Decoupling Parasitic Reactions From Bravais Law-Guided Electroredox Toward Highly Reversible (101)-Textured Zn Anodes for Ah-Scale Batteries.

Abstract

Aqueous Zn-ion batteries (AZIBs) are promising for grid-scale energy storage but are limited by poor Zn anode reversibility due to dendrite growth and water-driven parasitic reactions. Although crystallographic texture regulation based on Bravais law can guide Zn plating/stripping, selective facet screening often leaves unprotected facets vulnerable to the parasitic side reactions. This inherent trade-off in conventional Bravais law-based texturing strategies leads to unstable and transient texture evolution especially under practical conditions. In this study, we propose a decoupled electrolyte design that simultaneously enables facet-selective texture control and global suppression of water activity using a formamide (FA) cosolvent and a trace 1-butyl-3-methylimidazolium cation (Bmim⁺) additive. Bmim⁺ additive preferentially adsorbs on the Zn(101) facet, retarding its growth and directing Zn plating/stripping toward a (101)-textured mode, while FA suppresses the bulk/interfacial water activity, thereby suppressing interfacial side reactions on non-targeted facets. This hierarchical design ensures sustained Zn(101)-textured electroredox with markedly improved reversibility, delivering 1700 h lifespan in Zn||Zn symmetric cells at 5 mA cm^-2, 5 mAh cm^-2, and 5000 cycles in Zn||I₂ full cells with 79.55% capacity retention at 0.5 A g^-1. Notably, a 1.4 Ah pouch cell further validates the scalability of the proposed decoupling principle for practical AZIBs.