Lithium Ion Secondary Battery

Abstract

An object of the present invention is to provide a lithium ion secondary battery having a high power over a wide range of low SOC to high SOC while securing a battery capacity, and having a good storage property (a capacity retention rate). One aspect of the present embodiment includes a lithium ion secondary battery which includes: a positive electrode; and a negative electrode, in which the negative electrode includes a current collector and a negative electrode active material layer disposed on at least one side of the current collector, the negative electrode active material layer includes a negative electrode active material including graphite particles (A) and graphite particles (B) on which amorphous carbon fine particles are supported, and the number of the amorphous carbon fine particles per unit area is 0.4 pieces/μm2 or more in the graphite particles (B) on which the amorphous carbon fine particles are supported.

Dependencies are inferred from the claim text.