Towards the commercialization of rechargeable aqueous zinc ion batteries: The challenge of the zinc electrodeposition at the anode

The low efficiency of the electrodeposition of metallic zinc from mild-acidic electrolytes in realistic operating conditions currently represents the main challenge hindering the commercialization of aqueous Zn-ion batteries (ZIBs). These devices offer good environmental compatibility, low production costs, and high powder densities, thus are considered as a viable energy storage solution for stationary applications. The electrodeposition of metallic zinc is generally affected by dendrites, spontaneous evolution of gaseous hydrogen, and precipitation of insulating passivation products on the electrode surface. The recent scientific literature has provided many strategies addressing the zinc electrodeposition through the optimization of the electrode, of the aqueous electrolyte, or of the electrode–electrolyte interface. However, industrially relevant requirements such as realistic values of anode usage, current densities, and capacity limits, must be implemented in the future research studies.