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EP-4742318-A1 - COMPOSITE MATERIAL AND PREPARATION METHOD THEREFOR, POSITIVE ELECTRODE SHEET, BATTERY CELL, BATTERY, AND ELECTRIC DEVICE

EP4742318A1EP 4742318 A1EP4742318 A1EP 4742318A1EP-4742318-A1

Abstract

A composite material and a preparation method therefor, a positive electrode plate, a cell, a battery, and an electric device belong to the field of battery technologies. A composite material includes a lithium-containing compound, a catalyst, and a carbon material. The carbon material has a hollow tubular structure, and the lithium-containing compound and the catalyst are arranged in the tubular structure. The lithium-containing compound includes lithium, carbon, and oxygen. The catalyst includes at least one of a transition metal oxide, a transition metal carbide, or a transition metal nitride. Technical solutions of embodiments of this application can improve a capacity of a cell.

Inventors

  • WANG, Bangrun
  • ZHANG, Xingwen
  • LIU, Na

Assignees

  • Contemporary Amperex Technology Co., Limited

Dates

Publication Date
20260513
Application Date
20231123

Claims (20)

  1. A composite material, comprising: a lithium-containing compound, a catalyst, and a carbon material, wherein the carbon material has a hollow tubular structure, and the lithium-containing compound and the catalyst are arranged in the tubular structure; the lithium-containing compound comprises lithium, carbon, and oxygen; and the catalyst comprises at least one of a transition metal oxide, a transition metal carbide, or a transition metal nitride.
  2. The composite material according to claim 1, wherein the lithium-containing compound and the catalyst are arranged on an inner wall of the tubular structure.
  3. The composite material according to claim 1 or 2, wherein at least a part of the catalyst is located on a surface of the lithium-containing compound.
  4. The composite material according to any one of claims 1 to 3, wherein a chemical formula of the lithium-containing compound is Li 2 C x O y , wherein 1≤x≤4, and 3≤y≤6; and optionally, the lithium-containing compound comprises at least one of Li 2 C 2 O 4 , Li 2 CO 3 , Li 2 C 4 O 4 , Li 2 C 3 O 5 , or Li 2 C 4 O 6 .
  5. The composite material according to any one of claims 1 to 4, wherein a chemical formula of the transition metal oxide is M α O β , wherein 0<α≤3, 0<β≤5, and M comprises at least one of Ni, Co, Fe, Mn, V, Cr, Cu, or Ti; and optionally, M α O β comprises at least one of NiO, Co 3 O 4 , Fe 2 O 3 , MoO 3 , or V 2 O 5 .
  6. The composite material according to any one of claims 1 to 5, wherein the transition metal carbide comprises at least one of molybdenum carbide, vanadium carbide, tungsten carbide, titanium carbide, cobalt carbide, iron carbide, or nickel carbide; and/or the transition metal nitride comprises at least one of molybdenum nitride, vanadium nitride, titanium nitride, manganese nitride, cobalt nitride, iron nitride, or nickel nitride.
  7. The composite material according to any one of claims 1 to 6, wherein based on a total mass of the composite material, a mass content A of the carbon material satisfies: 1wt%≤A≤40wt%; and optionally, A satisfies: 2wt%≤A≤25wt%.
  8. The composite material according to any one of claims 1 to 7, wherein based on a total mass of the composite material, a mass content B of the catalyst satisfies: 0.1wt%≤B≤20wt%; and optionally, B satisfies: 0.5wt%≤B≤10wt%.
  9. The composite material according to any one of claims 1 to 8, wherein based on a total mass of the composite material, a mass content C of the lithium-containing compound satisfies: 45wt%≤B≤98.9wt%; and optionally, C satisfies: 70wt%≤B≤85wt%.
  10. The composite material according to any one of claims 1 to 9, wherein an aspect ratio E of the carbon material satisfies: 100:1≤E≤3000:1; optionally, E satisfies: 200:1≤E≤2000:1.
  11. The composite material according to any one of claims 1 to 10, wherein in the composite material, a decomposition voltage V1 of the lithium-containing compound satisfies: V1<4.8 V; and optionally, V1 satisfies: V1<4.4 V.
  12. The composite material according to any one of claims 1 to 11, wherein a resistivity P of the composite material satisfies: 0.2 Ω·cm<P<101 Ω·cm; and optionally, P satisfies: 0.2 Ω·cm<P<5.5 Ω·cm.
  13. The composite material according to any one of claims 1 to 12, wherein an average volume particle size Dv 1 50 of the lithium-containing compound is greater than an average volume particle size Dv 2 50 of the catalyst; and optionally, the average volume particle size Dv 1 50 of the lithium-containing compound satisfies: 100 nm≤Dv 1 50≤1000 nm, and the average volume particle size Dv 2 50 of the catalyst satisfies: 50 nm≤Dv 2 50≤500 nm.
  14. A preparation method for the composite material according to any one of claims 1 to 13, comprising: mixing a lithium-containing compound and a catalyst to obtain a mixed material of the lithium-containing compound and the catalyst, wherein the catalyst comprises at least one of a transition metal oxide, a transition metal carbide, or a transition metal nitride, and the lithium-containing compound comprises lithium, carbon, and oxygen; adding the mixed material of the lithium-containing compound and the catalyst into a polymer material-containing slurry, to obtain an electrospinning stock solution; performing electrospinning on the electrospinning stock solution, to obtain a precursor; and performing calcination of the precursor in an inert atmosphere to obtain the composite material.
  15. The method according to claim 14, wherein a chemical formula of the lithium-containing compound is Li 2 C x O y , wherein 1≤x≤4, and 3≤y≤6; and optionally, the lithium-containing compound comprises at least one of Li 2 C 2 O 4 , Li 2 CO 3 , Li 2 C 4 O 4 , Li 2 C 3 O 5 , or Li 2 C 4 O 6 .
  16. The method according to claim 14 or 15, wherein a chemical formula of the transition metal oxide is M α O β , wherein 0<α≤3, 0<β≤5, and M comprises at least one of Ni, Co, Fe, Mn, V, Cr, Cu, or Ti; and optionally, M α O β comprises at least one of NiO, Co 3 O 4 , Fe 2 O 3 , MoO 3 , or V 2 O 5 .
