Synergistic Effects of an In Situ-Polymerized Polyaniline Interfacial Layer with Steric Hindrance for Stable and Dendrite-Free Zinc Anodes

Abstract

Aqueous zinc-ion batteries are promising for large-scale energy storage due to their high safety, low cost, and relatively high energy density. However, their commercialization is seriously hindered by side reactions such as zinc dendrite growth, zinc corrosion, and hydrogen evolution. In this paper, a polyaniline (PANI) interface layer modified zinc anode (PANI@Zn) is constructed. This layer serves three functions: its high specific surface area and excellent wettability promote Zn2+ migration; it homogenizes the electric field to suppress zinc dendrite growth; and the steric hindrance from phytic acid limits water diffusion, increasing the hydrogen evolution overpotential. As a result, symmetrical cells with PANI@Zn achieve stable cycling for 1700 h at 1 mA cm−2/0.5 mAh cm−2 and 550 h at 3 mA cm−2/1.5 mAh cm−2. Full cells paired with a MnO2 cathode deliver 340.1 mAh g−1 at 0.2 A g−1 and retain 75.4% capacity after 1000 cycles at 1 A g−1. A high-mass-loading pouch cell further demonstrates practical viability, achieves 0.468 Ah at 69.4 mA g−1 and stable cycling over 500 cycles at 62.5 mA g−1. This research offers a synergistic design for zinc anodes that simultaneously mitigates three major issues.