Super P), binder styrene-butadiene rubber (SBR) and sodium carboxymethylcellulose (CMC-Na) in a proper amount of solvent deionized water according to a mass ratio of 95.5:1.7:1.6:1.2 to obtain negative electrode slurry, coating the negative electrode slurry on the copper foil with the Super-amphipathic coating capable of conducting lithium ions, and obtaining a negative electrode plate through procedures of rolling, slitting, punching and the like;
(3) Preparing a diaphragm:
Use of commercial polypropylene separators;
(4) Preparing an electrolyte:
a mixed solvent of Ethylene Carbonate (EC) and ethylmethyl carbonate (EMC) was prepared at a mass ratio of 50:50, and then a sufficiently dried electrolyte salt LiPF 6 was dissolved therein (1.0 mol/L) to obtain an electrolyte.
(5) Preparation of lithium ion batteries
Sequentially laminating a positive electrode plate, a diaphragm and a negative electrode plate to obtain a pole core, placing the pole core in an outer package, baking, injecting electrolyte into the dried lithium ion battery, and performing the procedures of standing, formation, vacuum packaging, aging, capacity division and the like to obtain the secondary battery.
Example 4
In the embodiment, oxide solid electrolyte Li 0.5La0.5TiO3 with particle size of 10-50 nm is selected as lithium ion conductive particles, and a polydopamine coating layer is constructed on the surface of the lithium ion conductive particles through in-situ polymerization, so that a super-amphipathic coating layer capable of conducting lithium ions is prepared on the surface of a diaphragm, and the specific steps are as follows:
1. Li 0.5La0.5TiO3 nanoparticles were dispersed in tris (hydroxymethyl) aminomethane hydrochloride buffer (50.0 mmol/L, pH 8.5) at a rate of about 1g/1000ml;
2. Adding a certain amount of dopamine into the dispersion liquid, wherein the mass ratio of the dopamine to Li 0.5La0.5TiO3 is about 10:1, and after stirring for 12 hours at normal temperature, synthesizing a uniform dispersion liquid of polydopamine coated Li 0.5La0.5TiO3, wherein the mass ratio of Li 0.5La0.5TiO3 in the dispersion liquid is about 0.1%;
3. preparing coatings on two sides of a polypropylene diaphragm by using an impregnation method, immersing the diaphragm in the dispersion liquid for 5s, and taking out;
4. Placing the diaphragm at room temperature for 12 hours to volatilize water, and placing the diaphragm in a vacuum oven at 60 ℃ for 24 hours to further remove the solvent, thus obtaining the diaphragm which is constructed by the Li 0.5La0.5TiO3 nano particles coated by the polydopamine and has the super-amphipathic coating capable of conducting lithium ions, wherein the thickness of the coating is 1 mu m;
5. Preparing a lithium ion battery comprising the separator:
(1) Preparing a positive plate:
Uniformly mixing a positive active material LiFePO 4, conductive carbon black (Super P) and a binder polyvinylidene fluoride (PVDF) in a mass ratio of 97.3:1.2:1.5 in a proper amount of N-methyl pyrrolidone (NMP) to prepare positive electrode slurry, coating the positive electrode slurry on a current collector aluminum foil, and preparing a positive electrode plate through procedures of rolling, slitting, punching and the like;
(2) Preparing a negative plate:
Uniformly mixing negative active material artificial graphite, conductive agent carbon black (Super P), binder styrene-butadiene rubber (SBR) and sodium carboxymethylcellulose (CMC-Na) in a proper amount of solvent deionized water according to a mass ratio of 95.5:1.7:1.6:1.2 to obtain negative electrode slurry, coating the negative electrode slurry on a negative electrode current collector copper foil, and obtaining a negative electrode plate through procedures of rolling, slitting, punching and the like;
(3) A diaphragm:
The isolating membrane adopts the isolating membrane with the super-amphipathic coating capable of conducting lithium ions, which is constructed by the embodiment of the application;
(4) Preparing an electrolyte:
a mixed solvent of Ethylene Carbonate (EC) and ethylmethyl carbonate (EMC) was prepared at a mass ratio of 50:50, and then a sufficiently dried electrolyte salt LiPF 6 was dissolved therein (1.0 mol/L) to obtain an electrolyte.
