Work

Modulating Zn 2+ Coordination Strength and Interfacial Mobility via Tailored Phenolic Additives for High Performance of Aqueous Zn‐Metal Batteries

Year: 2025

Type: article

Abstract: Aqueous Zn‐metal batteries (AZMBs) are promising candidates for next‐generation energy storage. For achieving highly reversible Zn anodes by controlling interfacial Zn 2+ diffusion, the targeted exploration of electrolyte additives is crucial. Conventional additives typically exhibit strong coordination with Zn 2+ , which mitigates concentration polarization for planar deposition, but can also cause Zn 2+ retention and uneven dissolution during stripping. This study introduces weakly coordinating additives to achieve a balanced regulation of Zn plating and stripping. By investigating a series of para‐substituted phenols, it is demonstrated that weakly coordinating phenolic additives retain the ability to concentrate solvated [Zn(H 2 O) 6 ] 2+ at the interface, thereby mitigating concentration polarization. Both experimental and computational results confirm that the reduced coordination strength enhances interfacial Zn 2 ⁺ mobility, ensuring a uniform Zn 2+ distribution at the electrode–electrolyte interface. Among the investigated additives, the p‐hydroxyacetophenone (ACETO) exhibits optimal performance, enabling ZnǁZn symmetric cells to achieve an exceptional cycling stability (1281 h at 5 mA cm −2 and 5 mAh cm −2 ) and a high‐rate capability. Furthermore, Zn ǁ I 2 batteries containing ACETO retain 89.5% of their capacity after 2700 cycles. This work establishes weakly coordinating additives as a viable strategy and provides a new design principle for regulating interfacial Zn 2 ⁺ dynamics.

Source: Advanced Functional Materials

DOI: 10.1002/adfm.202527096