电沉积法制备Sn-Co-C锂离子电池负极材料

Sn-Co-C Negative Electrode Material for Li-ion Batteries Prepared by Electrodeposition

本文分别采用柠檬酸和EDTA作为络合剂在COCl_2,SnCl_4溶液中用电沉积方法制备Sn-Co合金电极,然后在相同条件下在镀液中加入硬碳制备Sn-Co-C复合电极。充放电测试结果显示EDTA作为络合剂时镀层循环性能明显好于柠檬酸,且比容量也较高。Sn-Co合金电极循环30次比容量保持率达91.6%,加入硬碳的Sn-Co-C复合电极比容量及循环性能较之Sn-Co合金电极都有了较大提高。电子探针结果表明EDTA作为络合剂的Sn-Co-C镀层中Sn、Co、C原子比例分别为61.8401%,22.3788%,12.5409%。SEM观察Sn-Co-C镀层表面为稳定的球状结构。

By adding citric acid and EDTA into CoCl2, SnCl4 solution respectively, Sn-Co alloy electrodes were prepared by electrodeposition, and under the same condition, Sn-Co-C electrodes were prepared by mixing carbon with the solution as above. Charge-discharge tests demonstrate that electrodes prepared by EDTA show much better cyclic capability and higher specific capacity. For Sn-Co alloy electrode, the Charge capacity remains 91.7% of that of the first cycle at the 35th cycle, and by adding C into Sn-Co alloy, both the charge capacity and cyclic capability have large improvement. EPMA results show that the atomic percentages ofSn、Co、C in Sn-Co-C electrode prepared by EDTA are 61.8401%, 22.3788%, 12.5409% respectively. SEM images show that Sn-Co-C deposits are homogeneous spheres.