(5) Preparation of lithium ion batteries
Sequentially laminating a positive electrode plate, a diaphragm and a negative electrode plate to obtain a pole core, placing the pole core in an outer package, baking, injecting electrolyte into the dried lithium ion battery, and performing the procedures of standing, formation, vacuum packaging, aging, capacity division and the like to obtain the secondary battery.
Example 5
In the embodiment, solid electrolyte Li 3 OCl with the particle size of 100-200nm is selected as lithium ion conductive particles, polyethylene glycol (PEG) -polytetramethylene ether glycol (PTMEG) is constructed on the surface of the solid electrolyte Li 3 OCl through in-situ polymerization to be copolymerized as a coating layer, and then the super-amphipathic coating capable of conducting lithium ions is prepared on the surface of a copper foil, and the specific steps are as follows:
1. PEG (mn=2000) and PTMEG (mn=2000) were added in a molar ratio of 1:1 and dissolved in tetrahydrofuran solvent (10 wt/vol%);
2. Li 3 OCl particles with the particle size of 100-200nm, hexamethylene diisocyanate and dibutyltin dilaurate were added to the above solution, and the mass ratio of the total mass of the polymer precursors PEG and PTMEG to Li 3 OCl was 0.01:1. Stirring at room temperature for 24 hours, and carrying out coupling reaction to finally obtain uniform dispersion;
3. Separating out the precipitate from the prepared dispersion, washing the precipitate with deionized water for 3 times, and then drying the precipitate in vacuum at 80 ℃ for 24 hours to obtain Li 3 OCl nano-particles coated with the PEG-PTMEG copolymer;
4. Dispersing Li 3 OCl nano-particles coated with PEG-PTMEG copolymer in deionized water, and preparing a dispersion liquid by magnetic stirring at room temperature and subsequent ultrasonic dispersion, wherein the mass ratio of Li 3 OCl in the dispersion liquid is about 10%;
5. uniformly coating the dispersion liquid on an aluminum foil by using a knife coating method;
6. Placing the diaphragm at room temperature for 12 hours to volatilize water, and placing the diaphragm in a vacuum oven at 60 ℃ for 24 hours to further remove the solvent, thus obtaining the aluminum foil which is constructed by Li 3 OCl nano particles and has a super-amphipathic coating capable of conducting lithium ions and is coated with PEG-PTMEG copolymer, wherein the thickness of the coating is 10 mu m;
7. preparing a lithium ion battery comprising the positive plate:
(1) Preparing an anode plate with the surface of the aluminum foil coated with the super-amphipathic coating capable of conducting lithium ions:
Uniformly mixing a positive electrode active material LiFePO 4, conductive carbon black (Super P) and a binder polyvinylidene fluoride (PVDF) in a mass ratio of 97.3:1.2:1.5 in a proper amount of N-methyl pyrrolidone (NMP) to prepare positive electrode slurry, coating the positive electrode slurry on the aluminum foil with the Super-amphipathic coating capable of conducting lithium ions, and preparing a positive electrode plate through procedures of rolling, slitting, punching and the like;
(2) Preparing a negative plate:
Uniformly mixing negative active material artificial graphite, conductive agent carbon black (Super P), binder styrene-butadiene rubber (SBR) and sodium carboxymethylcellulose (CMC-Na) in a proper amount of solvent deionized water according to a mass ratio of 95.5:1.7:1.6:1.2 to obtain negative electrode slurry, coating the negative electrode slurry on a negative electrode current collector copper foil, and obtaining a negative electrode plate through procedures of rolling, slitting, punching and the like;
(3) Preparing a diaphragm:
Use of commercial polypropylene separators;
(4) Preparing an electrolyte:
a mixed solvent of Ethylene Carbonate (EC) and ethylmethyl carbonate (EMC) was prepared at a mass ratio of 50:50, and then a sufficiently dried electrolyte salt LiPF 6 was dissolved therein (1.0 mol/L) to obtain an electrolyte.
