Negative electrode for lithium ion secondary battery and lithium ion secondary battery

1. A negative electrode for a lithium ion secondary battery, comprising:

a negative electrode current collector; and

a negative electrode active material for a lithium ion secondary battery, which is disposed on the negative electrode current collector and contains a carbon material, an aqueous binder, and a conductive agent,

wherein the carbon material is a graphite particle having a covering layer containing amorphous carbon by 5 wt % or less relative to a total weight of the carbon material;

wherein the negative electrode active material has from 4 wt % to 7 wt % of the aqueous binder relative to the total weight of the negative electrode active material;

wherein the only carbon particle in the carbon material is the graphite particle;

wherein hydroxyl groups are conjugated to a surface of the graphite particle, and

wherein the graphite particle has an uneven and irregular surface.

2. The negative electrode for a lithium ion secondary battery according to claim 1 , wherein a weight change rate of the carbon material, which is obtained by thermogravimetry in an atmosphere containing water vapor, is 5 wt % or less.

3. The negative electrode for a lithium ion secondary battery according to claim 1 , wherein the aqueous binder comprises at least one material selected from styrene butadiene rubber, carboxymethyl cellulose, and a mixture thereof.

4. The negative electrode for a lithium ion secondary battery according to claim 1 , wherein the graphite comprises natural graphite.

5. The negative electrode for a lithium ion secondary battery according to claim 1 , wherein a weight change rate of the carbon material is 5 wt % or less, in which the weight change rate of the carbon material is obtained by thermogravimetry in a nitrogen atmosphere with a water vapor partial pressure of 50 kPa by increasing a temperature up to 800° C. at a temperature increasing speed of 30° C./min and then increasing up to 1200° C. at a temperature increasing speed of 5° C./min.

6. The negative electrode for a lithium ion secondary battery according to claim 1 , wherein the aqueous binder comprises at least one material selected from a group consisting of butadiene rubber (BR), chloroprene rubber (CR), isoprene rubber (IR), and acrylonitrile butadiene rubber (NBR).

7. The negative electrode for a lithium ion secondary battery according to claim 1 , wherein the aqueous binder comprises polyvinylidene fluoride (PVDF).

8. The negative electrode for a lithium ion secondary battery according to claim 1 , wherein the aqueous binder comprises at least one material selected from a group consisting of xanthan gum, guar gum, and pectin.

9. The negative electrode for a lithium ion secondary battery according to claim 1 , wherein the aqueous binder comprises polytetrafluoroethylene (PTFE) and/or polyvinyl fluoride (PVF).

10. The negative electrode for a lithium ion secondary battery according to claim 1 , wherein the aqueous binder comprises at least one conductive polymer selected from the group consisting of polyanilines, polythiophenes, polyacetylenes, and polypyrroles.

11. The negative electrode for a lithium ion secondary battery according to claim 1 , further comprising at least one conductive agent selected from the group consisting of carbon fiber, carbon black, activated carbon, mesoporous carbon, fullerenes, and carbon nanotube.

12. The negative electrode for a lithium ion secondary battery according to claim 1 , further comprising at least one additive selected from the group consisting of thickener, dispersant, and stabilizer.

13. The negative electrode for a lithium ion secondary battery according to claim 1 , wherein the graphite particle does not touch an adjacent graphite particle.

14. The negative electrode for a lithium ion secondary battery according to claim 1 , wherein the carbon material consists of the graphite particle.

15. A lithium ion secondary battery comprising a power generating element inside a package, the power generating element comprising:

a positive electrode containing a positive electrode active material layer disposed on a positive electrode current collector;

a negative electrode containing a negative electrode active material layer disposed on a negative electrode current collector;

a separator; and

an electrolyte solution, wherein the negative electrode is the negative electrode according to claim 1 .

16. A negative electrode for a lithium ion secondary battery, comprising:

a negative electrode current collector; and

a negative electrode active material for a lithium ion secondary battery, which is disposed on the negative electrode current collector and contains a carbon material, an aqueous binder, and a conductive agent,

wherein the carbon material is a graphite particle having a covering layer containing amorphous carbon by 5 wt % or less relative to a total weight of the carbon material;

wherein the negative electrode active material has from 4 wt % to 7 wt % of the aqueous binder relative to the total weight of the negative electrode active material;

wherein the only carbon particle in the carbon material is the graphite particle; and

wherein the graphite particle is not in contact with an adjacent graphite particle.

17. The negative electrode for a lithium ion secondary battery according to claim 16 , wherein hydroxyl groups are conjugated to a surface of the graphite particle.

18. The negative electrode for a lithium ion secondary battery according to claim 16 , wherein the graphite particle has uneven and irregular surface.

19. The negative electrode for a lithium ion secondary battery according to claim 16 , wherein the carbon material consists of the graphite particle.