In-situ constructed interface buffer layer enabled highly reversible Zn Deposition/Stripping for long-lifespan aqueous zinc metal anodes

Despite the advantages of high capacity, high safety and low cost, zinc anodes also face the inherent problems of dendritic growth, corrosion and passivation, vastly limiting the development and application of aqueous zinc ion batteries (AZIBs). Here, the epigallocatechin gallate (EGCG) was used as a hydroxyl-rich natural electrolyte additive for AZIBs. During charge–discharge process, the EGCG can be preferentially adsorbed on the zinc anode, and act as an interface buffer layer to weaken the direct contact between active water molecule and zinc anode. Based on this effect, the interface buffer layer is helped to inhibit the water-induced side reactions of hydrogen evolution, zinc corrosion and passivation, and lower the polarization overpotential, contributing to highly reversible Zn deposition/stripping behavior. As a result, the Zn||Zn symmetric batteries can maintain a stable cycling for more than 1500 h at 1.0 mA cm−2 and 1.0 mAh cm−2. Furthermore, the assembled Zn||MnO2 full batteries still delivered high capacity retention of 98.02 % after 400 cycles at 1.0 A/g. This finding enriches the design thoughts for the development of high-efficiency and practical AZIBs.