A lightweight 3D Zn@Cu nanosheets@activated carbon cloth as long-life anode with large capacity for flexible zinc ion batteries

Abstract Zinc metal is actively developed as the most potential next generation anode material for aqueous rechargeable batteries. However, Zn deposition and uncontrollable dendrite growth of metallic Zn anodes during cycles lead to poor cycle performance and coulombic efficiency, hindering their practical application. Constructing a three-dimensional (3D) current collector has been demonstrated to significantly inhibit the formation of zinc dendrites. Herein, a lightweight 3D flexible Zn plating/stripping scaffold, Cu nanosheets grown on activated carbon cloth (Cu nanosheets@ACC), is prepared by an electrochemical deposition technology. Compared with activated carbon cloth (ACC), Cu nanosheets@ACC current collector delivers higher special surface area and conductivity. Besides, Cu nanosheets layer not only can provide numerous, uniformly distributed Zn deposition sites but also can significantly decrease Zn nucleation overpotential. As a consequence, Zn@Cu nanosheets@ACC (Zn grown on Cu nanosheets@ACC) anode delivers a highly reversible Zn plating/stripping behavior with satisfactory cyclic stability rather than uncontrollable Zn dendrites growth. Moreover, a zinc ion battery based on the Zn@Cu nanosheets@ACC anode and MnO2@ACC (MnO2 grown on ACC) cathode presents high average coulombic efficiency (97.9%) and excellent cycling stability (94.8%) over 1000 cycles at 1 A/g as well as satisfactory mechanical properties, displaying great potential for long-life flexible zinc ion batteries.