Reproduction method for negative electrode active material

Abstract

The present disclosure relates to a reproduction method for obtaining a negative electrode active material with improved rapid charge-discharge property, from a used lithium ion secondary battery. A technology disclosed herein is directed to a reproduction method for a negative electrode active material from a used lithium ion secondary battery, including: a preparation step of preparing the used lithium ion secondary battery including a positive electrode, a negative electrode including a negative electrode active material containing a carbon material, and an electrolyte; a charging step of charging the lithium ion secondary battery; a discharging step of discharging the lithium ion secondary battery obtained after the charging step, at a discharge rate higher than a charge rate of the charging step; and a recovery step of recovering the negative electrode active material containing the carbon material from the negative electrode in the lithium ion secondary battery obtained after the discharging step.

Dependencies are inferred from the claim text.