Carbon-Thermal Synthesis of Sn/C Composites for Secondary Lithium-Ion Batteries

Electrochemical active Sn/C composites were synthesized by carbon-thermal reduction method from SnO ₂ and C in Ar atmosphere at 950 °C. The obtained composites were characterized by XRD and SEM. Lithium insertion/ extraction characteristics of the composites were examined by constant current charge-discharge and cyclic volta.rnrnetry methods(CV). The results show that Sn metal spheres are embedded in excessive flocculent carbon matrix homogeneously. The average size of Sn spheres becomes larger after heating for a longer lime. Sn/C composite heated for 8 h exhibits initial lithium insertion specific capacity of 1 014 mAh·g ^-1 and the highest reversible lithium insertion specific capacity of 406 mAh·g ^-1 after 15 cycles coupled with a reasonable capacity rete:ntion(4%loss/cycle).