Zinc–nickel batteries (ZNBs) are a promising energy storage technology owing to their high output voltage, inherent safety, and cost‐effectiveness. However, their practical application is limited by zinc‐anode instability in alkaline electrolyte, which leads to performance‐degrading dendrite growth and passivation. To address this issue, we introduce an electropolymerized polypyrrole (PPy) film as a multifunctional artificial solid electrolyte interphase to stabilize the anode. The PPy layer facilitates the desolvation of OH − ions during discharge, enhancing reaction kinetics, while simultaneously restricting the diffusion of Zn(OH) 4 2− ions into the bulk electrolyte, thereby mitigating dendrite growth and anode passivation. Consequently, a full battery incorporating the protected anode with a Ni(OH) 2 cathode (ZnO@PPy||Ni(OH) 2 ) exhibits exceptional performance. Operating with a low electrolyte‐to‐capacity (E/DC) ratio of 0.05 mL mAh −1 and a high depth of discharge of 100%, the battery delivers 565 mAh g −1 after 245 stable cycles at 1 C. Moreover, when charged at 1 C and discharged at 10 C, it maintains 620 mAh g −1 over 340 cycles, with capacity retention of 94%. This work presents a simple and effective strategy for developing protective layers for Zn‐based anodes, offering a new design paradigm for engineering active electrode–electrolyte interphases to enable high‐performance ZNBs.
Sun et al. (2026) studied this question.