WO2024087817A1 - Feuille d'électrode négative et batterie au lithium-ion - Google Patents

Feuille d'électrode négative et batterie au lithium-ion Download PDF

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Publication number
WO2024087817A1
WO2024087817A1 PCT/CN2023/113334 CN2023113334W WO2024087817A1 WO 2024087817 A1 WO2024087817 A1 WO 2024087817A1 CN 2023113334 W CN2023113334 W CN 2023113334W WO 2024087817 A1 WO2024087817 A1 WO 2024087817A1
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negative electrode
electrode sheet
lithium
ion battery
sheet according
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PCT/CN2023/113334
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English (en)
Chinese (zh)
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张健
彭冲
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珠海冠宇电池股份有限公司
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Publication of WO2024087817A1 publication Critical patent/WO2024087817A1/fr

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • 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
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • 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
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/4235—Safety or regulating additives or arrangements in electrodes, separators or electrolyte
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • 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
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present application belongs to the field of lithium-ion batteries and relates to a negative electrode sheet and a lithium-ion battery.
  • Lithium-ion batteries have a high probability of failure when subjected to mechanical abuse (such as needle puncture, extrusion, etc.) because when the battery is mechanically damaged, a relatively serious short circuit will occur inside, such as a short circuit between the positive current collector and the negative current collector, a short circuit between the positive current collector and the negative electrode coating, a short circuit between the positive electrode coating and the negative current collector, and a short circuit between the positive electrode coating and the negative electrode coating.
  • the short circuit caused by the contact between the positive current collector and the negative electrode coating generates the fastest heat and is most likely to cause thermal runaway.
  • a protective layer including an inorganic filler, a conductive agent, and an adhesive is usually provided on the surface of the negative electrode active layer to prevent the positive current collector of the battery from contacting and short-circuiting with the negative electrode active layer.
  • the content of the conductive agent in the protective layer is relatively small and the conductive agent is prone to agglomeration, making it difficult to disperse evenly in the protective layer, and it is impossible to ensure that the cycle performance of the battery is not affected while improving the safety performance of the battery. Therefore, how to make lithium-ion batteries take into account both good safety performance and cycle performance is a technical problem that needs to be solved urgently in this field.
  • the present application provides a negative electrode sheet, which can prevent the positive electrode collector and the negative electrode active layer from short-circuiting when the lithium-ion battery is mechanically abused by setting a negative electrode protective layer.
  • a negative electrode protective layer which can make the lithium-ion battery have excellent safety performance and cycle performance.
  • the present application also provides a lithium-ion battery, which has good safety performance and cycle performance because it includes the above-mentioned negative electrode sheet.
  • the present application provides a negative electrode sheet, comprising a negative electrode current collector, a negative electrode protection layer, and a negative electrode active layer disposed between the negative electrode current collector and the negative electrode protection layer;
  • the negative electrode active layer comprises conductive particles and a binder, wherein the conductive particles are inorganic fillers having a conductive coating layer on the surface.
  • the negative electrode current collector of the present application can be selected from negative electrode current collectors conventionally used in the art, such as copper foil or carbon-coated copper foil, which are generally commercially available.
  • the present application does not particularly limit the composition of the negative electrode active layer, which can be selected from the negative electrode active layer composition conventionally used in the art.
  • the negative electrode active layer can be composed of components such as a negative electrode active material, a binder, and a conductive agent.
  • the negative electrode active material, the binder, and the conductive agent can all be selected from conventional materials used in the art.
  • the negative electrode active material can be selected from one or more of artificial graphite, natural graphite, silicon oxides, silicon-carbon mixtures, hard carbon materials, and lithium titanate.
  • the conductive agent can be selected from one or more of conductive carbon black, carbon nanotubes, conductive graphite, and graphene.
  • the binder can be selected from one or more of polyvinylidene fluoride (PVDF), acrylic acid-modified PVDF, polyacrylate polymers, polyimide, styrene-butadiene rubber, styrene-acrylic rubber, and carboxymethyl cellulose salts.
