Stabilizing zinc anodes for long-lifespan zinc–nickel battery through the in-situ construction of zincophilic interface layer

Abstract

Zinc–nickel batteries are identified as one of the ideal next-generation energy storage technologies because of the advantages of high safety, low cost, and excellent rate performance. However, the limited reversibility of zinc electrode caused by dendrites growth, shape change and side reactions results in poor shelf life and cycling life. To overcome these limitations, a dense and uniform ZnS coating layer is in-situ constructed on ZnO surface to improve the stability of ZnO anode. Charge migration and redistribution occur at the interface of ZnO and ZnS, and an electric field is built, which promotes the charge transfer, enabling the anode with improved reversibility and reactivity. In addition, the ZnS layer protects active zinc from bulk electrolyte, inhibiting side reactions. Moreover, the zincophilic ZnS film regulates the Zn(OH)42− ions concentration gradient and harmonizes the ions migration, mitigating the shape change and dendrites growth. These features endow the ZnO@ZnS350 electrode with stable stripping/plating cycling behavior during 1000 h at 17 mA cm−2. Furthermore, the assembled zinc–nickel battery displayed an improved storage life and a significantly extended cycling life of higher than 790 h even at a high current of 10 A (∼138 mA cm−2) and higher than 690 h at 20 A (∼276 mA cm−2), which was largely longer than that based on ZnO electrodes, demonstrating great promise in practical applications.