(5) Preparation of lithium ion batteries
Sequentially laminating a positive electrode plate, a diaphragm and a negative electrode plate to obtain a pole core, placing the pole core in an outer package, baking, injecting electrolyte into the dried lithium ion battery, and performing the procedures of standing, formation, vacuum packaging, aging, capacity division and the like to obtain the secondary battery.
Comparative example 1
A coating differing from example 1 in that the particle size of the lithium ion conducting particles is 1-5. Mu.m.
In the embodiment, an oxide solid electrolyte Li 1.4Al0.4Ti1.6(PO4)3 with a particle size of 1-5 μm is selected as lithium ion conductive particles, and an amphiphilic polymer mainly composed of propoxyl glycerol triglycidyl ether (GPTE) is structured on the surface of the oxide solid electrolyte Li 1.4Al0.4Ti1.6(PO4)3 through coupling reaction and crosslinking reaction to serve as a coating layer, so that a super-amphiphilic coating capable of conducting lithium ions is prepared on the surface of an aluminum foil, and the specific steps are as follows:
1. Adding Li 1.4Al0.4Ti1.6(PO4)3 particles with the particle size of 1-5 μm into a mixed liquid of absolute ethyl alcohol and 1-methylpyrrole (V: V=100:0.01), and rapidly stirring at room temperature to fully disperse, wherein the solid content of the dispersion is 0.1%;
2. Dripping precursors of amphiphilic materials, namely propoxyl glycerol triglycidyl ether (GPTE) and Octadecylamine (ODA) (the mass ratio of the precursors to the octadecylamine is 50:1), into the dispersion, preparing a dispersion liquid by the precursors and Li 1.4Al0.4Ti1.6(PO4)3 particles according to the mass ratio of 1:10, stirring at room temperature for 6 hours and 50 ℃ for 15 minutes to obtain a uniform dispersion liquid, wherein the mass ratio of the Li 1.4Al0.4Ti1.6(PO4)3 particles in the dispersion liquid is about 0.1%;
3. Uniformly spraying the dispersion liquid on an aluminum foil;
4. Drying the aluminum foil at room temperature for 5 minutes, and heating at 150 ℃ for 1 hour to complete crosslinking and curing to obtain the aluminum foil which is constructed by Li 1.4Al0.4Ti1.6(PO4)3 particles and is coated with the amphiphilic polymer and provided with the super-amphiphilic coating capable of conducting lithium ions, wherein the thickness of the coating is 2 mu m;
5. preparing a lithium ion battery comprising the positive plate:
(1) Preparing an anode plate with the surface of the aluminum foil coated with the super-amphipathic coating capable of conducting lithium ions:
Uniformly mixing a positive electrode active material LiFePO 4, conductive carbon black (Super P) and a binder polyvinylidene fluoride (PVDF) in a mass ratio of 97.3:1.2:1.5 in a proper amount of N-methyl pyrrolidone (NMP) to prepare positive electrode slurry, coating the positive electrode slurry on the aluminum foil with the Super-amphipathic coating capable of conducting lithium ions, and preparing a positive electrode plate through procedures of rolling, slitting, punching and the like;
(2) Preparing a negative plate:
Uniformly mixing negative active material artificial graphite, conductive agent carbon black (Super P), binder styrene-butadiene rubber (SBR) and sodium carboxymethylcellulose (CMC-Na) in a proper amount of solvent deionized water according to a mass ratio of 95.5:1.7:1.6:1.2 to obtain negative electrode slurry, coating the negative electrode slurry on a negative electrode current collector copper foil, and obtaining a negative electrode plate through procedures of rolling, slitting, punching and the like;
(3) Preparing a diaphragm:
Use of commercial polypropylene separators;
(4) Preparing an electrolyte:
a mixed solvent of Ethylene Carbonate (EC) and ethylmethyl carbonate (EMC) was prepared at a mass ratio of 50:50, and then a sufficiently dried electrolyte salt LiPF 6 was dissolved therein (1.0 mol/L) to obtain an electrolyte.
