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

•“Water-in-Salt” electrolyte featured with wide electrochemical window.•TiS2 can be used as an anode in aqueous Li-ion battery for the first time.•LiMn2O4/TiS2 full cell delivers a high energy density of 78 Wh kg− 1.

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.

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