Water-in-Salt electrolyte enabled LiMn2O4/TiS2 Lithium-ion batteries

High electrochemical reversibility of the TiS2 anode in Water-in-Salt electrolyte (21 m LiTFSI in H2O) is demonstrated for the first time. The wide electrochemical window and low chemical activity of H2O in the Water-in-Salt electrolyte not only significantly enhanced the electrochemical reversibility of TiS2 but also effectively suppressed the hydrolysis side reaction in the aqueous electrolyte. Paired with a LiMn2O4 cathode, the LiMn2O4/TiS2 full cell delivers a relatively high discharge voltage of 1.7 V and an energy density of 78 Wh kg(-1) as well as a satisfactory rate performance.