Abstract
Over the past few years, rechargeable aqueous Zn-ion batteries have garnered significant interest as potential alternatives for lithium-ion batteries because of their low cost, high theoretical capacity, low redox potential, and environmentally friendliness. However, several constraints associated with Zn metal anodes, such as the growth of Zn dendrites, occurrence of side reactions, and hydrogen evolution during repeated stripping/plating processes result in poor cycling life and low Coulombic efficiency, which severely impede further advancements in this technology. Despite recent efforts and impressive breakthroughs, the origin of these fundamental obstacles remains unclear and no successful strategy that can address these issues has been developed yet to realize the practical applications of rechargeable aqueous Zn-ion batteries. In this review, we have discussed various issues associated with the use of Zn metal anodes in mildly acidic aqueous electrolytes. Various strategies, including the shielding of the Zn surface, regulating the Zn deposition behavior, creating a uniform electric field, and controlling the surface energy of Zn metal anodes to repress the growth of Zn dendrites and the occurrence of side reactions, proposed to overcome the limitations of Zn metal anodes have also been discussed. Finally, the future perspectives of Zn anodes and possible design strategies for developing highly stable Zn anodes in mildly acidic aqueous environments have been discussed.
Highlights
It will be beneficial to review the recent studies on Zn metal anodes in mildly acidic electrolytes to provide guidelines for the development of high-performance aqueous Zn ion batteries (AZIBs)
This review summarizes the strategies for the development of high-performance AZIB
Unlike the case in alkaline systems, only Zn2+ ions are reversibly stripped/plated on the Zn metal anode surface during the battery operation in highly reversible Zn plating/stripping is possible in mildly acidic aqueous electrolytes, mildly acidic aqueous media, which is similar to the Li metal anode mechanism in lithium-ion batteries (LIBs)
Summary
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Zn-based batteries with alkaline electrolytes generally have higher energy densities than those with non-alkaline electrolytes, mildly acidic aqueous electrolytes can effectively inhibit the growth of Zn dendrites, improving the cyclic performance of the battery through highly reversible electrochemical plating/stripping of Zn2+ on the Zn anode. Comprehensive and systematic reviews on the challenges and strategies for the development of next-generation Zn metal anodes suitable for application in mildly acidic electrolytes are scarce. It will be beneficial to review the recent studies on Zn metal anodes in mildly acidic electrolytes to provide guidelines for the development of high-performance AZIBs. This review will be beneficial for the rational design of Zn metal anodes in mildly acidic aqueous systems
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