  • PVDF polyvinylidene fluoride
  • acrylic acid-modified PVDF acrylic acid-modified PVDF
  • polyacrylate polymers polyimide
  • styrene-butadiene rubber styrene-acrylic rubber
  • carboxymethyl cellulose salts carboxymethyl cellulose salts
  • the negative electrode protection layer of the present application includes conductive particles and adhesives, wherein the conductive particles are inorganic fillers coated with a conductive coating layer on the surface, wherein the inorganic filler has the characteristics of high mechanical strength, good stability, and good heat resistance.
  • the inorganic filler can protect the negative electrode active layer well, making it difficult to be exposed, thereby reducing the probability of short circuit caused by contact between the positive electrode collector and the negative electrode active layer, and improving the safety performance of the battery.
  • the adhesive is also an indispensable component to ensure that the negative electrode protection layer can be firmly bonded to the negative electrode active layer.
  • the negative electrode protection layer of the present application is composed of a conductive material and a binder.
  • the conductive particles used in the present application provide the negative electrode protective layer with a good conductive network by coating the surface of the inorganic filler with a conductive layer, and the excellent dispersibility of the inorganic filler itself also brings good dispersibility to the conductive particles with conductive function, thereby The battery has excellent safety performance and good cycle performance.
  • a negative electrode protection layer can significantly improve the safety performance of the battery in the event of mechanical abuse, but it will also have an adverse effect on the energy density of the battery. Therefore, depending on the needs of the battery, it is possible to choose to provide a negative electrode protection layer only on one side of the negative electrode current collector or to provide a negative electrode protection layer on both sides of the negative electrode current collector.
  • the material of the conductive coating layer is selected from at least one of ATO, FTO, ITO and carbon materials, more preferably at least one of ATO, FTO and ITO, and even more preferably ATO.
  • ATO refers to antimony-doped tin dioxide
  • FTO fluorine-doped tin dioxide
  • ITO tin-doped indium oxide
  • Nano conductive material carbon black has dark color and poor dispersibility, which limits its application.
  • Cheap metal conductive materials such as copper, iron, and aluminum are prone to oxidation, and their conductivity will decrease over time.
  • Nano conductive materials such as ATO, FTO, and ITO have better dispersibility and stability, and have obvious advantages over traditional conductive materials.
  • the doping amount of antimony in ATO is ⁇ 30%
  • the doping amount of fluorine in FTO is ⁇ 10%
  • the doping amount of tin in ITO is ⁇ 30%.
  • the doping amount refers to the mass content of antimony in ATO.
  • the inorganic filler of the present application is selected from lithium transition metal oxides and/or ceramic materials, and specifically can be selected from at least one of aluminum oxide, magnesium oxide, titanium oxide, zinc oxide, silicon oxide, boehmite, cobalt oxide, iron phosphate, lithium iron phosphate, lithium nickel cobalt manganese oxide, and lithium iron manganese phosphate.
  • the present application does not specifically limit the type of adhesive, as long as it can ensure effective bonding between the negative electrode protection layer and the negative electrode active layer.
  • the adhesive of the present application can be specifically selected from at least one of polyvinylidene fluoride (PVDF), acrylic acid-modified PVDF, polyacrylate polymers, polyimide, styrene-butadiene rubber, and styrene-acrylic rubber.
  • the mass content of the conductive coating layer in the conductive particles can be controlled so that the lithium-ion battery has good conductivity on the basis of excellent safety performance.
  • the present application also limits the content of conductive particles and the content of adhesive in the negative electrode protective layer.
  • the negative electrode protective layer includes 70% to 95% of conductive particles and 5% to 30% of adhesive by mass.
  • the resistance of the negative electrode protective layer has a dual impact on the safety performance and electrical performance of the battery.
  • the resistance of the negative electrode protective layer needs to be within the range of 500 to 10000 m ⁇ , and more preferably within the range of 1000 to 5000 m ⁇ .
