Reporters learned from the Dalian Institute of Chemical Physics of the Chinese Academy of Sciences on the 21st that the research team of Li Xianfeng, a researcher of the institute, has made new progress in the research of new systems of bromine based multi electron transfer liquid flow batteries. The team has successfully developed a novel bromine based two electron transfer reaction system, achieving concept validation and system scaling up of long-life zinc bromine flow batteries. The relevant results were recently published in the academic journal Nature Energy. Bromine based flow batteries rely on the redox reaction between bromide ions (Br -) and bromine elements (Br2), and have the advantages of wide resource sources, high electrode potential, and high solubility. However, the large amount of Br2 generated during the charging process can severely corrode the battery material, significantly reducing the battery's cycle life. This places higher demands on the corrosion resistance of battery materials and further increases battery costs. Although traditional bromine chelating agents can alleviate corrosion problems to some extent, the phase separation structure formed by them often leads to poor system uniformity and increases system complexity. To solve this problem, the team has developed a novel bromine double electron transfer reaction pathway. By introducing amine compounds with electron withdrawing groups as bromine scavengers in bromine electrolytes, they found that Br2 produced in electrochemical reactions can be converted into brominated amine compounds, effectively reducing the concentration of Br2 in the solution. Unlike traditional single electron transfer methods (Br - to Br0), this reaction achieves double electron transfer from Br - to Br+(bromoamine compounds), significantly improving the energy density of the battery. At the same time, the ultra-low concentration of Br2 significantly reduces the corrosiveness of the electrolyte and improves the battery life. The research team further applied this new reaction to zinc bromide flow batteries. Experiments have shown that using inexpensive and poorly corrosion-resistant SPEEK (sulfonated polyether ether ketone) membranes, batteries can still achieve long-term stable operation. In the system test amplified to the 5kW level, the battery can operate stably for over 700 cycles at 40mA cm-2, with a total lifespan of over 1400 hours and an energy efficiency of over 78%. (New Society)