| 摘要 |
PROBLEM TO BE SOLVED: To provide a long-life lithium ion battery.SOLUTION: A composite negative electrode material for lithium ion batteries comprises: a negative electrode active material consisting of Si, SiOx, or a silicon alloy; and a coating layer which covers the surface of the negative electrode active material. In the negative electrode material, the coating layer includes a polymer having a mesh-like structure, and accounts for 1-20% by mass. The coating layer is formed by covering the surface of the active material with the polymer having a mesh-like structure which results from crosslink and therefore, the coating layer has ion conductivity as well as electron conductivity. Thus, it is possible to ensure that lithium ions can be smoothly fit into and released from negative electrode active material particles. In addition, the invention has the advantage that the coating layer has a mesh-like structure, and the mesh-like structure has a good mechanical strength per se. |
