Study of Co-Sn and Ni-Sn alloys prepared in molten chlorides and used as negative electrode in rechargeable lithium battery

摘要

Ni_3Sn_2 and several Co-Sn alloys prepared by electrodeposition in molten LiCl-KCl were studied as anode materials in rechargeable Li-ion battery. In the case of Ni_3Sn_2, the charge-discharge curves do not exhibit any plateau in contrast with Co-Sn alloys. For Ni_3Sn_2, the reversible capacity and the coulombic efficiency tend to constant values of about 225 mAh/g and 85%, respectively, after subsequent cycles. Among the studied Co-Sn alloys, the best electrochemical performances was observed when CoSn_2 was used as anode material: the reversible capacity and the coulombic efficiency observed after 60 cycles were about 530 mAh/g and 96%, respectively. Whatever the alloys, SEM investigations performed before and after cycling do not reveal any significant difference between the original material and the cycled material, indicating a good stability of the electrodeposited films upon cycling.