Impact of Bromine Complexing Agents and Battery Construction on Hydrogen–Bromine Redox Flow Battery Performance

Hydrogen–bromine redox flow batteries (HBFBs) offer significant advantages in energy storage, including high energy capacity, efficient round-trip conversion, and low cost, positioning them as optimal solutions for grid applications. However, HBFBs are susceptible to issues such as self-discharge, the bromine shuttle effect, high Br2 vapor pressure, poisoning, and corrosion. Bromine complexing agents (BCAs) have been employed to mitigate these challenges, albeit with drawbacks such as reduced electrolyte conductivity, catalyst site blockage, and diffusion limitation. This review explores the impact of BCAs on the performance of HBFBs, focusing on cell structures such as electrolytes, membranes, and electrodes. Recent research progress in membrane materials and Pt catalysts is summarized to address these issues, and future prospects and challenges for high-performance HBFBs development are discussed.