NaBF_4对锂离子电池石墨负极性能的影响

Influence of NaBF_4 on the Graphite Anode for Li-Ion Battery

利用恒流充放电、循环伏安、交流阻抗、SEM、EDS等测试技术研究了在锂离子电池石墨负极和浆过程中加入NaBF4对其电化学性能的影响。结果表明:NaBF4的最佳添加量为2%,可明显提高石墨电极的首次放电比容量和充放电效率;电极的自放电性能和循环稳定性得到明显改善。室温条件下,添加了2%NaBF4的电极以放电容量计算的自放电率为0.87%.d-1,比未添加时降低了15%;循环伏安、EDS以及SEM测试结果表明,四氟硼酸钠参与了石墨电极的成膜过程,改变了SEI膜的组分和形貌。

The influence of NaBF4 on graphite anode for Li-ion battery was studied by adding it into the process of slurry preparation with the methods of galvanostatic charge-discharge, CV, EIS, SEM and EDS. The results showed that： when the amount of NaBF4 was 2%, not only the reversible capacity at the initial cycle was improved, but also the efficiency. The performances of self-discharge and the cycle stability were all both improved. And its self-discharge rate calculated by capacity was 0.87%·d^-1, reduced15% than it without NaBF4. The results of CV, EDS and SEM tests both suggested that, NaBF4 involved in the process of SEI formation, changing its components and morphology.