Magnesium Ion Embedded and Graphene Modified Vanadium Pentoxide Cathode for Superior Magnesium Storage Performance

The strong interaction between Mg2+ and vanadium pentoxideVanadium pentoxide deteriorates crystal stability, which restricts the highly efficient magnesiumMagnesium storage of vanadium pentoxide. In contrast to the typical strategy of introducing interlayer water, the establishment of a fast diffusion path and robust structure are crucial for enhancing the magnesium storage properties of vanadium pentoxideVanadium pentoxide. Herein, we synthesize a new Mg2+ host of MgxV2O5@GO with Mg2+ pre-intercalationPre-intercalation and graphene modification through a simple hydrothermal method. In MgxV2O5@GO, Mg2+ acts as a ‘pillar’ within the layered V2O5 to alleviate the crystal structure from collapse, while graphene serves as a conductive network to optimize the charge transfer efficiency. Remarkably, MgxV2O5@GO cathodeCathode achieves an outstanding cycling life of 5000 cycles at 1 A g−1 with an excellent capacity retention of 98.3%. Profited from the conductive graphene that offers a rapid charge transfer network, MgxV2O5@GO exhibits a considerable rate performance of 150.6/81.7 mAh g−1 at 0.02/3 A g−1.