Bubble-sheet-like Ni0.85Co2.15V2O8 nanosheets for high-rate lithium storage

Abstract Transition-metal vanadates (TMVs) are widely acknowledged as promising anode candidates for lithium-ion batteries (LIBs). Nevertheless, it is a great challenge to synthesize TMVs with complex nanostructures and multinary compositions. In this work, quaternary Ni0.85Co2.15V2O8 with a bubble-sheet-like morphology is facilely synthesized by a self-template method. Moreover, the novel synthesis strategy for Ni0.85Co2.15V2O8 only involves an anion-exchange reaction and a subsequent topotactic conversion. Owing to the porous nano-architecture and the synergistic effect of multinary compositions, the as-prepared Ni0.85Co2.15V2O8 porous nanosheet (PNS) anode exhibits remarkable electrochemical properties with a high specific capacity up to 1633 mA h g-1 at 0.2 A g-1, superior rate capability (583 mA h g-1 at 10 A g-1) and excellent cyclic stability (627 mA h g-1 after 2000 cycles at 5 A g-1). Such outstanding electrochemical properties make Ni0.85Co2.15V2O8 PNS a promising high-rate anode for LIBs. This strategy of designing bubble-sheet-like architecture can also be applied to other multinary TMVs.