VS4/MoS2 cathodes with long cycle life and high rate performance for hybrid magnesium-lithium batteries

Hybrid magnesium-lithium batteries (MLIBs) have become the focus of research due to the advantages of combining a magnesium metal anode (free dendrite) and Li-driven reaction cathode (fast ion diffusion rate). VS4 with large interchain space can be used as a potential cathode for MLIBs, but its low conductivity and weak structural stability limit the development of MLIBs. In this work, MoS2 was introduced into VS4 to induce the generation of abundant sulfur vacancies, which improved the structural stability and Li+ ion transport properties of VS4. The VS4/MoS2 cathode retains stability and an impressively high reversible capacity of 581.7 mAh·g−1 after 100 cycles, corresponding to a capacity retention of 98.99 % (compared with the second cycle). Meanwhile VS4/MoS2 still has 472.64 mAh·g−1 at high current density of 1500 mA·g−1, which is much higher than that of NF-VS4 (11.9 mAh·g−1) and VF-VS4 (29.8 mAh·g−1). This work points the way to ameliorate Mg-based rechargeable batteries.