Ultra-stable zinc anode enabled by natural attapulgite-induced dual-regulation interface layer

The Zn anode in aqueous zinc-ion batteries (AZIBs) is severely hampered by uncontrolled dendrite growth and side reactions induced by aqueous electrolytes, resulting in limited cycling performance and low Coulombic efficiency (CE). Despite the fact that surface protection has proved successful in improving the stability of Zn anode, a low-cost, long-term stable material with suitable pore structure and chemical properties is still highly desirable. In this research, we have screened natural porous mineral materials based on their pore size and surface charge characteristics. Natural attapulgite (ATP) was used to construct the Zn anode interface protection layer, which was used to deposit Zn uniformly and quickly to alleviate dendrite growth and side reactions. Experimental results and theoretical calculations show that a dendrite-free Zn anode could be realized by maintaining a uniform ion flux and high ion conductivity and Zn²⁺ transfer number during the circulation with the ATP layer on the Zn anode, which could achieve a Zn anode with high CE and exceptional cyclability for more than 3,000 h at 0.5 mA cm^-2 and 0.25 mAh cm^-2. In addition, the full cell of ZnVO||ATP@Zn demonstrated prominent rate performance and long-term cycle stability, offering a sustainable and cost-effective strategy for AZIB anode protection.