Hierarchical novel NiCo₂O₄/BiVO₄ hybrid heterostructure as an advanced anode material for rechargeable lithium ion battery

Hybrid metal oxide heterostructures have been considered as ideal and potential anode materials for lithium ion batteries (LIBs) due to their better electrochemical performances, such as reversible capacity, structural stability and electronic conductivity. Herein, we have demonstrated synthesis of NiCo₂O₄/BiVO₄ heterostructures by simple hydrothermal strategy to construct hybrid xNiCo₂O₄/(1–x)BiVO₄ heterostructures with four selected compositions, that is, x = 10%, 20%, 30% and 40%. XRD shows the phases of NiCo₂O₄ and BiVO₄ and FE-SEM data revealed strong interface coupling between NiCo₂O₄ nanowires and BiVO₄ dendrites. Upon testing for electrochemical properties, the optimized composition of 30%NiCo₂O₄-70% BiVO₄ showed higher reversible capacity of 408.6 mAh/g at a constant current rate of 0.5 A/g after 1000 cycles with columbic efficiency around 99% suggesting potential electrode material for high-performance LIBs. The higher capacity is mainly attributed to the large surface area which can provide more channels and locations for fast Li ion intercalation/de-intercalation into electrode materials. Additionally, improved Li ion storage capacity with superior rate capability of BN-30 electrode could be attributed to its lower charge-transfer resistance. The dendritic and nanowire heterostructure novel system with good stable capacity for LIBs is hitherto unattempted.