(5) Preparation of lithium ion batteries
Sequentially laminating a positive electrode plate, a diaphragm and a negative electrode plate to obtain a pole core, placing the pole core in an outer package, baking, injecting electrolyte into the dried lithium ion battery, and performing the procedures of standing, formation, vacuum packaging, aging, capacity division and the like to obtain the secondary battery.
Comparative example 2
A coating differing from example 1 in that no lithium ion conductor material was included.
In the embodiment, the amphiphilic polymer coating mainly comprising propoxyl glycerol triglycidyl ether (GPTE) is constructed on the surface of the aluminum foil through coupling reaction and crosslinking reaction, and the specific steps are as follows:
1. Dripping precursor of amphiphilic material, namely propoxyglycerol triglycidyl ether (GPTE) and Octadecylamine (ODA) (the mass ratio of the propoxyglycerol triglycidyl ether to the octadecylamine is 50:1) into mixed liquid of absolute ethyl alcohol and 1-methylpyrrole (V: V=100:0.01), stirring for 6 hours at room temperature and stirring for 15 minutes at 50 ℃ to obtain a uniform solution;
2. uniformly spraying the solution on an aluminum foil;
3. Drying the aluminum foil at room temperature for 5 minutes, and heating at 150 ℃ for 1 hour to complete crosslinking and curing to obtain the aluminum foil with the amphiphilic polymer coating, wherein the thickness of the coating is 2 mu m;
4. Preparing a lithium ion battery comprising the positive plate:
(1) Preparing a positive electrode plate with the surface of the aluminum foil coated with the amphiphilic polymer coating:
Uniformly mixing anode active materials LiFePO 4, conductive carbon black (Super P) and a binder polyvinylidene fluoride (PVDF) in a mass ratio of 97.3:1.2:1.5 in a proper amount of N-methyl pyrrolidone (NMP) to prepare anode slurry, coating the anode slurry on the aluminum foil with the amphiphilic polymer coating, and preparing an anode sheet through procedures of rolling, slitting, punching and the like;
(2) Preparing a negative plate:
Uniformly mixing negative active material artificial graphite, conductive agent carbon black (Super P), binder styrene-butadiene rubber (SBR) and sodium carboxymethylcellulose (CMC-Na) in a proper amount of solvent deionized water according to a mass ratio of 95.5:1.7:1.6:1.2 to obtain negative electrode slurry, coating the negative electrode slurry on a negative electrode current collector copper foil, and obtaining a negative electrode plate through procedures of rolling, slitting, punching and the like;
(3) Preparing a diaphragm:
Use of commercial polypropylene separators;
(4) Preparing an electrolyte:
a mixed solvent of Ethylene Carbonate (EC) and ethylmethyl carbonate (EMC) was prepared at a mass ratio of 50:50, and then a sufficiently dried electrolyte salt LiPF 6 was dissolved therein (1.0 mol/L) to obtain an electrolyte.
(5) Preparation of lithium ion batteries
Sequentially laminating a positive electrode plate, a diaphragm and a negative electrode plate to obtain a pole core, placing the pole core in an outer package, baking, injecting electrolyte into the dried lithium ion battery, and performing the procedures of standing, formation, vacuum packaging, aging, capacity division and the like to obtain the secondary battery.
Comparative example 3
A coating differing from example 1 in that it does not include an amphiphilic material.
