锡基复合电极的电化学性能研究

Study on electrochemical properties of tin-based composite electrode

化学还原法制备的Sn-SnSb复合材料具有良好的电化学性能,其中SnSb百分数为24 5%的材料性能更优越,循环30次后容量还能保持在380m·Ah/g左右;热处理能有效地提高复合电极的循环性能,含SnSb百分数为24 5%的材料循环性能提高显著,循环50次后容量可维持在400m·Ah/g左右.运用循环伏安实验验证了Li与Sn、Sb的多步合金化步骤,阻抗分析表明,在嵌脱锂的不同电位阶段电极阻抗变化呈一定趋势,电位越低,阻抗越大.

Sn-SnSb composite materials prepared by chemical reduction showed excellent electrochemical properties. Composite materials, which contain 24.5wt% SnSb, displayed better properties than other materials and delivered capacity of 380mAh/g after 30 cycles. Electrochemical performance of composite electrode can be improved by heat treatment. Capacity of 400mAh/g can be discharged by composite materials which contain 24.5wt% SnSb and were annealed at 300°C. Moreover, multistep reactions of lithium with Sn and Sb were proved by cyclic voltammetry. Electrochemical impedance spectroscopy (EIS) showed that the increase of electrode impedance with the reduction of potential in the first cycle.