Natural Mineral Engineering of Zinc Anode: Attapulgite-Based Interfacial Modification for Dendrite-Free Aqueous Zinc-Ion Batteries

Abstract

The zinc metal anode demonstrates advantageous characteristics including high theoretical specific capacity, low polarization, and favorable redox potential. However, its actual implementation is constrained by obstacles including dendrite formation and corrosion surface passivation. This study investigates three natural mineral materials, namely diatomite (DTM), Na+-montmorillonite (NaMMT), and attapulgite (ATP), as protective coatings for zinc anode modification. Among these, the ATP coating exhibits superior performance. Post-cycle SEM analysis of the ATP-Zn anode reveals minimal byproduct formation. At 0.25 mA cm-2 and 0.05 mAh cm-2 , symmetric cells with the improved anode have a longer cycle life of more than 1200 hours. At 2 mA cm-2 and 1 mAh cm-2 , asymmetric cells sustain a steady Coulombic efficiency (CE, average 99.1%) for 200 cycles. Full-cell experiments further demonstrate exceptional rate capability and cycling stability. The superior performance of ATP-modified zinc anode originates from its unique nanorod-like microstructure and surface functional groups, which synergistically facilitate uniform Zn ion (Zn2+) flux distribution and suppress dendritie growth through selective ion transport channels and enhanced interfacial stability. These findings provide both theoretical insights and practical solutions for applying natural mineral materials in aqueous zinc-ion battery systems.