硅钛负极储锂过程交流阻抗分析

Study on Electrochemical Impedance Spectroscopy of Silicon-Titanium Anode in Lithiation Storage Process

为研究钛含量对硅钛负极电化学储锂反应动力学过程的影响,通过交流阻抗分析法测试了硅钛摩尔比分别为50和25时,硅钛负极在200mA/g电流密度下充放电100圈后的电阻值。结果表明,降低硅在复合材料中的含量有利于减少SEI(Solid Electrolyte Interphase,固体电解质膜)的生成量、降低电荷转移电阻值。当硅钛摩尔比为25时,负极具有更好的电极反应动力学过程,电荷转移阻抗从初始阶段142Ω增加至212Ω。

In order to investigate influence of titanium content on electrochemical lithiation storage kinetics of silicon-titanium anode,resistance value-of anode was measured as it was discharged/charged for 100 cycles at current density of 200 mA/g with Ti/Si molar ratios of 50 and 25 respectively.The results suggest that decreasing silicon concentration of composite benefits-reduces production of SEI(Solid Electrolyte Interphase)and thus reduces charge transfer resistance.As molar ratio of Ti/Si is 25,the anode exhibits better reaction kinetics with charge transfer resistance rising from 142Ωto 212Ω.