PVP incorporated MoS2 as a Mg ion host with enhanced capacity and durability†
MoS2 with enlarged interlayer spacing exhibits high Mg-ion storage capacity due to the accelerated kinetics of Mg2+, however, continuous decay of capacity occurs during the charge/discharge process, and the exfoliation of MoS2 monolayers is observed because of the weakened van der Waal's interaction in MoS2 interlayers. In the present study, PVP–MoS2 nanospheres with an interlayer spacing of 0.97 nm are synthesized by a hydrothermal method, and employed as Mg-ion hosts. The characterization of MoS2 interlayers indicates that PVP is incorporated between MoS2 monolayers, and the former interacts with the latter to sustain the layered structure of nanospheres. PVP–MoS2 shows a capacity of 143.4 mA h g−1 at a current density of 20 mA g−1, and retains 92% of the capacity after 100 cycles due to its strong structural stability. This study provides a feasible approach to prepare MoS2 hosts with enhanced capacity and durability.