Electrode and lithium-ion battery

1. An electrode, comprising:

a current collector;

a first active material layer, comprising a first active material; and

a second active material layer, comprising a second active material;

wherein the first active material layer is arranged between the current collector and the second active material layer, the first active material layer is formed on at least one surface of the current collector, and a ratio of an average particle size of the second active material to an average particle size of the first active material is from 1:1 to 40:1, wherein a particle size of 90% accumulative volume of the first active material is less than 40 μm.

2. The electrode according to claim 1 , wherein the first active material has an average particle size in a range of 0.2 μm to 15 μm.

3. The electrode according to claim 1 , wherein the first active material layer has a thickness of 2 μm to 30 μm.

4. The electrode according to claim 1 , wherein the second active material layer has a thickness equal to or more than 30 μm.

5. The electrode according to claim 1 , wherein the first active material comprises one of lithium cobaltate, lithium manganate, lithium nickelate, lithium nickel cobalt manganese oxide, lithium iron phosphate, lithium iron manganese phosphate, lithium vanadium phosphate, lithium vanadyl phosphate, lithium-rich manganese-based materials, lithium nickel cobalt aluminate and lithium titanate, and combinations thereof.

6. The electrode according to claim 1 , wherein the second active material comprises one of lithium cobaltate, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium-rich manganese-based material, lithium iron phosphate, and combinations thereof.

7. The electrode according to claim 1 , wherein the first active material comprises one of artificial graphite, natural graphite, mesocarbon microbeads, soft carbon, hard carbon, silicon, silicon carbide, lithium titanate, and combinations thereof.

8. The electrode according to claim 1 , wherein each of the first active material layer and the second active material layer further comprises a binder, and the binder comprises one of polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polyimide, polyacrylonitrile, polyacrylates, polyacrylic acids, polyacrylic acid salt, carboxymethylcellulose sodium, polyethylene pyrrolidone, polyvinyl ether, polymethyl methacrylate, polytetrafluoroethylene, polyhexafluoropropylene and styrene butadiene rubber, and combinations thereof.

9. A lithium-ion battery comprising an electrode, wherein the electrode comprises:

a current collector;

a first active material layer, comprising a first active material; and

a second active material layer, comprising a second active material;

wherein the first active material layer is arranged between the current collector and the second active material layer, the first active material layer is formed on at least one surface of the current collector, and a ratio of an average particle size of the second active material to an average particle size of the first active material is from 1:1 to 40:1, wherein a particle size of 90% accumulative volume of the first active material is less than 40 μm.

10. The lithium-ion battery according to claim 9 , wherein the first active material has an average particle size in a range of 0.2 μm to 15 μm.

11. The lithium-ion battery according to claim 9 , wherein the first active material layer has a thickness of 2 μm to 30 μm.

12. The lithium-ion battery according to claim 9 , wherein the second active material layer has a thickness equal to more than 30 μm.

13. The lithium-ion battery according to claim 9 , wherein the first active material comprises one of lithium cobaltate, lithium manganate, lithium nickelate, lithium nickel cobalt manganese oxide, lithium iron phosphate, lithium iron manganese phosphate, lithium vanadium phosphate, lithium vanadyl phosphate, lithium-rich manganese-based materials, lithium nickel cobalt alum inate and lithium titanate, and combinations thereof.

14. The lithium-ion battery according to claim 9 , wherein the second active material comprises one of lithium cobaltate, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium-rich manganese-based material, lithium iron phosphate, and combinations thereof.

15. The lithium-ion battery according to claim 9 , wherein the first active material comprises one of artificial graphite, natural graphite, mesocarbon microbeads, soft carbon, hard carbon, silicon, silicon carbide, lithium titanate, and combinations thereof.

16. The lithium-ion battery according to claim 9 , wherein each of the first active material layer and the second active material layer further comprises a binder, and the binder comprises one polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polyimide, polyacrylonitrile, polyacrylates, polyacrylic acids, polyacrylic acid salt, carboxymethylcellulose sodium, polyethylene pyrrolidone, polyvinyl ether, polymethyl methacrylate, polytetrafluoroethylene, polyhexafluoropropylene and styrene butadiene rubber, and combinations thereof.

17. The electrode according to claim 3 , wherein the first active material layer has a thickness of 7 μm to 30 μm.

18. The lithium-ion battery according to claim 11 , wherein the first active material layer has a thickness of 7 μm to 30 μm.