  • the resistance of the negative electrode protection layer can be controlled by selecting conductive particles with different resistivities, controlling the content of conductive particles in the negative electrode protection layer, and other factors.
  • the resistivity of the conductive particles can be controlled to be 50 to 1000 ⁇ cm by adjusting factors such as the type of conductive coating layer material and the mass content of the conductive coating layer in the conductive particles.
  • the average particle size of the conductive particles of the present application is 0.05 to 5 ⁇ m, preferably 0.1 to 1 ⁇ m.
  • the negative electrode protective layer of the present application may also include a small amount of ceramic particles and conductive agents.
  • the ceramic particles can further ensure the anti-puncture performance of the negative electrode protective layer and improve the safety performance of the battery.
  • the conductive agent can increase the conductive network of the negative electrode protective layer and improve the cycle performance of the battery.
  • the ceramic particles can be selected from alumina, and the conductive agent can be selected from carbon nanotubes. The amount of ceramic particles added does not exceed 40wt%, and the amount of conductive agent added does not exceed 2wt%. When the ceramic particles and the amount added exceed the above range, although the battery can obtain higher safety performance, the conductive performance will also decrease.
  • the amount of conductive agent added exceeds the above range, the battery conductivity is improved, but the conductive agent particles are easier to agglomerate and are not conducive to obtaining the best safety performance.
  • the specific amount of conductive agent and ceramic particles added can be adjusted according to actual needs.
  • the thickness of the negative electrode protective layer can be set to 1 to 10 ⁇ m, preferably 2 to 5 ⁇ m.
  • FIG1 is a schematic diagram of the structure of a negative electrode sheet according to an embodiment of the present application.
  • the negative electrode sheet of the present application includes a negative electrode current collector 101, a negative electrode active layer 102 and a negative electrode protective layer 103 stacked in sequence.
  • the negative electrode active layer 102 is disposed on the surface of the negative electrode current collector 101
  • the negative electrode protection layer 103 is disposed on the functional surface of the negative electrode active layer 102 away from the negative electrode current collector 101 .
  • the peeling force between the negative electrode protection layer 103 and the negative electrode active layer 102 is greater than the peeling force between the negative electrode active layer 102 and the negative electrode collector 101, the possibility of the positive electrode collector contacting the negative electrode active layer and causing a battery short circuit can be further reduced.
  • the peeling force between the negative electrode protection layer and the negative electrode active layer can be greater than the peeling force between the negative electrode active layer and the negative electrode current collector by controlling the content of the binder in the negative electrode protection layer to be greater than the content of the binder in the negative electrode active layer.
  • the peeling force between the negative electrode protective layer and the negative electrode active layer can be greater than the peeling force between the negative electrode active layer and the negative electrode current collector by selecting a binder with relatively stronger bonding force to be added to the negative electrode protective layer and a binder with relatively weaker bonding force to be added to the negative electrode active layer.
  • the negative electrode sheet of the present application can also be prepared by conventional technical means in the field.
  • the raw materials constituting the negative electrode protective layer can be uniformly dispersed in a solvent to obtain a negative electrode protective layer slurry
  • the raw materials constituting the negative electrode active layer can be uniformly dispersed in a solvent to obtain a negative electrode active layer slurry
  • the negative electrode active layer slurry is coated on at least one functional surface of the negative electrode collector, and the negative electrode active layer is obtained after drying, and then the negative electrode protective layer slurry is coated on the negative electrode active layer, and dried to obtain a negative electrode sheet that meets the requirements of the present application.
  • the present application does not specifically limit the coating method, and any coating method such as gravure coating, extrusion coating, spraying, screen printing, etc. can be used to coat the negative electrode protective layer slurry and the negative electrode active layer slurry.
  • the second aspect of the present application provides a lithium-ion battery, which includes the negative electrode sheet provided in the first aspect of the present application.
  • the lithium-ion battery of the present application also includes a diaphragm, a positive electrode sheet and an electrolyte.
