Vanadium Molybdenum Disulfide Nanosheets Anchoring on Carbon Cloth as High-Energy Density Cathode for Magnesium-Lithium Hybrid Batteries.

Abstract

Magnesium-lithium-ion hybrid batteries (MLIBs) have gained significant attention since the combination of a dendrite-free and low-cost magnesium anode with lithium-ion storage cathodes. However, the lack of high-performance cathodes has severely hindered their development, limited by the lower operating voltages of electrolytes. Herein, vanadium molybdenum disulfide nanosheets anchoring on flexible carbon cloth (VMS@CC) are constructed as high-performance cathodes for MLIBs, which inherit the electrochemical properties of high-voltage VS2 and high-capacity MoS2, simultaneously. By adjusting the V and Mo atomic ratio, the VMS@CC cathode for MLIBs delivers a record maximum energy density of 275.5 Wh kg-1 with a high working voltage of 1.07 V at 50 mA g-1. Meanwhile, under the synergistic effects of the conductive carbon cloth matrix, abundant hetero-interfaces and defects, as well as expanded interlayer spacing, the VMS@CC cathode displays superior rate capability and long-term cycling stability. Ex situ analyses demonstrate the VMS nanosheets cathode exhibits a Li+/Mg2+ co-insertion/extraction mechanism in MLIBs, following the in situ insertion of organic species in the hybrid electrolyte during the aging process. The fabricated flexible cathode herein provides a new insight into the construction of high-energy density cathodes for MLIBs.