In the embodiment, the oxide solid electrolyte Li 1.4Al0.4Ti1.6(PO4)3 with the particle size of 50-100nm is selected as lithium ion conducting particles, and a coating only containing solid electrolyte nano particles is prepared on the surface of an aluminum foil, which comprises the following specific steps:
1. Adding Li 1.4Al0.4Ti1.6(PO4)3 particles with the particle size of 50-100nm into an absolute ethyl alcohol solvent, rapidly stirring at room temperature for full dispersion, and preparing a dispersion liquid with the solid content of 0.1% by using polyethylene glycol as a dispersing agent, ultrasonic treatment and other methods;
2. uniformly spraying the dispersion liquid on an aluminum foil;
3. Drying the aluminum foil at room temperature for 5 minutes, and heating at 150 ℃ for 1 hour to further volatilize the solvent, so as to obtain the aluminum foil with the Li 1.4Al0.4Ti1.6(PO4)3 nano-particle coating, wherein the thickness of the coating is 2 mu m;
4. Preparing a lithium ion battery comprising the positive plate:
(1) Preparing an anode plate with the surface of the aluminum foil coated with the lithium ion conductor coating:
Uniformly mixing a positive active material LiFePO 4, conductive carbon black (Super P) and a binder polyvinylidene fluoride (PVDF) in a mass ratio of 97.3:1.2:1.5 in a proper amount of N-methyl pyrrolidone (NMP) to prepare positive electrode slurry, coating the positive electrode slurry on the aluminum foil of the lithium ion conductor coating, and preparing a positive electrode plate through procedures of rolling, slitting, punching and the like;
(2) Preparing a negative plate:
Uniformly mixing negative active material artificial graphite, conductive agent carbon black (Super P), binder styrene-butadiene rubber (SBR) and sodium carboxymethylcellulose (CMC-Na) in a proper amount of solvent deionized water according to a mass ratio of 95.5:1.7:1.6:1.2 to obtain negative electrode slurry, coating the negative electrode slurry on a negative electrode current collector copper foil, and obtaining a negative electrode plate through procedures of rolling, slitting, punching and the like;
(3) Preparing a diaphragm:
Use of commercial polypropylene separators;
(4) Preparing an electrolyte:
a mixed solvent of Ethylene Carbonate (EC) and ethylmethyl carbonate (EMC) was prepared at a mass ratio of 50:50, and then a sufficiently dried electrolyte salt LiPF 6 was dissolved therein (1.0 mol/L) to obtain an electrolyte.
(5) Preparation of lithium ion batteries
Sequentially laminating a positive electrode plate, a diaphragm and a negative electrode plate to obtain a pole core, placing the pole core in an outer package, baking, injecting electrolyte into the dried lithium ion battery, and performing the procedures of standing, formation, vacuum packaging, aging, capacity division and the like to obtain the secondary battery.
Comparative example 4
The difference from example 1 is that an unmodified aluminum foil was used.
Preparing a lithium ion battery:
(1) Preparing a positive plate:
Uniformly mixing a positive active material LiFePO 4, conductive carbon black (Super P) and a binder polyvinylidene fluoride (PVDF) in a mass ratio of 97.3:1.2:1.5 in a proper amount of N-methyl pyrrolidone (NMP) to prepare positive electrode slurry, coating the positive electrode slurry on an unmodified aluminum foil, and preparing a positive electrode plate through procedures of rolling, slitting, punching and the like;
(2) Preparing a negative plate:
Uniformly mixing negative active material artificial graphite, conductive agent carbon black (Super P), binder styrene-butadiene rubber (SBR) and sodium carboxymethylcellulose (CMC-Na) in a proper amount of solvent deionized water according to a mass ratio of 95.5:1.7:1.6:1.2 to obtain negative electrode slurry, coating the negative electrode slurry on a negative electrode current collector copper foil, and obtaining a negative electrode plate through procedures of rolling, slitting, punching and the like;
(3) Preparing a diaphragm:
Use of commercial polypropylene separators;
(4) Preparing an electrolyte:
a mixed solvent of Ethylene Carbonate (EC) and ethylmethyl carbonate (EMC) was prepared at a mass ratio of 50:50, and then a sufficiently dried electrolyte salt LiPF 6 was dissolved therein (1.0 mol/L) to obtain an electrolyte.
(5) Preparation of lithium ion batteries
Sequentially laminating a positive electrode plate, a diaphragm and a negative electrode plate to obtain a pole core, placing the pole core in an outer package, baking, injecting electrolyte into the dried lithium ion battery, and performing the procedures of standing, formation, vacuum packaging, aging, capacity division and the like to obtain the secondary battery.
