Modification Strategies for Novel Cathodes in Zinc-Bromine Batteries: Review and Prospects

Zinc-bromine batteries (ZBBs) have been the focus of extensive research in distributed energy storage, primarily due to their high theoretical energy density and cost-effectiveness. Research has mainly focused on zinc anodes and electrolytes. However, the sluggish reaction kinetics of the cathode and the self-discharge induced by bromine shuttling are the main limitations in the development of ZBBs, in contrast to the issues encountered at the anode, separator, and electrolyte levels. This article reviews the challenges and solutions for ZBB cathodes, including the slow electrochemical kinetics, self-discharge, bromine toxicity and volatility, active surface area requirements of electrode materials, and corrosivity. To address these challenges, researchers are enhancing cathode materials by adding catalysts, modifying electrode structures, and immobilizing bromine, thereby improving the overall performance of ZBBs. The outlook for future research is promising, with potential advancements in catalyst balance, electrode structure stability and durability, bromine immobilization strategies, and theoretical calculations, which collectively point to achieving enhanced performance for ZBBs.