  • the composition of the positive electrode sheet can refer to the conventional positive electrode sheet in the art, and the diaphragm can also adopt the diaphragm conventionally used in the art, such as PP film, PE film, etc.
  • the lithium-ion battery of the present application can be prepared by conventional methods in the art. Specifically, the positive electrode sheet, the separator and the negative electrode sheet can be stacked in sequence, and then a battery cell can be obtained through a stacking or winding process, and then the above-mentioned lithium-ion battery can be obtained through baking, liquid injection, formation, packaging and other processes.
  • the negative electrode sheet of the present application is provided with a negative electrode protective layer including conductive particles and an adhesive on the surface of the negative electrode active layer, wherein the conductive particles are inorganic fillers with a conductive coating layer, and the inorganic fillers have the characteristics of high mechanical strength, good stability, and good heat resistance.
  • the inorganic filler can well protect the negative electrode active layer, making it difficult to be exposed, reducing the probability of short circuit caused by contact between the positive electrode collector and the negative electrode active layer, and improving the safety performance of the battery.
  • the excellent dispersibility of the inorganic filler itself also makes the conductive particles have good dispersibility, so that the negative electrode protective layer is distributed with a wide conductive network, thereby enabling the battery to have excellent safety performance while having good cycle performance.
  • the lithium-ion battery of the present application because it includes the above-mentioned negative electrode sheet, also has excellent safety performance and good cycle performance.
  • FIG. 1 is a schematic diagram of the structure of a negative electrode sheet according to an embodiment of the present application.
  • the doping amount of antimony element in ATO used in the following examples and comparative examples is 15%.
  • ATO-coated TiO2 90 wt% ATO-coated TiO2 was used as conductive particles (ATO accounted for 2 wt% of the conductive particles) and 10 wt% PVDF were mixed, NMP was added, and a negative electrode protective layer slurry with a solid content of 40% was obtained after stirring;
  • the average particle size of ATO-coated TiO2 is 0.4 ⁇ m.
  • step 3 coating the negative electrode active layer slurry obtained in step 1) on the upper and lower surfaces of a copper foil (thickness of 5 ⁇ m) by an extrusion coating process, and drying to obtain a negative electrode active layer; then coating the negative electrode protective layer slurry obtained in step 2) on the surface of the negative electrode active layer, and drying to obtain a negative electrode sheet;
  • the negative electrode sheet is rolled using a roller press to roll the single-sided thickness of the negative electrode protective layer to 3 ⁇ m, and then the negative electrode sheet is cut using a slitting machine. Finally, the negative electrode tabs are welded on the negative electrode sheet and protective tape is affixed.
  • step 2) coating the positive electrode active layer slurry obtained in step 1) on the upper and lower surfaces of an aluminum foil (thickness of 9 ⁇ m) by extrusion coating, and drying to obtain a positive electrode sheet;
  • the positive electrode sheet is rolled and cut using a roller press and a slitting machine respectively, and finally the positive electrode ear is welded on the positive electrode sheet and a protective tape is affixed.
  • the battery cell is sealed for a second time and folded to obtain the lithium-ion battery of this embodiment.
  • the steps for preparing the negative electrode sheet and the lithium-ion battery in this embodiment are basically the same as those in Embodiment 1, except that:
  • step 2) the ATO-coated TiO2 in Example 1 is replaced with ATO-coated Al2O3;
  • the negative electrode sheet is replaced with the negative electrode sheet prepared in this embodiment.
  • the steps for preparing the negative electrode sheet and the lithium-ion battery in this embodiment are basically the same as those in Embodiment 1, except that:
  • step 2) the ATO-coated TiO2 in Example 1 is replaced with SnO2-coated ZnO;
  • the negative electrode sheet is replaced with the negative electrode sheet prepared in this embodiment.
  • the steps for preparing the negative electrode sheet and the lithium-ion battery in this embodiment are basically the same as those in Embodiment 1, except that:
  • step 2) the ATO-coated TiO2 in Example 1 is replaced with ATO-coated SiO2;
  • the negative electrode sheet is replaced with the negative electrode sheet prepared in this embodiment.
