Hierarchical novel <scp> NiCo ₂ O ₄ </scp> / <scp> BiVO ₄ </scp> hybrid heterostructure as an advanced anode material for rechargeable lithium ion battery

Abstract

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.