Hybrid ternary co-intercalation in interlayer of vanadium oxide cathode enables high-capacity and stable zinc ion batteries

Abstract

Aqueous rechargeable zinc ion batteries (ARZIBs) are highly suitable for grid-scale energy storage because of high safety, low cost, and environmental friendliness. However, developing high-capacity and stable cathode materials for their wide applications is still a significant challenge. Herein, Nax(NH4)2-xV10O258H2O (NNVO), a novel hybrid ternary co-intercalation vanadium oxide cathode, has been prepared by a facile sequential hydrothermal method. The interlayer space of NNVO can be expanded by H2O, NH4+, and Na+ embedding, promoting the collaborative increase of Zn2+ storage active sites, lattice structure stability, and Zn2+ migration ability. Hence, the NNVO displays a near-theoretical capacity of 481.2 mAh g-1 at 0.1 A g-1 and can still be maintained by about 50% (239.5 mAh g-1) when the current density is increased by 50 times. Meanwhile, the NNVO displays a meagre attenuation rate of 0.02% per cycle during 500 cycles at 0.2 A g-1, indicating high low-current cycle stability. Meanwhile, the assembled pouch battery exhibits a long cycle life of 2000 times and excellent capacity retention of 95% at 2.0 A g-1, displaying valuable practical potential. This work highlights a promising NNVO cathode for high-capacity and highly stable ARZIBs, and provides an available co-intercalation strategy and method to improve capacity and stability for interlayer-adjust cathode materials.