  • the steps for preparing the negative electrode sheet and the lithium-ion battery in this embodiment are basically the same as those in Embodiment 1, except that:
  • step 2) the ATO-coated TiO2 in Example 1 is replaced with ATO-coated MnO2;
  • the negative electrode sheet is replaced with the negative electrode sheet prepared in this embodiment.
  • the steps for preparing the negative electrode sheet and the lithium-ion battery in this embodiment are basically the same as those in Embodiment 1, except that:
  • step 2) the ATO-coated TiO2 in Example 1 is replaced with ATO-coated boehmite;
  • the negative electrode sheet is replaced with the negative electrode sheet prepared in this embodiment.
  • the steps for preparing the negative electrode sheet and the lithium-ion battery in this embodiment are basically the same as those in Embodiment 1, except that:
  • step 2) the ATO-coated TiO2 in Example 1 is replaced with carbon black-coated TiO2;
  • the negative electrode sheet is replaced with the negative electrode sheet prepared in this embodiment.
  • the steps for preparing the negative electrode sheet and the lithium-ion battery in this embodiment are basically the same as those in Embodiment 1, except that:
  • step 2) the 90wt% ATO-coated TiO2 and 10wt% PVDF in Example 1 are replaced with 95wt% ATO-coated TiO2 and 5wt% PVDF;
  • the negative electrode sheet is replaced with the negative electrode sheet prepared in this embodiment.
  • the steps for preparing the negative electrode sheet and the lithium-ion battery in this embodiment are basically the same as those in Embodiment 1, except that:
  • step 2 the 90 wt % ATO-coated TiO2 and 10 wt % PVDF in Example 1 are replaced with 80 wt % ATO-coated TiO2 and 20 wt % PVDF;
  • the negative electrode sheet is replaced with the negative electrode sheet prepared in this embodiment.
  • the steps for preparing the negative electrode sheet and the lithium-ion battery in this embodiment are basically the same as those in Embodiment 1, except that:
  • step 2 the 90 wt % ATO-coated TiO2 and 10 wt % PVDF in Example 1 are replaced with 70 wt % ATO-coated TiO2 and 30 wt % PVDF;
  • the negative electrode sheet is replaced with the negative electrode sheet prepared in this embodiment.
  • the steps for preparing the negative electrode sheet and the lithium-ion battery in this embodiment are basically the same as those in Embodiment 1, except that:
  • step 2) the 90wt% ATO-coated TiO2 and 10wt% PVDF in Example 1 are replaced with 40wt% ATO-coated TiO2, 50% Al2O3 and 10wt% PVDF;
  • the negative electrode sheet is replaced with the negative electrode sheet prepared in this embodiment.
  • the steps for preparing the negative electrode sheet and the lithium-ion battery in this embodiment are basically the same as those in Embodiment 1, except that:
  • the thickness of the negative electrode protective layer of the prepared negative electrode sheet is 1 ⁇ m;
  • the negative electrode sheet is replaced with the negative electrode sheet prepared in this embodiment.
  • the steps for preparing the negative electrode sheet and the lithium-ion battery in this embodiment are basically the same as those in Embodiment 1, except that:
  • the thickness of the negative electrode protective layer of the prepared negative electrode sheet is 2 ⁇ m;
  • the negative electrode sheet is replaced with the negative electrode sheet prepared in this embodiment.
  • the steps for preparing the negative electrode sheet and the lithium-ion battery in this embodiment are basically the same as those in Embodiment 1, except that:
  • the thickness of the negative electrode protective layer of the prepared negative electrode sheet is 4 ⁇ m;
  • the negative electrode sheet is replaced with the negative electrode sheet prepared in this embodiment.
  • the steps for preparing the negative electrode sheet and the lithium-ion battery in this embodiment are basically the same as those in Embodiment 1, except that:
  • the thickness of the negative electrode protective layer of the prepared negative electrode sheet is 5 ⁇ m;
  • the negative electrode sheet is replaced with the negative electrode sheet prepared in this embodiment.
