NEGATIVE ELECTRODE FOR LITHIUM ION SECONDARY BATTERY AND LITHIUM ION SECONDARY BATTERY COMPRISING THE SAME

摘要

A negative electrode for a lithium ion secondary battery and a lithium ion secondary battery containing the negative electrode are provided to improve capacity, high rate charge/discharge characteristics and cycle characteristics. A negative electrode comprises a current collector(2); and an active material layer(1) supported on the current collector, wherein the active material layer comprises a first layer(1a) and a second layer(1b) which are laminated alternatively in the thickness direction of the active material layer. The first layer comprises an active material represented by SiOx, and the second layer contains oxygen in an amount larger than the first layer, wherein 0.1<=x<=0.9. Preferably the thickness of the first or second layer is 5 nm to 1 micrometer; and the thickness of the active material layer is 0.5-30 micrometers.