Micromechanical cleavage enables neat surface and organic-inorganic interlayer for reversible Zn anodes

Aqueous batteries with zinc (Zn) metal anodes offer high capacity (820 mAh g−1), intrinsic safety, and cost-effectiveness, making them attractive for large-scale energy storage. However, their limited cycle life, caused by parasitic reactions like dendrite formation and the hydrogen evolution reaction (HER), remains a major obstacle. Herein, we propose to address these issues by leveraging micromechanical cleavage (MC) approaches. The removal of Zn surface debris before cycling is achieved using commercially available adhesive tape, which eliminates sharp protrusions that are prone to generate dendrites and HER. Concurrently, the residual organic layer during the MC process, together with the in situ formed by-product (Zn4(OH)6SO4·nH2O), forms a hybrid organic/inorganic interlayer that mitigates side reactions, enhancing Zn anode reversibility and extending the cycle life by fivefold, exceeding 600 h of stable cycling. This work hints a series of pre-treatment strategies on metal anodes for achieving durable rechargeable batteries.