A novel family of salts suitable for lithium battery application was synthesized and characterized. These salts have a large delocalized anion whose charge is spread over a single SO2 and a phenyl ring. Remarkable properties were obtained for the lithium N-(3-trifluoromethyl phenyl) trifluoromethanesulfonamide salt or LiTFPTS. The electrochemical stability window is around 4.0 V and its conductivity in solid poly(ethylene oxide) or PEO is close to the one of the lithium perchlorate salt. Calorimetric analysis also showed that LiTFPTS behaves as a plasticizer since it hinders, to a certain extent, the PEO crystallization when it is used in a solid polymer matrix. Above all, its synthesis is quite straightforward and leads to potentially inexpensive salts as the starting amines are made commercially on a large scale.