  17. The method according to any one of claims 14 to 16, wherein the transition metal carbide comprises at least one of molybdenum carbide, vanadium carbide, tungsten carbide, titanium carbide, cobalt carbide, iron carbide, or nickel carbide; and/or the transition metal nitride comprises at least one of molybdenum nitride, vanadium nitride, titanium nitride, manganese nitride, cobalt nitride, iron nitride, or nickel nitride.
  18. The method according to any one of claims 14 to 17, wherein a solute in the polymer material-containing slurry comprises a polymer material, and a solvent in the polymer material-containing slurry is an organic solvent; and optionally, the organic solvent comprises N,N-dimethylformamide.
  19. The method according to any one of claims 14 to 18, wherein the polymer material comprises at least one of polyvinyl pyrrolidone, polyacrylonitrile, or polyethylene oxide; and optionally, the polymer material comprises polyacrylonitrile.
  20. The method according to claim 18 or 19, wherein a mass ratio D of the polymer material to the N,N-dimethylformamide satisfies: 1:20≤D≤1:1; and optionally, D satisfies: 1:15≤D≤1:2.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to Patent Application No. 202310910441.4, entitled "COMPOSITE MATERIAL AND PREPARATION METHOD THEREFOR, POSITIVE ELECTRODE PLATE, CELL, BATTERY, AND ELECTRIC DEVICE" filed on July 24, 2023, which is incorporated by reference in its entirety. TECHNICAL FIELD This application relates to the field of battery technologies, and in particular, to a composite material and a preparation method therefor, a positive electrode plate, a cell, a battery, and an electric device. BACKGROUND With the increasing severity of environmental pollution, the new energy industry has attracted more and more attention. In the new energy industry, the battery technology is an important factor affecting its development. In the development of battery technologies, various design factors, such as a capacity, an energy density, a cycle life, and reliability, need to be taken into account. In a first charge and discharge process of a cell, a solid electrolyte interface SEI film is produced on a surface of a negative electrode, and the presence of the SEI film consumes a large quantity of lithium ions, affecting a capacity of the cell. Therefore, how to provide a composite material to supplement lithium ions, to improve the capacity of the cell, is a technical problem that needs to be resolved urgently. SUMMARY This application is made in view of the foregoing problems, and an objective thereof is to provide a composite material, to improve a capacity of a cell. To achieve the foregoing objective, this application provides a composite material and a preparation method therefor, a positive electrode plate, a cell, a battery, and an electric device. According to a first aspect, a composite material is provided, including: a lithium-containing compound, a catalyst, and a carbon material, where the carbon material has a hollow tubular structure, and the lithium-containing compound and the catalyst are arranged in the tubular structure; the lithium-containing compound includes lithium, carbon, and oxygen; and the catalyst includes at least one of a transition metal oxide, a transition metal carbide, or a transition metal nitride. In this embodiment of this application, the lithium-containing compound can decompose to produce lithium ions and gas, to supplement lithium ions to the battery. The catalyst may catalyze decomposition of the lithium-containing compound. The carbon material has a hollow tubular structure, and the lithium-containing compound and the catalyst are arranged in the tubular structure, which is conducive to improving the capacity of the battery. Therefore, technical solutions of embodiments of this application can improve the capacity of the cell. In a possible implementation, the lithium-containing compound and the catalyst are arranged on an inner wall of the tubular structure. In this way, the lithium-containing compound and the catalyst can be better arranged in the tubular structure, thereby reducing a risk that the lithium-containing compound and the catalyst escape from the tubular structure when the composite material is short. In a possible implementation, at least a part of the catalyst is located on a surface of the lithium-containing compound, which helps the catalyst to catalyze decomposition of the lithium-containing compound. In a possible implementation, a chemical formula of the lithium-containing compound is Li2CxOy, where 1≤x≤4, and 3≤y≤6; and optionally, the lithium-containing compound includes at least one of Li2C2O4, Li2CO3, Li2C4O4, Li2C3O5, or Li2C4O6. The foregoing lithium-containing compound may decompose into lithium ions and gas (such as carbon monoxide and carbon dioxide) under the action of a voltage and the catalyst, and the lithium ions produced through decomposition may play a role in supplementing lithium ions, which is conducive to improving a capacity of the battery. The gas produced through decomposition does not remain in the positive electrode plate, and performance, such as long-term reliability, of the cell is not affected by residues produced through decomposition. In addition, the foregoing lithium-containing compound has good stability, can stably exist in air and an organic solvent, and is compatible with a film coating process for a positive electrode slurry. In a possible implementation, a chemical formula of the transition metal oxide is MαOβ, where 0<α≤3, 0<β≤5, and M includes at least one of Ni, Co, Fe, Mn, V, Cr, Cu, or Ti; and optionally, MαOβ includes at least one of NiO, Co3O4, Fe2O3, MoO3, or V2O5. The foregoing catalyst can lower a decomposition voltage of the lithium-containing compound, so that the lithium-containing compound decomposes at a lower voltage. In a possible implementation, the transition metal carbide includes at least one of molybdenum carbide, vanadium carbide, tungsten carbide, titanium carbide, cobalt carbide, iron carbide, or nickel carbide; and/or the transition metal nitride in