Positive electrode for lithium ion secondary battery, and lithium ion secondary battery using the same

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

a positive electrode current collector;

a conductive layer which is disposed directly or indirectly on the positive electrode current collector, and which comprises a conductive particle, a polymer particle, and a resin comprising a structural unit derived from a nitrile group-containing monomer; and

a positive electrode active material layer disposed directly or indirectly on the conductive layer,

wherein the resin comprising a structural unit derived from a nitrile group-containing monomer comprises at least one selected from the group consisting of a structural unit derived from a monomer represented by the following Formula (I) and a structural unit derived from a monomer represented by the following Formula (II):

wherein, R 1 represents H or CH 3 , R 2 represents H or a monovalent hydrocarbon group, and n represents an integer from 1 to 50; and

wherein, R 3 represents H or CH 3 , and R 4 represents an alkyl group having from 4 to 100 carbon atoms.

2. The positive electrode for a lithium ion secondary battery according to claim 1 , wherein a mass ratio of a total of the conductive particle and the polymer particle with respect to the resin comprising a structural unit derived from a nitrile group-containing monomer (total of the conductive particle and the polymer particle: the resin) included in the conductive layer is from 99.9:0.1 to 95:5.

3. The positive electrode for a lithium ion secondary battery according to claim 2 , wherein a thickness of the conductive layer is from 1 μm to 10 μm.

4. The positive electrode for a lithium ion secondary battery according to claim 2 , wherein an average particle size of the polymer particle is from 0.05 μm to 5 μm.

5. The positive electrode for a lithium ion secondary battery according to claim 2 , wherein the conductive particle is a carbon particle.

6. The positive electrode for a lithium ion secondary battery according to claim 2 , wherein an average particle size of a primary particle of the carbon particle is from 10 nm to 500 nm.

7. The positive electrode for a lithium ion secondary battery according to claim 2 , wherein the polymer particle is a polyolefin particle.

8. The positive electrode for a lithium ion secondary battery according to claim 2 , wherein a mass ratio of the conductive particle with respect to the polymer particle (conductive particle: polymer particle) is from 2:98 to 20:80.

9. The positive electrode for a lithium ion secondary battery according to claim 2 , wherein the positive electrode active material layer comprises a lithium-containing composite metal oxide as a positive electrode active material.

10. The positive electrode for a lithium ion secondary battery according to claim 2 , wherein a packing density of the positive electrode active material layer is from 2.2 g/cm 3 to 2.8 g/cm 3 .

11. A lithium ion secondary battery, comprising the positive electrode for a lithium ion secondary battery according to claim 2 .

12. The positive electrode for a lithium ion secondary battery according to claim 2 , wherein the conductive layer is an aggregate of a mixture comprising conductive particles, polymer particles, and the resin comprising a structural unit derived from a nitrile group-containing monomer.

13. The positive electrode for a lithium ion secondary battery according to claim 12 , wherein an average particle size of the polymer particles is from 0.05 μm to 5 μm.

14. The positive electrode for a lithium ion secondary battery according to claim 12 , wherein an average particle size of the polymer particles is from 0.2 μm to 2 μm.

15. The positive electrode for a lithium ion secondary battery according to claim 12 , wherein a mass ratio of the conductive particles with respect to the polymer particles (conductive particles: polymer particles) is from 2:98 to 20:80.