锂离子在LiMn_2O_4正极材料中的界面过程

Studies on the Interfacial Process of Lithium Ion in the Cathode Material of LiMn_2O_4

采用交流阻抗法研究了锂离子在LiMn2O4正极材料中的界面过程.结果表明:LiMn2O4电极的交流阻抗复平面图中高频区的半圆,是由电解液中的锂离子在LiMn2O4表面吸附形成表面层的电阻和电容引起的,中频区的半圆是由电极LiMn2O4内的电荷转移反应电阻和双电层电容引起的,而低频区的直线则是由锂离子在LiMn2O4中的扩散引起的.

The interfacial process of lithium ion in the cathode material of LiMn_2O_4 was investigated through the technique of impedance spectroscopy.The results show that the semicircle in the high frequency range is associated with the resistance and capacitance caused by the absorption of lithium ion of electrolyte onto the surface of LiMn_2O_4.The semicircle in the middle frequency range is caused by the charge-transfer resistance and double-layer capacitance.The inclined line in the low frequency range is caused by the diffusion of lithium ion in LiMn_2O_4.