Dual-vapour-thermal engineering evoking bound water pathways of vanadium oxide for high-rate and durable zinc-ion storage
Ting He, Jiugang Hu, Yuqing Luo, Pengfei Zhu, Shan Cai, Yi Wang, Hongshuai Hou, Guoqiang Zou, Xiaobo Ji
Abstract
Vanadium oxides have attracted extensive attention as promising cathode materials for aqueous zinc-ion batteries (AZIBs) owing to their variable valences and laminar structures. However, the strong interaction between divalent Zn 2+ and the [VO n ] host lattice limits its application. In this study, a facile dual-vapour-thermal engineering strategy was proposed for the first time to reconstruct V 2 O 5 as an advanced cathode for AZIBs . Synchrotron radiation X-ray adsorption and photoelectron spectroscopies revealed that the high pressure and thermal environments of the ethanol/water dual-vapour phase trigger the fast formation of oxygen-deficient vanadium oxide hydrates (VPH-VO) containing rich bound water pathways. The in situ Raman spectra verified that these bound water pathways shield the electrostatic interaction within the lamellar [VO n ] host, providing a more favourable environment for Zn 2+ diffusion. The VPH-VO cathode delivered an outstanding capacity of 452 mA h g −1 at 0.5 A/g and an excellent high-rate cycling stability of 242 mA h g −1 after 2000 cycles at 10 A/g. Density functional theory calculation disclosed the highly reversible Zn 2+ adsorption/desorption and low zinc-ion migration barrier in the bound water pathways of VPH-VO. This pioneering dual-vapour-thermal engineering is an efficient fabrication approach for superior lamellar cathode materials for high-performance AZIBs .