The thermal decomposition of LiPF6 in the solid state and as solutions in dialkyl carbonates has been investigated. The thermal decomposition of LiPF6 was investigated with differential scanning calorimatry (DSC) suggesting decomposition to LiF and PF5. In solution, PF5 reacts with dialkylcarbonates to form a variety of decomposition products including carbon dioxide (CO2), ethers (R2O), alkylfluorides (RF), phosphorus oxyfluoride (OPF3) and fluorophosphates (OPF2OR, 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). (C) 2003 Elsevier Science B.V. All rights reserved.