Lithium ion secondary battery

Abstract

The present application discloses a lithium ion secondary battery, comprising a positive electrode plate comprising a positive active material layer, a negative electrode plate comprising a negative active material layer, wherein: the positive active material layer comprises a lithium manganese-based positive active material as a positive active material; the negative active material layer and/or electrolyte comprise a sulfur-containing compound so that the sulfur-containing compound forms a sulfur-containing solid electrolyte interface film in the negative active material layer, and the mass percentage v of the sulfur element present in the negative active material layer containing the interface film and the mass percentage u of the manganese element present in the positive active material satisfy the following formula: v=0.018u+ω, in which u and v both are in wt % and ω is 0.01˜2. The present lithium ion secondary battery exhibits higher safety, cycle and storage performances.

Dependencies are inferred from the claim text.