Promoting Zinc Plating and Silencing the Hydrogen Evolution Reaction through Spatial Decoupling for Durable Aqueous Zinc-Ion Batteries.

Wu, Zhenrui; Wang, Hao; Saneifar, Hamidreza; Hansen, Evan J; Mir, Rameez A; Woods, Eric; Schwab, Christian; Finsterbusch, Martin et al. · ACS Nano · 2026

basic_science · Level V

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Abstract

An aqueous Zn-ion battery (AZIB), with its safety and cost benefits, is a promising technology for grid-scale energy storage applications. However, side reactions, such as the hydrogen evolution reaction (HER), occur synchronously with Zn plating, causing anode irreversibility and constituting a fundamental limitation of AZIBs. Herein, we propose a spatial decoupling strategy, using post-transition metal halide as an electrolyte additive to construct <i>in situ</i> microheterogeneity at the anode interface so as to decouple such synchronicity, promoting Zn plating while silencing the HER with solvating H<sub>2</sub>O "hopping" to the anchored halide anion. The work function of post-transitional metals and the polarizability of halide anions are key features in constructing such fast Zn<sup>2+</sup> conducting channels. As a result, using InBr<sub>3</sub> enhances the accumulated capacity of a Zn||Zn cell by 64 times from 0.074 to 4.8 Ah cm<sup>-2</sup>, the cycle life of a V<sub>2</sub>O<sub>5</sub>||Zn battery by 100 times from 10 to >1000 cycles, and the stable capacity of a Mn<sub>2</sub>V<sub>2</sub>O<sub>7</sub>||Zn battery by 70% from 83 to 141 mAh g<sup>-1</sup>. We further introduce a feature matrix predicting efficient post-transitional metal cation and halide anion combinations to enhance the reversibility of metal deposition-dissolution reactions. This framework can be generalized to advance other battery chemistries both practically and mechanistically.