中文摘要：

为探究人造石墨包覆修饰处理对锂离子电池负极固相扩散系数的影响。弄清锂离子在包覆改性石墨中的传输扩散过程。采用交流阻抗测试技术对包覆修饰前后人造石墨中锂离子的扩散系数进行测试。结果表朋，锂离子在人造石墨材料中的传输过程由锂离子从电解液穿过膜层和在材料中的嵌入两步组成。嵌锂过程由固相扩散控制。改性前后样品的扩散系数数量级在10^-12之内，包覆修饰可对样品的固相扩散系数略有提高。

英文摘要：

A C. impedance spectroscopy measurement was applied to analyze Li^＋ diffusion in waste artificial graphite before and after coating modification and the effect of coating modification on Li^＋ diffusion coefficient in it was investigated. The results show that Li^＋ diffusion in artificial graphite working electrode can be divided into two steps, the first is Li^＋ charge--transfer in the film and the diffusion of Li^＋ between AG layers, the other is the controlling steps. Diffusion coefficient is in progression 10-12, and coating modification can enlarge Li^＋ diffusion coefficient.