Spatially homogeneous copper foam as surface dendrite-free host for zinc metal anode

[Display omitted] •Novel Cu foam@Zn anodes with 3D structure are prepared via electroplating.•Cu foam@Zn anode could alleviate the uneven deposition issue on anode side.•Cu foam@Zn displays high capacity and excellent cyclability when paired with β-MnO2 cathode.•Self-discharge test confirms the stability of Cu foam@Zn in mild acid electrolyte. Aqueous zinc-ion batteries (ZIBs) are attractive energy storage technology due to merits of high safety, low-cost and environment-friendliness. However, the further development of aqueous ZIBs is plagued by severely uneven zinc deposition on the anode side, which leads to low Coulombic efficiency and formation of dendrites. In this work, novel anodes are prepared by electroplating zinc on different substrates (copper foam, copper foil and Ni foam), namely, Cu foam@Zn, Cu foil@Zn and Ni foam@Zn, respectively. As a result, Cu foam@Zn is screened as optimal anode, for Cu foam@Zn anode exhibits small voltage hysteresis, high Coulombic efficiency and negligible self-discharge. Moreover, the assembled Cu foam@Zn|β-MnO2 cell shows good cycle stability (206.9 mA h g−1 after 500 cycles at a current density of 1 A g−1) and excellent rate performance. This superior electrochemical performance could be attributed to the three-dimensional porous architecture, superb electrical conductivity and good corrosion resistance of Cu foam@Zn anode, guaranteeing its faster electrochemical kinetics, more uniform zinc deposition and stable cyclability.