Fluorinated organic solvents in electrolytes for lithium ion cells

A novel partly fluorinated solvent for lithium ion batteries, N,N-dimethyl trifluoracetamide (DTA), is presented. The physical properties and the electrochemical behaviour of this compound are investigated. With its low viscosity and high boiling point and flash point it could replace low viscosity solvents (thinners) such as dimethyl carbonate or diethyl carbonate currently used in lithium ion battery electrolytes to achieve the demand for safer lithium ion batteries. The outstanding filming properties allow to use the DTA even in mixtures with PC in amounts of 10%. With both solvents having a freezing point below −40°C, the mixture is promising as low temperature electrolyte.