Mg2+ pre-intercalated hydrated vanadium oxide as high-performance cathode for aqueous zinc-ion batteries

Aqueous zinc-ion batteries (ZIBs) have shown great potential in large-scale energy storage systems due to their economic efficiency and environmental friendliness. However, cathodes for aqueous ZIBs are affected by the slow Zn2+ diffusion kinetics and limited capacity. Herein, Mg0.17V2O5.1.7H(2)O (MgVO) nanobelt cathode with a large interlayer spacing of 13.0 A is prepared via a one-step hydrothermal approach. Furthermore, the pre-intercalated Mg2+ can stabilize the crystal structure and prevent Zn2+ from being trapped in the lattice. As a result, MgVO cathode delivers a high capacity of 386 mAh g(-1) at 0.1 A g(-1) , and impressive long-term cycling stability with a capacity retention of 91% after 1500 cycles at 5 A g(-1). Moreover, the Zn//MgVO battery can provide a high-energy density of 269 W h kg(-1) at 0.1 A g(-1) and a high-power density of 2701 W kg(-1) at 5 A g(-1). The simple preparation and low cost make this cathode show great potential in the applications of large-scale energy storage.