[中文文摘]用SEM和EIS法研究了LiCoO2材料表面SEI膜的形貌特征及锂离子在其中的扩散动力学行为。SEM结果表明:化成后的LiCoO2材料表面存在SEI膜,其形貌和厚度与溶剂密切相关,在PC溶剂中形成的SEI膜要比DMC溶剂中形成的薄。EIS结果显示:锂离子在SEI膜中的扩散过渡时间比在LiCoO2材料中小1个数量级,但是扩散系数却小3~4个数量级。[英文文摘]The morphological character of the SEI layers formed on the surface of LiCoO2 and the Li ion diffusion kinetics in it were studied by the methods of SEM and EIS.The result of SEM indicated that the SEI layer was found on the surface of LiCoO2 after formation,its morphology and thickness were closely related with the solvent,the SEI layer formed in PC solvent was thinner than that formed in DMC solvent.The result of EIS showed that the Li ion diffusion transition time in SEI film was shorter for 1 order of magnitude than in LiCoO2 material , but its transfer diffusion coefficient was smaller for 3～4 orders of
magnitude。973项目(2002CB211807); 福建省化学电源科技创新平台(2006H0090)
