Van der Waals Interaction-Driven Self-Assembly of V2O5 Nanoplates and MXene for High-Performing Zinc-Ion Batteries by Suppressing Vanadium Dissolution.

Abstract

Aqueous zinc-ion batteries (AZIBs) are attractive energy storage devices that benefit from improved safety and negligible environmental impact. The V2O5-based cathodes are highly promising, but the dissolution of vanadium is one of the major challenges in realizing their stable performance in AZIBs. Herein, we design a Ti3C2Tx MXene layer on the surface of V2O5 nanoplates (VPMX) through a van der Waals self-assembly approach for suppressing vanadium dissolution during an electrochemical process for greatly boosting the zinc-ion storage performance. Unlike conventional V2O5/C composites, we demonstrate that the VPMX hybrids offer three distinguishable features for achieving high-performance AZIBs: (i) the MXene layer on cathode surface maintains structural integrity and suppresses V dissolution; (ii) the heterointerface between V2O5 and MXene enables improved host electrochemical kinetics; (iii) reduced electrostatic repulsion exists among host layers owing to the lubricating water molecules in the VPMX cathode, facilitating interfacial Zn2+ diffusion. As a result, the as-made VPMX cathode shows a long-term cycling stability over 5000 cycles, surpassing other reported V2O5-based materials. Especially, we find that the heterointerface between V2O5 and MXene and lubricated water molecules in the host can achieve an enhanced rate capability (243.6 mAh g-1 at 5.0 A g-1) for AZIBs.