Homogeneous deposition of zinc on three-dimensional porous copper foam as a superior zinc metal anode

Metal zinc, with the advantages of low-cost, low redox potential and high capacity, is an ideal anode for aqueous zinc-ion batteries. Nonetheless, the inferior plating/stripping Coulombic efficiency and poor reversibility hinder its practical applications. To address the drawbacks, zinc nucleation overpotential of different substrates is systematically investigated in asymmetric cells for the first time to confirm the suitable substrate with highly reversible plating/stripping behavior. As a result, Cu foam presents the low zinc nucleation overpotential of 65.2 mV and superior plating/stripping Coulombic efficiency close to 100 %. Meanwhile, Cu foam is optimized as the carrier for deposition of metallic zinc and preparation of Zn@Cu foam anode through electrochemical deposition method. Besides, Zn@Cu foam anode holds the low initial polarization voltage and stable voltage hysteresis profile with negligible voltage polarization in symmetric cell. Furthermore, coupled with β-MnO2 cathode, it could exhibit a...