Trivalent Indium Ion Enabling Chemically Stable Hydrated Vanadium Oxide Cathode for Durable Aqueous Zinc Batteries

Aqueous zinc batteries (AZBs) have emerged as a promising energy storage technology due to their intrinsic safety and environmental compatibility. However, structural instability and sluggish Zn²⁺ diffusion kinetics of cathode materials hinder the development of AZBs. To address these challenges, we synthesized the cathode material In-VO by incorporating trivalent In³⁺ ions into hydrated vanadium oxide. As effective structural pillars, preintercalated In³⁺ ions can significantly expand the interlayer spacing and enhance the structural stability of In-VO, thereby enabling highly reversible Zn²⁺ insertion/extraction. In-VO cathode exhibits exceptional cycling stability of a high specific capacity of 398.7 mAh g^-1 at 0.1 A g^-1 with 92% retention over 100 cycles at 0.2 A g^-1 and remarkable rate capability of 290.5 mAh g^-1 at 5.0 A g^-1. Moreover, systematic analyses confirm the effectiveness on the suppression of vanadium dissolution and parasitic reactions. This work provides a feasible strategy for designing high-performance cathodes for advanced AZBs.