Ultra-thin Zn with preferential crystal plane for aqueous zinc-metal batteries

Dendrite growth, corrosion and side reactions have always been stumbling blocks for the commercialization of aqueous zinc-metal batteries. In order to carry forward the advantages of low-budget of aqueous zinc-metal batteries (AZMBs), it is necessary to improve the utilization rate of Zn anode, that is, to modify the thinnest possible Zn anode to enhance its cycling performance. To address this goal, the ultrathin (20 μm) zinc foil was modified by acid etching with sulfamic acid. The Zn anode prepared by this method has the improved wettability between the electrode and the electrolyte, which facilitates the transport of zinc ions across the interface. In addition, this method can significantly improve the ratio of I (002) /I (100) on the surface of Zn anode, which can induce zinc ions to deposit along the horizontal direction and greatly reduce the anomalous formation of zinc dendrites. It is demonstrated that SAZ@Zn//SAZ@Zn symmetric cell stably cycles for 2428 h at a current density of 1 mA cm -2 , and the SAZ@Zn//K 0.54 V 2 O 5 full cell maintains a high discharge specific capacity of 205.1 mAh g -1 after 2340 cycles at a large current density of 5 A g -1 . More importantly, the SAZ@Zn//K 0.54 V 2 O 5 pouch cell maintains 96.5 % capacity retention rate (relative to the initial capacity) at a current of 5 A g -1 for 1500 cycles. The outstanding performance of the strategy indicates that the ultra-thin Zn anode has an important application in the energy storage of AZMBs. • The 20 μm ultrathin zinc foil was surface-modified through acid etching using sulfamic acid. • SAZ@Zn anode has the improved ratio of I (002) /I (100) . • The as-prepared symmetric cell stably cycles for over 2400 h at 1 mA cm -2 . • The as-prepared pouch cell maintains 96.5 % capacity retention rate at a current of 5 A g -1 for 1500 cycles.