New Sn-Cu/C composite anode materials with high cyclic stability for Lithium ion battery

Sn-Cu/C anode material with core-shell structure was obtained, in which the crystallization of Sn-Cu alloy was weakened. The results show that the weakening of the crystallization decreases the binding force on the interstitial sites and is benefit for the inserting and escaping of the lithium ions. And "Core-shell" structure design can effectively disperse the Sn-Cu alloy particles and leave room for the volume expansion of Sn-Cu alloy. Furthermore, the volume change is controlled within the "core-shell" structure. Through these methods, Sn-Cu/C composite anode material with high cyclic stability was obtained, whose reversible capacity was 450 mAh g^-1, without any capacity loss till the 200^th cycle. The volume change and irreversible capacity loss of Sn-based anode materials can be partly solved by the weakening of the crystallization and "core-shell" structure design. (paper)