Anchoring hollow MoO₂ spheres on graphene for superior lithium storage

Hollow MoO₂ spheres anchored on nitrogen-doped graphene (H-MoO₂@rGO) are synthesized with an in situ self-assembly approach. The hollow structure could provide sufficient space to accommodate the volume variation of MoO₂ during the discharge-charge process, thus improving the cycling stability. Nitrogen-doped graphene can accelerate the charge transfer. Moreover, the graphene and MoO₂ are proved to be strongly connected through C–O–Mo linkage, which provide good pathways for charge transfer and thus allowing an improved rate capability. Benefiting from the above features, H-MoO₂@rGO delivers impressive cycling stability with a capacity of 414 mAh g⁻¹ after 1000 cycles at 2 C. Even at a high discharge/charge rate of 5 C, the composite still could deliver a capacity of 478 mAh g⁻¹.