The separators, pole pieces and lithium ion batteries prepared in examples 1 to 5 and comparative examples 1 to 4 were evaluated by the wettability test, the cycle 1500 lithium precipitation test and the capacity retention test.
Performance test method
1. Wettability test of separator and pole piece for aqueous solvent, oily solvent and electrolyte:
According to the invention, the wetting performance of the electrolyte is judged through different types of solvents and the contact angle of the electrolyte on the surfaces of the diaphragm and the pole piece materials. The static contact angle of the solvent and the electrolyte after being added to the sample surface for 6s was measured by using a contact angle tester, and the result of 5 repeated tests was taken as a final result.
EC was selected as a representative of the aqueous solvent, EMC was selected as a representative of the oily solvent, and the electrolyte was represented by a formulation in which Ethylene Carbonate (EC) and ethylmethyl carbonate (EMC) were prepared as mixed solvents in a mass ratio of 50:50, and then a sufficiently dried electrolyte salt LiPF 6 was dissolved therein (1.0 mol/L) to obtain an electrolyte.
2. And (3) cell cycle lithium precipitation test:
And disassembling the battery after 1500 weeks of circulation, and observing the lithium separation condition of the interface. The lithium precipitation degree in the center of the pole piece is judged, so that the improvement effect of the super-amphiphilic coating capable of conducting lithium ions on lithium precipitation caused by the lack of liquid in the middle of the battery cell in the circulation process is evaluated.
The circulation condition is 25 ℃,1C/1C, and the circulation is 1500 times.
The lithium precipitation degree judgment standard is that the lithium precipitation area in the center of the pole piece accounts for the percentage of the total area of the pole piece:
3. Capacity retention rate of 1500 cycles:
The cycle capacity retention rate of 1500 weeks of the battery cell is taken as a basis to evaluate the effect of the super-amphiphilic coating capable of conducting lithium ions on improving the cycle life.
The circulation condition is 25 ℃,1C/1C, and the circulation is 1500 times.
The capacity retention rate was calculated by 1500 weeks discharge capacity/initial discharge capacity.
Test results:
the test results of examples 1-5 show the technical effect on positive and negative plates and cells when the lithium ion-conductive ultra-amphiphilic coating is applied to aluminum foils, copper foils and diaphragms.
(1) The positive and negative plates and the diaphragm applying the coating have super-affinity properties for water-based and oil-based solvents in the electrolyte, and the contact angles of the positive and negative plates and the diaphragm for the water-based EC and the oil-based EMC solvents are all smaller than 5 degrees, so that the super-affinity properties (contact angle for the electrolyte is smaller than 5 degrees) of the electrolyte are realized.
(2) Furthermore, the positive and negative plates and the diaphragm with the coating have good wettability in the circulation process, can accelerate the back suction of electrolyte, improve the liquid suction capacity of the battery cell, and are beneficial to relieving the extrusion of the electrolyte in the expansion process. After 1500 cycles of the battery cell with the positive and negative plates and the diaphragm with the coating are applied, the lithium precipitation degree is low.
(3) In contrast, the capacity retention rate at 1500 weeks was excellent.
Comparative examples 1, 2, 3 and 4 are compared with example 1 to demonstrate the necessity of combining both materials of the amphiphilic material and the lithium ion conductor nanomaterial when constructing the lithium ion conductive super-amphiphilic coating.
(1) Comparative example 4 is an anode sheet and a battery cell prepared from unmodified aluminum foil, the contact angle of the anode sheet to EC, EMC and electrolyte is larger, the lithium precipitation degree corresponding to 1500 weeks of cycle is larger, and the cycle capacity retention rate is lower;
(2) The coating structure of comparative example 1 uses Li 1.4Al0.4Ti1.6(PO4)3 particles of 1-5 μm particle diameter coated with propoxylated glycerol triglycidyl ether polymer, and the coating formed lacks micro-nano structure required for super-amphiphilicity function, thus improving affinity to oily, aqueous solvents, and electrolytes only to some extent;
(3) Comparative example 2 uses only propoxylated triglycidyl ether polymer as a coating, and the interface is constructed to have only amphiphilic function, which is far lower than the wettability of the positive electrode sheet with the coating in example 1 to EC, EMC and electrolyte;
(4) Comparative example 3 uses nano Li 1.4Al0.4Ti1.6(PO4)3 electrolyte particles with a particle size of 50-100nm to construct a coating, which has a certain affinity for both EC solvents and electrolytes due to its polarity, but its affinity is still lower, the degree of lithium precipitation in the cycle is higher, and the capacity retention is correspondingly poor, compared to the super-amphiphilic coating constructed in example 1.
