新型氧杂噻唑烷类添加剂在碳酸丙烯酯基电解液成膜机理研究OA

In order to solve the incompatibility between propylene carbonate(PC)-based electrolyte and graphite anode,a new oxathiazolidine-based additive,tert-butyl 1,2,3-oxathiazolidine-3-carboxylate 2,2-dioxide(BOCD),is proposed in this study.With the density functional theory calculations,electrochemical tests,and multi-scale characterizations,the film-forming mechanism at the graphite-electrolyte interface is intensively investigated.The results show that BOCD is more prone to reductive activation than PC.Under Li+coordination and electron injection,its C-O bond preferentially cleaves,leading to the decomposition and formation of a solid electrolyte interphase rich in lithium sulfate,lithium sulfite,and nitrogen-containing organic components,which effectively suppresses solvent co-intercalation and protects the graphite structure.The 1 A·h 3.40 mA·h/cm² graphite||2.769 mA·h/cm² LiNi0.8Mn0.1Co0.1O2 pouch cell using the electrolyte containing BOCD demonstrates stable cycling for 226 cycles,validating the effectiveness of this film-forming strategy in improving the stability of the PC/graphite interface.This work provides a new molecular design strategy and experimental basis for developing PC-based lithium-ion battery electrolytes for wide-temperature and high-reliability applications,including aerospace scenarios.