Layered Structure Regulation for Zinc‐Ion Batteries: Rate Capability and Cyclability Enhancement by Rotatable Pillars

Abstract

AbstractRegulating the interlayer spacing of vanadium oxides by various pillars has commonly been used for improving zinc‐ion storage performance. However, most of the reported pillars are large and rigid, which sacrifices interlayer free volume, increases the steric hindrance, and results in large volume change. Herein, a layered vanadium oxide with –OH pillars by controllable heat treatment of layered vanadium oxide with rigid NH4+ pillars is prepared. Although the –OH pillars are small‐sized, they can firmly support the interlayers through the covalent bond. In addition, the rotatable –OH pillars can promote Zn‐ion diffusion and accommodate lattice deformation. Compared to the layered vanadium oxide with rigid pillars, the one with rotatable pillars shows a higher rate capability (321 mAh g−1 at 0.5 A g−1 and 83 mAh g−1 at 20 A g−1) and a better cyclability (93% capacity retention over 2000 cycles at 5 A g−1). Further mechanism studies demonstrate that the rotatable pillars show low‐hindrance and high‐stability to regulate the interlayer structure. It is emphasized that the interlayer microenvironment can not be neglected, but is crucial for advanced electrodes of aqueous zinc‐ion batteries, rather than pursuing larger interlayer spacing.