Superior cycling stability of H0.642V2O5·0.143H2O in rechargeable aqueous zinc batteries

To increase the service life of rechargeable batteries, transition metal oxide hosts with high structural stability for the intercalation of carrier ions are important. Herein, we reconstruct the crystal structure of a commercial V 2 O5 by pre-intercalating H + and H 2 O pillars using a facile hydrothermal reaction and obtain a bi-layer structured H 0.642 V 2 O 5 ·0.143H 2 O (HVO) as an excellent host for aqueous Zn-ion batteries. Benefiting from the structural reconstruction, the irreversible “layer-to-amorphous” phase evolution during cycling is considerably less, resulting in ultra-high cycling stability of HVO with nearly no capacity fading even after 500 cycles at a current density of 0.5 A g −1 . Moreover, a synthetic proton and Zn 2+ intercalation mechanism in the HVO host is demonstrated. This work provides both a facile synthesis method for the preparation of V-based compounds and a new viewpoint for achieving high-performance host materials.