正极材料锰酸锂SEI膜研究

Study on SEI film of LiMn_2O_4

利用不同测试方法研究了锰酸锂表面SEI膜的形成条件及其主要构成。研究结果表明:锰酸锂表面SEI膜在第一周循环过程中形成,在第二周循环过程中会经历一个膜的重整过程,其膜厚度为5.08 nm;SEI膜组分是由于电极材料表面所发生的化学反应和电化学反应所产生,其主要构成为氟化锂、碳酸锂和有机锂化合物,有机锂化合物包括CH3OLi、CH3OCO2Li、CH3CH2Li、CH3CH2OLi、(CH2OCO2Li)2、LiCH2CH2OCO2Li、LiOCH2CH2OCO2Li等。

The formation conditions and main components of the solid electrolyte interface （SEI film） on the surface of LiMn2O4 were studied.The results showed that the SEI film was formed in the first cycle, and the SEI film would experience a restructuring process during the second cycle ; and the SEI film＇s thickness was 5.08 nm.The main components of SEI were generated by chemical reaction and electrochemical reaction on the surface of electrode materials.And the main components were LiF, lithium carbonate,and organolithium compounds.Organolithium compounds included CH3OLi,CH3OCOELi,CHaCH：Li, CH3CH2OLi, （CH2OCO2Li）：, LiCHECHEOCOELi, LiOCH2CH2OCO2Li and so on.