Unveiling Electrode–Electrolyte Interface Dynamics for Aqueous Zn Batteries

Aqueous Zn batteries are a promising solution for energy storage due to their safety and cost-effectiveness. However, conventional Zn anodes face challenges such as slow interfacial kinetics and structural collapse at high rates and Zn utilization. Here, we design an integrated Zn anode with an embedded heterophase boundary framework (HPF-Zn) that could regulate the chemical environment and charge transport kinetics for uniform, fast Zn deposition. Well-designed in situ Raman spectra clearly visualize the dynamic interface evolution under various conditions, confirming rapid Zn2+ replenishment at the interface for HPF-Zn anode. Consequently, the HPF-Zn anode achieves 60× the cycle life of conventional Zn anodes with nearly 100% Zn utilization. Zn||V2O5 full cells exhibit excellent cycling stability, retaining 80% capacity over 5500 cycles (N/P = 5.6) and 2500 cycles (N/P = 3.2). Moreover, Ah-level pouch cells demonstrate superior durability. This work advances our understanding of dynamic interfaces and highlights a strategy for stabilizing electrode–electrolyte interfaces via heterophase boundary design.