Thermal reactions of LiPF6 with added LiBOB - Electrolyte stabilization and generation of LiF4OP

The effect of thermal storage on 1.0 M LiPF6 in 1: 1: 1 ethylene carbonate/ dimethyl carbonate/ diethyl carbonate with 5 wt % added lithium bisoxalatoborate [LiB(C2O4)(2) LiBOB] was investigated. Thermal storage of LiPF6 initiates disproportionation reactions of LiBOB, which generate LiBF4, lithium difluorooxalatoborate [LiBF2(C2O4), LiF2OB], and lithium tetrafluorooxolatophosphate [LiPF4(C2O4), LiF4OP]. The synthesis and characterization of LiF4OP are presented along with a preliminary electrochemical investigation of LiF4OP-based electrolytes.