  • the steps for preparing the negative electrode sheet and the lithium-ion battery of this embodiment are basically the same as those of Embodiment 1, except that: in the preparation of the negative electrode sheet, the thickness of the negative electrode protective layer of the prepared negative electrode sheet is 0.5 ⁇ m;
  • the negative electrode sheet is replaced with the negative electrode sheet prepared in this embodiment.
  • the steps for preparing the negative electrode sheet and the lithium-ion battery in this embodiment are basically the same as those in Embodiment 1, except that:
  • the thickness of the negative electrode protective layer of the prepared negative electrode sheet is 15 ⁇ m;
  • the negative electrode sheet is replaced with the negative electrode sheet prepared in this embodiment.
  • the steps for preparing the negative electrode sheet and the lithium-ion battery in this embodiment are basically the same as those in Embodiment 1, except that:
  • the conductive coating of the conductive particles in the negative electrode protective layer accounts for 0.5wt%
  • the negative electrode sheet is replaced with the negative electrode sheet prepared in this embodiment.
  • the steps for preparing the negative electrode sheet and the lithium-ion battery in this embodiment are basically the same as those in Embodiment 1, except that:
  • the conductive coating of the conductive particles in the negative electrode protective layer accounts for 20wt%
  • the negative electrode sheet is replaced with the negative electrode sheet prepared in this embodiment.
  • the steps for preparing the negative electrode sheet and the lithium-ion battery in this embodiment are basically the same as those in Embodiment 1, except that:
  • the conductive coating of the conductive particles in the negative electrode protective layer accounts for 0.2wt%
  • the negative electrode sheet is replaced with the negative electrode sheet prepared in this embodiment.
  • the steps for preparing the negative electrode sheet and the lithium-ion battery in this embodiment are basically the same as those in Embodiment 1, except that:
  • the conductive coating of the conductive particles in the negative electrode protective layer accounts for 40wt%
  • the negative electrode sheet is replaced with the negative electrode sheet prepared in this embodiment.
  • the steps for preparing the negative electrode sheet and the lithium-ion battery in this embodiment are basically the same as those in Example 15, except that:
  • the average particle size of the conductive particles in the negative electrode protective layer is 1 ⁇ m;
  • the negative electrode sheet is replaced with the negative electrode sheet prepared in this embodiment.
  • the steps for preparing the negative electrode sheet and the lithium-ion battery in this embodiment are basically the same as those in Example 15, except that:
  • the average particle size of the conductive particles in the negative electrode protective layer is 5 ⁇ m;
  • the negative electrode sheet is replaced with the negative electrode sheet prepared in this embodiment.
  • the preparation steps of the negative electrode sheet and the lithium-ion battery of this embodiment are basically the same as those of Embodiment 15, except that:
  • the average particle size of the conductive particles in the negative electrode protective layer is 10 ⁇ m;
  • the negative electrode sheet is replaced with the negative electrode sheet prepared in this embodiment.
  • step 2) coating the negative electrode active layer slurry obtained in step 1) on the upper and lower surfaces of a copper foil (5 ⁇ m) by extrusion coating, and drying to obtain a negative electrode sheet;
  • the preparation steps of the lithium-ion battery of this comparative example are basically the same as those of Example 1, except that the negative electrode sheet is replaced with the negative electrode sheet prepared in this comparative example.
  • the preparation steps of the negative electrode sheet and the lithium-ion battery of this comparative example are basically the same as those of Example 1, except that:
  • the 90wt% ATO-coated TiO2 and 10wt% PVDF in Example 1 were replaced with 95wt% TiO2 and 5wt% PVDF;
  • the negative electrode sheet is replaced with the negative electrode sheet prepared in this comparative example.
