LITHIUM ION SECONDARY BATTERY

摘要

A negative electrode sheet of a lithium-ion secondary battery has a negative electrode current collector and a negative electrode active material layer on the negative electrode current collector. The negative electrode active material layer contains flake graphite particles and has a first region neighboring the negative electrode current collector and a second region neighboring a surface side that are different in perpendicularity of the graphite particles. The perpendicularity of the graphite particles is defined as (m1/m2), where, when the inclination &thetas;n of each of the graphite particles is specified relative to a surface of the negative electrode current collector, m1 is the number of the graphite particles having an inclination &thetas;n of 60°≦̸&thetas;n≦̸90° and m2 is the number of the graphite particles having an inclination &thetas;n of 0°≦̸&thetas;n≦̸30°.