Electrode plate and electrochemical device

Patent metadata

Field	Value
Publication number	US-12525615-B2
Application number	US-201917059503-A
Country	US
Kind code	B2
Filing date	Nov 20, 2019
Priority date	Dec 29, 2018
Publication date	Jan 13, 2026
Grant date	Jan 13, 2026

Abstract

The electrode plate according to the present application includes a current collector and an electrode active material layer disposed on at least one surface of the current collector, wherein the current collector includes a support layer and a conductive layer, the conductive layer has a single-sided thickness D2 satisfying: 30 nm≤D2≤3 μm; and the conductive agent is unevenly distributed in the electrode active material layer in a thickness direction of the electrode active material layer, in which the weight percentage of the conductive agent in the inner region of the electrode active material layer is higher than the weight percentage content of the conductive agent in the outer region of the electrode active material layer, and the binder in the inner region of the electrode active material layer includes a water-dispersible binder.

First claim

The invention claimed is:

1 . An electrochemical device comprising a positive electrode plate, a negative electrode plate, a separator and an electrolyte, wherein the positive electrode plate or the negative electrode plate is an electrode plate comprising a current collector and an electrode active material layer disposed on at least one surface of the current collector, wherein
the current collector comprises a support layer and a conductive layer disposed on at least one surface of the support layer, the conductive layer has a single-sided thickness D2 that satisfies: 30 nm≤D2≤3 μm; and the electrode active material layer comprises an electrode active material, a binder and a conductive agent; and the electrode active material layer is divided into two regions, an inner region and an outer region, in a thickness direction of the electrode active material layer; and the conductive agent is unevenly distributed in the electrode active material layer in a thickness direction of the electrode active material layer, in which the weight percentage of the conductive agent in the inner region of the electrode active material layer is higher than the weight percentage content of the conductive agent in the outer region of the electrode active material layer based on the total weight of the electrode active material layer, and the binder in the inner region of the electrode active material layer comprises a water-dispersible binder; and the conductive layer is further provided with a protective layer on its surface, the protective A layer being provided on both surfaces of the conductive layers of the current collector, provided on the surface of the conductive layer facing away from the support layer, and provided on the surface of the conductive layer facing toward the support layer; and the protective layer has a thickness D3 that satisfies: D3≤1/10D2 and 1 nm≤D3≤200 nm; and the protective layer provided on the surface of the conductive laver facing toward the support layer is made of a nickel oxide; and the conductive layer is a metal conductive layer and the metal conductive layer comprises a material of aluminum; and the support layer comprises a material selected from at least one of insulating polymer materials, insulating polymer composite materials, conductive polymer materials, and conductive polymer composite materials.

2 . The electrochemical device according to claim 1 , wherein
the support layer has a thickness D1 that satisfies: 1 μm≤D1≤30 μm; or the support layer has a normal temperature Young's modulus that satisfies: 20 GPa≥E≥4 GPa; or there are cracks in the conductive layer.

3 . The electrochemical device according to claim 1 , wherein the conductive layer has a single-sided thickness D2 that satisfies: 300 nm≤D2≤2 μm.

4 . The electrochemical device according to claim 1 , wherein
the conductive agent is at least one of a conductive carbon material and a metal material in which the conductive carbon material is selected from at least one of zero-dimensional conductive carbon, one-dimensional conductive carbon, two-dimensional conductive carbon, and three-dimensional conductive carbon; the metal material is selected from at least one of aluminum powder, iron powder and silver powder; or the binder is selected from at least one of styrene butadiene rubber, oil-dispersible polyvinylidene fluoride (PVDF), polyvinylidene fluoride copolymer, sodium carboxymethyl cellulose, polystyrene, polyacrylic acid, polytetrafluoroethylene, polyacrylonitrile, polyimide, water-dispersible PVDF, polyurethane, polyvinyl alcohol, polyacrylates, polyacrylic acid-polyacrylonitrile copolymer, and polyacrylate-polyacrylonitrile copolymers; or the water-dispersible binder is selected from at least one of water-dispersible PVDF, polyacrylic acid, polyurethane, polyvinyl alcohol, polyacrylates, polyacrylic acid-polyacrylonitrile copolymer, and polyacrylates-polyacrylonitrile copolymer.

5 . The electrochemical device according to claim 1 , wherein the conductive agent in the inner region comprises a one-dimensional conductive carbon material or a two-dimensional conductive carbon material.

6 . The electrochemical device according to claim 5 , wherein the one-dimensional conductive carbon material or the two-dimensional conductive carbon material in the inner region constitute 1 wt %-50 wt % of the conductive agent in the inner region.

7 . The electrochemical device according to claim 5 , wherein the two-dimensional conductive carbon material has a particle size D50 of 0.01 to 0.1 μm.

8 . The electrochemical device according to claim 1 , wherein the conductive agent is present in a weight percentage of 10% to 99% and the binder is present in a weight percentage of 1% to 90%, based on the total weight of the electrode active material layer at the inner region.

9 . The electrochemical device according to claim 1 , wherein the weight percentage of the binder in the inner region is higher than the weight percentage content of the binder in the outer region.

10 . The electrochemical device according to claim 1 , wherein the inner region has a thickness H of 0.1 to 5 μm.

11 . The electrochemical device according to claim 10 , wherein a ratio of H/D2 is 0.5:1 to 5:1.

12 . The electrochemical device according to claim 1 , wherein the electrode active material has an average particle diameter D50 of 5-15 μm.

13 . A battery module characterized in comprising the electrochemical device as claimed in claim 1 .

14 . An apparatus characterized in comprising the electrochemical device as claimed in claim 1 , wherein the electrochemical device is used as a power source of the apparatus; the apparatus comprising electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, electric ships, or energy storage systems.

15 . The electrochemical device according to claim 1 , wherein the insulating polymer material is selected from at least one of polyamide, polyterephthalate, polyimide, polyethylene, polypropylene, polystyrene, polyvinyl chloride, aramid, acrylonitrile-butadiene-styrene copolymer, polybutylene terephthalate, poly p-phenylene terephthalamide, polyoxymethylene, epoxy resin, phenolic resin, polytetrafluoroethylene, polyphenyl sulfide, polyvinylidene fluoride, silicone rubber, polycarbonate, cellulose and its derivatives, starch and its derivatives, protein and its derivatives, polyvinyl alcohol and its cross-linked products, polyethylene glycol and its cross-linked products.

16 . The electrochemical device according to claim 1 , wherein the insulating polymer composite material is selected from composite materials formed by insulating polymer materials and inorganic materials in which the inorganic material is at least one of a ceramic material, a glass material, and a ceramic composite material.

17 . The electrochemical device according to claim 1 , wherein in the inner region, the water-dispersible constitutes 30% to 100% of the total weight of the binder in the inner region.

Assignees

• Contemporary Amperex Technology Hong Kong Ltd

Inventors

• Li Jing
• Xue Qingrui
• Zhang Zige
• Li Wei
• Yang Xianwei

Classifications

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title

• H01M2004/028

  Positive electrodes · CPC title

• H01M2004/027

  Negative electrodes · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/625

  Carbon or graphite · CPC title