  • the preparation steps of the negative electrode sheet and the lithium-ion battery of this comparative example are basically the same as those of Example 7, except that:
  • Example 7 In the preparation of the negative electrode sheet, the 90wt% carbon black-coated TiO2 and 10wt% in Example 7 were replaced with 89.55wt% TiO2+0.45% carbon black+10wt% PVDF.
  • the preparation steps of the negative electrode sheet and the lithium-ion battery of this comparative example are basically the same as those of Example 1, except that:
  • Example 1 In the preparation of the negative electrode sheet, the 90 wt % ATO-coated TiO 2 and 10 wt % PVDF in Example 1 were replaced with 88.2 wt % TiO 2 + 1.8 % ATO + 10 wt % PVDF.
  • the resistance of the negative electrode sheet protective layer of the above embodiments and comparative examples was tested.
  • the lithium-ion batteries of the above embodiments and comparative examples were tested for needle penetration rate, screw extrusion pass rate, capacity retention rate, and energy density.
  • the test methods are as follows:
  • Test method Fully charge the lithium-ion battery, then place it on the test bench of the needle puncture test equipment, and pierce the battery from the middle of the battery at a speed of 100mm/s with a tungsten steel needle with a diameter of 3mm and a needle tip length of 3.62mm. If the battery does not catch fire or explode, the test is considered to have passed.
  • the number of passes/the number of tests is the needle puncture pass rate, and the number of tests is 30.
  • Test method fully charge the lithium-ion battery, then put it on the test bench of the extrusion equipment, put the M2*4 (screw diameter is 2mm, screw length is 4mm) screw in the middle of the battery, then start the extrusion equipment, the extrusion plate presses down at a speed of 100mm/s, and the test is stopped when the extrusion force reaches 13KN.
  • the battery is considered to have passed the test if it does not catch fire or explode.
  • the number of passes/tested number is the screw test pass rate, and the number of tests is 30.
  • Test method At 25°C, charge and discharge the lithium-ion battery at a rate of 1.5C charge/0.5C discharge, and record the discharge capacity Q2 of the 500th charge and discharge and the discharge capacity Q1 of the first charge and discharge.
  • the capacity retention rate Q2/Q1 ⁇ 100%.
  • Example 1 By comparing Example 1 with Comparative Example 1, it can be seen that the addition of a negative electrode protective layer can significantly improve the safety performance of the battery; by comparing Example 1 with Comparative Example 2, it can be seen that when there is no conductive component in the negative electrode protective layer, the capacity retention rate of the battery is significantly deteriorated; from the comparison between Example 1 and Comparative Example 4, and Example 7 and Comparative Example 3, it can be seen that by changing the conductive agent and inorganic filler in the conductive particles from coating to mixing, the electrode resistance increases and the cycle performance of the battery deteriorates.
  • Example 2 Comparing Example 1 with Examples 12 to 17, it can be seen that the thickness of the negative electrode protective layer has an impact on the energy density of the battery. The greater the thickness of the negative electrode protective layer, the lower the battery energy density, and the smaller the thickness of the negative electrode protective layer, the higher the battery energy density.
  • Example 1 By comparing Example 1 and Examples 18 to 21, it can be seen that as the mass ratio of the conductive coating layer in the conductive particles increases, the needle puncture pass rate and the screw extrusion pass rate of the battery will slightly decrease, and the safety performance of the battery will decrease.
  • Example 1 By comparing Example 1 and Examples 22 to 24, it can be seen that the average particle size of the conductive particles will affect the safety performance of the battery. If the average particle size of the conductive particles is too large, the needle puncture pass rate and screw extrusion pass rate of the battery will be significantly reduced, and the safety performance of the battery will deteriorate.

