| abstract |
An additive for lithium secondary battery that enables improvement with respect to the battery capacity, initial efficiency, etc. of lithium secondary battery. A fullerene derivative having a group whose formula weight is 6 or greater is used as the additive for lithium secondary battery. The fullerene derivative having a group whose formula weight is 6 or greater is incorporated in a negative electrode material for lithium secondary battery, a negative electrode for lithium secondary battery and a lithium secondary battery including the negative electrode containing the negative electrode material. The group whose formula weight is 6 or greater of the fullerene derivative is preferably a member selected from the group consisting of alkali metal atoms, chalcogen atoms, halogen atoms, aliphatic hydrocarbon groups, aromatic hydrocarbon groups, heterocyclic groups, oxygen-containing specified groups, sulfur-containing specified groups and nitrogen-containing specified groups. |