Preparation of ZnNbO anode material for high-performance lithium/sodium-ion batteries.

Niobium-based oxides (M-Nb-O) as promising lithium/sodium-ion storage anode materials have attracted much attention. More types of niobium-based oxides are prepared in order to provide more candidates for anode materials. Herein, ZnNbO as a novel intercalation-type anode material has been reported for the first time. Arborescent ZnNbO particles (ZnNbO-A) and stump-like ZnNbO particles (ZnNbO-B) have been prepared by solid-state and solvothermal methods, respectively. Benefiting from the microsized stump-like structure and the exposure of the (110) facet, ZnNbO-B delivers superior long-term cycling stability with a 139.6% capacity retention (291.8 mA h g) over 650 cycles at 0.5 A g and a large reversible specific capacity of 91.4 mA h g at 4.0 A g in lithium-ion batteries. Furthermore, the ZnNbO-B electrode exhibits outstanding cycling stability (100.1 mA h g with 94.5% capacity retention after 400 cycles at 0.5 A g) in sodium-ion batteries. The excellent electrochemical performance of the stump-like ZnNbO-B materials can be attributed to the exposure of the (110) facet, enlarged interlayer spacing, small charge transfer resistance, and high pseudocapacitive contribution. Therefore, ZnNbO-B has great application prospects as an anode material for lithium/sodium-ion storage.