Achieving Stable Zinc Metal Anode Via Polyaniline Interface Regulation of Zn Ion Flux and Desolvation

Abstract

Aqueous zinc‐ion batteries feature high safety, low cost, and relatively high energy density; however, their cycle life is hindered by severe Zn dendrite formation and water‐induced parasitic reactions. Herein, a porous polyaniline (PANI) interfacial layer is developed on the surface of Zn metal anode to regulate the transport and deposition of Zn ²⁺, achieving an ultra‐stable and highly reversible Zn anode. Specifically, the abundant polar groups (NH and N) in PANI have a strong attraction to H ₂O, which can trap and immobilize H ₂O molecules around Zn ²⁺. Moreover, the protective layer regulates ion flux and deposition behavior of Zn ²⁺ through the ion confinement effect. Consequently, the Zn@PANI anode exhibits improved reversible plating/stripping behavior with a low nucleation overpotential (37.9 mV) at 2.0 mA cm ^‐2 compared to that of bare Zn anode. The MnO ₂//Zn@PANI cell demonstrates a high capacity retention of 94.3% after 1000 cycles at 1.0 A g ⁻¹. This study lays the foundation for accessible interface engineering and in‐depth mechanistic analysis of Zn anode.