Nonflammable Electrolytes for Lithium-Ion Batteries Containing Dimethyl Methylphosphonate

A novel nonflammable electrolyte for lithium-ion batteries has been developed. The optimized electrolyte is composed of LiPF6 in a mixture of carbonate solvents with added dimethyl methylphosphonate as a flame retarding cosolvent and lithium bis(oxalatoborate) as an anode film forming additive. Conductivity, thermal stability, electrochemical stability, self extinguishing times, electrochemical cycling, and ex situ surface analysis of the cycled electrodes are reported. This novel electrolyte has a comparable cycling efficiency to the current state-of-the-art electrolytes for lithium-ion batteries but is nonflammable. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3473828] All rights reserved.