NEGATIVE ELECTRODE MATERIAL FOR LITHIUM ION BATTERIES

摘要

A negative electrode material is provided for lithium ion batteries offering a high capacity and a long cycle life. It is an alloy material consisting essentially of Si, Al, M1, and M2 wherein M1 is a transition metal, and M2 is a metal element of Groups 4 and 5, and having an Si-Al-M1-M2 alloy phase constituting fine crystal grains and an Si phase precipitating along crystal grain boundaries to form a network.