Thermal Behavior of LixCoO2 Cathode and Disruption ofSolid Electrolyte Interphase Film

Bulletin of the Korean chemical society

Jung Hun Lee¹  Hyun Soo Kim¹  Younggi Hwang¹  Bong Soo Jin¹  Duck Jun Lee¹  Chil Hoon Doh¹  Seong In Moon¹  Angathevar Veluchamy¹  Dong Hun Kim¹ 

关键词: Cathode;    LixCoO2;    Thermal analysis;    Thermal stability;    Solid electrolyte film;   

DOI  :  

学科分类：化学（综合）

来源: Korean Chemical Society

【 摘 要 】

Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and ion chromatography(IC) were employed to analyze the thermal behavior of Li_xCoO₂ cathode material of lithium ion battery. The mass loss peaks appearing between 60 and 125�? in TGA and the exothermic peaks with 4.9 and 7.0 J/g in DSC around 75 and 85 oC for the Li_xCoO₂ cathodes of 4.20 and 4.35 V cells are explained based on disruption of solid electrolyte interphase (SEI) film. Low temperature induced HF formation through weak interaction between organic electrolyte and LiF is supposed to cause carbonate film disruption reaction, Li₂CO₃ + 2HF �? 2LiF + CO₂ + H₂O. The different spectral DSC/TGA pattern for the cathode of 4.5 V cell has also been explained. Presence of ionic carbonate in the cathode has been identified by ion chromatography and LiF reported by early researchers has been used for explaining the film SEI disruption process. The absence of mass loss peak for the cathode washed with dimethyl carbonate (DMC) implies ionic nature of the film. The thermal behavior above 150 oC has also been analyzed and presented.

【 授权许可】

Unknown