Dual-region synergistic modulation and (101) facet engineering for highly reversible zinc anodes

Abstract

Aqueous zinc-ion batteries (AZIBs) offer promising safety and affordability, but suffer from dendritic Zn growth and parasitic side reactions at the electrode-electrolyte interface. Herein, we construct a dual-region interfacial modulation framework by molecularly reconfiguring the Helmholtz double layer via trace methyl methacrylate (MMA). Exploiting its amphiphilic and functionally asymmetric architecture, MMA enables a coordinated interfacial reconstruction that disrupts Zn 2+ solvation in the outer Helmholtz plane, builds a chemisorbed coordination layer in the inner plane, and modulates local interfacial chemistry with spatial precision. This dual-region regulation collectively suppresses water reactivity, facilitates Zn 2+ desolvation, and drives crystallographically preferred deposition along the (101) plane, promoting lateral growth and mitigating dendrite formation. As a result, symmetric Zn||Zn cells exhibit over 4200 hours of stable cycling at 1 mA cm -2 and maintain 1100 hours of operation at 2 mA cm -2 , even at 0 °C. Zn||Ti half-cells achieve a Coulombic efficiency of 99.83%, while Zn||NH 4 V 4 O 10 full cells deliver 93.92% capacity retention after 400 cycles at 2 A g -1 , and preserve 85.3% after 300 cycles at 0 °C. This work demonstrates a scalable, mechanism-driven electrolyte design paradigm for dendrite-free and high-performance aqueous Zn metal batteries. MMA interacts with Zn 2+ in both the outer and inner Helmholtz planes, restructuring the electrolyte interface to enhance Zn 2+ desolvation and suppress parasitic reactions. Its unique molecular structure forms a stable coordination layer at the interface, reducing Zn 2+ hydration and promoting preferential deposition along the (101) crystal plane. This process effectively minimizes dendrite formation, enhancing the stability and reversibility of Zn anodes. • Methyl methacrylate (MMA) modulates both the outer and inner Helmholtz planes, suppressing parasitic side reactions. • MMA promotes preferential Zn deposition along (101) plane, enhancing lateral growth and minimizing dendrite formation. • Symmetric Zn||Zn cells exhibit over 4200 hours of stable cycling at 1 mA cm -2 and 1100 hours at 2 mA cm -2 , even under low-temperature conditions (0°C).