Thermal stability of lithium-ion battery electrolytes

Abstract The thermal decomposition of LiPF 6 in the solid state and as solutions in dialkylcarbonates has been investigated. The thermal decomposition of LiPF 6 was investigated with differential scanning calorimatry (DSC) suggesting decomposition to LiF and PF 5 . In solution, PF 5 reacts with dialkylcarbonates to form a variety of decomposition products including carbon dioxide (CO 2 ), ethers (R 2 O), alkylfluorides (RF), phosphorus oxyfluoride (OPF 3 ), and fluorophosphates (OPF 2 OR, OPF(OR) 2 ). The structure of the decomposition products are supported by nuclear magnetic resonance (NMR) spectroscopy and gas chromatography with mass selective detection (GC–MS).