A review on zinc electrodes in alkaline electrolyte: Current challenges and optimization strategies

As a safe, abundant and low-cost anode material, zinc (Zn) possesses the fast reaction kinetics and high energy density in alkaline environments. As a result, alkaline Zn batteries (AZBs) for example Zn-air, Zn-silver, Zn-manganese and Zn-nickel batteries have been successfully developed and commercialized. However, the Zn electrodes in these batteries still face some serious challenges, such as uneven Zn deposition, hydrogen evolution, surface passivation. To address these problems, a series of optimization strategies on the Zn electrodes are adopted, including regulating the composition, morphology and structure of Zn electrode, optimizing the electrolyte-electrode interface and compositions of electrolyte, etc. Based on the research results in the past 10 years, this review focuses on the reaction mechanisms, current challenges and adopted solutions on the alkaline Zn electrodes. Then, the research emphasis, development directions and developing suggestions of alkaline Zn electrodes are proposed. This paper can shed the light on the development of the AZBs.