[1] Peking Univ, Coll Engn, Dept Mat Sci & Engn, Beijing 100871, Peoples R China
[2] Beijing Inst Technol, Sch Mat Sci & Engn, Beijing 100081, Peoples R China
[3] Collaborat Innovat Ctr Elect Vehicles Beijing, Beijing 100081, Peoples R China
[4] Peking Univ, Coll Engn, BIC ESAT, Beijing 100871, Peoples R China