Novel 3D Nanoporous Zn–Cu Alloy as Long‐Life Anode toward High‐Voltage Double Electrolyte Aqueous Zinc‐Ion Batteries

Abstract The recharge ability of zinc metal‐based aqueous batteries is greatly limited by the zinc anode. The poor cycling durability of Zn anodes is attributed to the dendrite growth, shape change and passivation, but this issue has been ignored by using an excessive amount of Zn in the past. Herein, a 3D nanoporous (3D NP) Zn–Cu alloy is fabricated by a sample electrochemical‐assisted annealing thermal method combined, which can be used directly as self‐supported electrodes applied for renewable zinc‐ion devices. The 3D NP architectures electrode offers high electron and ion transport paths and increased material loading per unit substrate area, which can uniformly deposit/strip Zn and improve charge storage ability. Benefiting from the intrinsic materials and architectures features, the 3D NP Zn–Cu alloy anode exhibits high areal capacity and excellent cycling stability. Further, the fabricated high‐voltage double electrolyte aqueous Zn–Br 2 battery can deliver maximum areal specific capacity of ≈1.56 mAh cm −2 , which is close to the level of typical commercial Li‐ion batteries. The excellent performance makes it an ideal candidate for next‐generation aqueous zinc‐ion batteries.