Rational Design of V<sub>2</sub>O<sub>5</sub>/VOPO<sub>4</sub> Heterostructure Cathode Inducing Interface Optimization for High-Rate and Long-Cycling Aqueous Zinc-Ion Batteries.

Deng, Shiyao; Yan, Xuemin; Jiang, Yu; Ding, Fengyue; Li, Aixin; Zhang, Ruijie; Qu, Yongheng; Xie, Zhizhong et al. · Nano Lett · 2025

basic_science · Level V

Where this comes from

Abstract

Aqueous zinc-ion batteries (AZIBs) represent an environmentally benign energy storage alternative. However, the V<sub>2</sub>O<sub>5</sub> cathode suffers from limited cycling stability and rate capability due to structural instability, vanadium dissolution, and high desolvation energy caused by the large size of [Zn(H<sub>2</sub>O)<sub>6</sub>]<sup>2+</sup> deintercalation. Address these issues, we introduce a V<sub>2</sub>O<sub>5</sub>/VOPO<sub>4</sub> (VOP) heterostructure that that reinforces the crystal structure to suppress vanadium dissolution and establishes a hydrophilic interface reducing the desolvation energy of Zn<sup>2+</sup>. The heterostructure additionally generates an internal electric field boosting Zn<sup>2+</sup> kinetics, synergistically enhancing the rate performance. Density functional theory calculations and in situ X-ray diffraction elucidate the operating mechanism, while a suite of ex situ characterizations confirms improved structural stability, dissolution resistance, and electrochemical performance. The optimized VOP heterostructure achieves a remarkable capacity retention of 194.8 mAh g<sup>-1</sup> after 4000 cycles at 10 A g<sup>-1</sup>, underscoring its effectiveness in bolstering the cathode's performance for AZIBs.