Hierarchical 1 T-MoS2/MoOx@NC microspheres as advanced anode materials for potassium/sodium-ion batteries

Metallic MoS2 (1 T-MoS2) is expected as a new anode to effectively storage K+/Na+ due to the merits of high capacity, large layer distance and good metallic conductivity. The main bottleneck of 1 T-MoS2 anode stems from the structure pulverization caused by the large volume changes upon cycling, leading to the rapid capacity fading. Herein, hierarchical N-doped carbon modified 1 T-MoS2/MoOx microspheres (1 T-MoS2/MoOx@NC) assembled by some primary nanoparticles are first fabricated by a facile solvothermal synthesis and followed annealing treatment. As anode materials for potassium-ion batteries, 1 T-MoS2/MoOx@NC delivers the outstanding rate capability (257.9/128.8 mAh g−1 at 0.05/0.5 A g−1) and exceptional long-term cycle life up to 400 cycles. 1 T-MoS2/MoOx@NC as anode materials for sodium-ion batteries also shows high reversible capacity and outstanding cyclic stability (473.8 mAh g−1 over 1300 cycles at 2 A g−1). The related kinetics tests have been used to explain the excellent potassium/sodium storage performances. Meanwhile, the 1 T-MoS2/MoOx@NC//Na3V2(PO4)3 full cell for SIBs has been assembled, which exhibits good electrochemical performances. The discharge capacity can keep at 163.5 mAh g−1 after 300 cycles at 0.5 A g−1. The excellent potassium/sodium storage performances are mainly attributed to the particular hierarchical structure as well as the synergistic effect of 1 T-MoS2, MoOx and N-doped carbon.