ANODE FOR LITHIUM ION SECONDARY BATTERY, LITHIUM ION SECONDARY BATTERY, ELECTRIC POWER TOOL, ELECTRICAL VEHICLE, AND ELECTRIC POWER STORAGE SYSTEM

摘要

There is provided an anode for a lithium ion secondary battery capable of improving the cycle characteristics, a lithium ion secondary battery using the same, an electric power tool using the lithium ion secondary battery, an electrical vehicle using the lithium ion secondary battery, and an electric power storage system using the lithium ion secondary battery. The anode for a lithium ion secondary battery includes an anode active material layer in which a first layer and a second layer respectively containing silicon and a metal element as an anode active material are alternately layered on an anode current collector, and 1.02≦̸A/B≦̸50 is satisfied. A represents a silicon content ratio in the anode active material in the first layer, and B represents a silicon content ratio in the anode active material in the second layer.