Synergistic Modulation of Mass Transfer and Parasitic Reactions of Zn Metal Anode via Bioinspired Artificial Protection Layer

Rechargeable aqueous zinc-ion batteries are regarded as promising energy storage devices due to their attractive economic benefits and extraordinary electrochemical performance. However, the sluggish Zn2+ mass transfer behavior and water-induced parasitic reactions that occurred on the anode-electrode interface inevitably restrain their applications. Herein, inspired by the selective permeability and superior stability of plasma membrane, a thin UiO-66 metal-organic framework layer with smart aperture size is ex-situ decorated onto the Zn anode. Experimental characterizations in conjunction with theoretical calculations demonstrate that this bio-inspired layer promotes the de-solvation process of hydrated Zn2+ and reduces the effective contact between the anode and H2O molecules, thereby boosting Zn2+ deposition kinetics and restraining interfacial parasitic reactions. Hence, the Zn||Zn cells could sustain a long lifespan of 1680 h and the Zn||Cu cells yielded a stable coulombic efficiency of over 99.3% throughout 600 cycles under the assistance of the bio-inspired layer. Moreover, pairing with & delta;-MnO2 cathode, the full cells also demonstrate prominent cycling stability and rate performance. From the bio-inspired design philosophy, this work provides a novel insight into the development of aqueous batteries. Inspired by the function of cell membrane ion channels, a porous and robust UiO-66 interfacial layer is decorated on the Zn anode. Benefiting from the unique aperture limiting effect, the artificial layer can boost ion mass transfer and hinder parasitic reactions, thereby enhancing the reaction kinetics and thermodynamic stability of the Zn anode.image