Thermally stable lithium salts for polymer electrolytes

Abstract Chemical and electrochemical characterization of two new Li salts which exhibit high conductivity in both liquid and polymer solvent systems are presented. When dissolved in non-aqueous solvents such as tetrahydrofuran LiN(SO 2 CF 3 ) 2 , Li bis-(trifluoromethanesulfonyl)imide and LiC(SO 2 CF 3 ) 3 , Li tris-(trifluoromethanesulfonyl)methide are the two most highly conductive organic anion-based Li salts known. Cyclic voltammetry studies show both salts to be electrochemically stable beyond 4 V vs Li. They are also stable indefinitely at elevated temperatures, eg 100°C, unlike the large class of inorganic Li salts based on perhalogenated transition metal and main group ions.