It should be noted that the above embodiments are merely for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that the technical solution described in the above embodiments may be modified or some or all of the technical features may be equivalently replaced, and these modifications or substitutions do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the present invention.
Claims (6)
1. The pole piece is characterized by comprising a current collector, wherein the surface of the current collector is coated with a super-amphipathic coating capable of conducting lithium ions;
The super-amphiphilic coating capable of conducting lithium ions comprises an amphiphilic material and a lithium ion conductor nano material, wherein the amphiphilic material is coated on the surface of the lithium ion conductor nano material;
The amphiphilic material comprises at least one of propoxyl glycerol triglycidyl ether polymer, polyvinylpyrrolidone, polydopamine, polyethylene glycol-polytetramethyl ether glycol copolymer or polyethylene glycol-polydimethylsiloxane copolymer;
The lithium ion conductor nanomaterial comprises at least one of NASICON type oxide solid electrolyte, LISICON type oxide electrolyte, garnet type oxide solid electrolyte, perovskite type oxide solid electrolyte or Anti-Perovskite type oxide solid electrolyte;
the particle size of the lithium ion conductor nano material is 10-200nm;
the static contact angle of the super-amphiphilic coating to ethylene carbonate is less than 5 degrees, and the static contact angle of the super-amphiphilic coating to methyl ethyl carbonate is less than 5 degrees.
2. The pole piece of claim 1, wherein the mass ratio of the amphiphilic material to the lithium ion conductor nanomaterial is 0.01:1-10:1.
3. The pole piece of claim 1, wherein the NASICON-type oxide solid state electrolyte comprises Li 1.4Al0.4Ti1.6(PO4)3 or Li 1.5Al0.5Ge1.5(PO4)3;
the LISICON type oxide electrolyte comprises gamma-Li 3PO4;
the Garnet-type oxide solid electrolyte comprises Li 7La3Zr2O12 or Li 5La3Ta2O12;
The Perovskite type oxide solid state electrolyte comprises Li 0.5La0.5TiO3;
The Anti-perovskie oxide solid state electrolyte comprises Li 3 OCl.
4. A pole piece according to any of claims 1-3, characterized in that the preparation method of the lithium ion conductive super-amphiphilic coating comprises the steps of:
Mixing the amphiphilic material or a precursor thereof, the lithium ion conductor nano material and a solvent to form a dispersion liquid, then coating the dispersion liquid, and drying to prepare the super-amphiphilic coating capable of conducting lithium ions;
the solvent comprises at least one of ethanol, deionized water, n-hexane, tetrahydrofuran THF, heptane, isopropanol, carbon trichloride or carbon tetrachloride.
5. The pole piece of claim 4, wherein the mass ratio of the lithium ion conductor nanomaterial in the dispersion is 0.1% -10%.
6. A lithium ion battery comprising the pole piece of claim 1.
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| CN105789538A (en) * | 2016-04-20 | 2016-07-20 | 宁德时代新能源科技股份有限公司 | Separator, preparation method thereof and secondary battery containing separator |
| CN110391386A (en) * | 2019-08-01 | 2019-10-29 | 青岛上惠新材料科技有限公司 | A kind of composite diaphragm and its preparation method and application |
| CN112701345A (en) * | 2020-12-29 | 2021-04-23 | 长三角物理研究中心有限公司 | Super-hydrophobic material capable of conducting lithium ions as well as preparation method and application thereof |
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