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  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Battery Electrode And Active Subsutance (AREA)
  • Secondary Cells (AREA)

Abstract

L'invention concerne une feuille d'électrode négative et une batterie au lithium-ion. La feuille d'électrode négative comprend un collecteur de courant d'électrode négative, une couche de protection d'électrode négative et une couche active d'électrode négative disposée entre le collecteur de courant d'électrode négative et la couche de protection d'électrode négative ; la couche de protection d'électrode négative comprend des particules conductrices et un adhésif ; et les particules conductrices sont des charges inorganiques comportant des couches de revêtement conductrices sur leurs surfaces. Selon la feuille d'électrode négative, en fournissant une couche de protection d'électrode négative, un contact de court-circuit entre un collecteur de courant d'électrode positive et une couche active d'électrode négative pendant l'abus mécanique d'une batterie au lithium-ion peut être évité ; de plus, un réseau conducteur étendu est en outre disposé dans la couche de protection d'électrode négative, de telle sorte que la batterie au lithium-ion peut avoir d'excellentes performances de sécurité et une excellente performance de cycle.
PCT/CN2023/113334 2022-10-24 2023-08-16 Feuille d'électrode négative et batterie au lithium-ion WO2024087817A1 (fr)

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Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102800841A (zh) * 2012-08-08 2012-11-28 深圳清华大学研究院 负极片、锂离子电池及其制备方法
CN109888200A (zh) * 2018-12-29 2019-06-14 深圳市卓能新能源股份有限公司 电池负极涂层、电池负极片及其制造方法、锂离子电池
CN109888199A (zh) * 2018-12-29 2019-06-14 深圳市卓能新能源股份有限公司 电池负极涂层、电池负极片及其制造方法、锂离子电池
CN112271271A (zh) * 2020-10-15 2021-01-26 广州汽车集团股份有限公司 负极片及制备方法、锂离子电芯、锂离子电池包及其应用
CN112786832A (zh) * 2021-01-25 2021-05-11 湖南立方新能源科技有限责任公司 一种负极片及锂离子电池
CN114122318A (zh) * 2021-11-19 2022-03-01 湖北亿纬动力有限公司 一种负极极片及其制备方法和应用
CN114792808A (zh) * 2021-01-25 2022-07-26 华为技术有限公司 锂离子电池的负极片、锂离子电池和电子设备
CN114927642A (zh) * 2021-01-28 2022-08-19 广汽埃安新能源汽车有限公司 一种负极片及制备方法和锂离子电池
WO2022178748A1 (fr) * 2021-02-25 2022-09-01 宁德新能源科技有限公司 Matériau actif d'électrode négative, élément d'électrode négative, appareil électrochimique et appareil électronique

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102800841A (zh) * 2012-08-08 2012-11-28 深圳清华大学研究院 负极片、锂离子电池及其制备方法
CN109888200A (zh) * 2018-12-29 2019-06-14 深圳市卓能新能源股份有限公司 电池负极涂层、电池负极片及其制造方法、锂离子电池
CN109888199A (zh) * 2018-12-29 2019-06-14 深圳市卓能新能源股份有限公司 电池负极涂层、电池负极片及其制造方法、锂离子电池
CN112271271A (zh) * 2020-10-15 2021-01-26 广州汽车集团股份有限公司 负极片及制备方法、锂离子电芯、锂离子电池包及其应用
CN112786832A (zh) * 2021-01-25 2021-05-11 湖南立方新能源科技有限责任公司 一种负极片及锂离子电池
CN114792808A (zh) * 2021-01-25 2022-07-26 华为技术有限公司 锂离子电池的负极片、锂离子电池和电子设备
WO2022156459A1 (fr) * 2021-01-25 2022-07-28 华为技术有限公司 Feuille d'électrode négative de batterie au lithium-ion, batterie au lithium-ion et dispositif électronique
CN114927642A (zh) * 2021-01-28 2022-08-19 广汽埃安新能源汽车有限公司 一种负极片及制备方法和锂离子电池
WO2022178748A1 (fr) * 2021-02-25 2022-09-01 宁德新能源科技有限公司 Matériau actif d'électrode négative, élément d'électrode négative, appareil électrochimique et appareil électronique
CN114122318A (zh) * 2021-11-19 2022-03-01 湖北亿纬动力有限公司 一种负极极片及其制备方法和应用

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