| 摘要 |
PROBLEM TO BE SOLVED: To improve adhesive strength of mutual carbon materials and the carbon material and a current collecting body in a negative electrode, and remarkably improve a highly efficient discharge characteristic and a cycle characteristic by using hydrogenated carboxy modified rubber as a binding agent to bind a negative electrode active material composed of a powdery carbon material to store/release a lithium ion. SOLUTION: A hydrogenation rate of carboxy modified rubber is 30 to 90%, and it is carboxy modified butadiene rubber containing butadiene, and a copolymer of one or more kinds selected from a group composed of ethylene, isoprene and styrene and butadiene is used as a basic skeleton, and the copolymer is carboxilically modified. The carboxy modified butadiene rubber is desirable to be carboxilically modified by using a copolymer of acrylonitrile and butadiene as a basic skeleton. It is ideal to set the butadiene content of this binding agent not less than 20 wt.% and the gel content not less than 60%. |
