New flow battery technology could enable cheaper, more efficient energy storage

According to foreign media reports, researchers at the Massachusetts Institute of Technology have designed a new type of rechargeable fluid battery that does not rely on expensive separator membranes to generate and store electrical energy. This type of fluid battery is expected to achieve lower cost and larger-scale energy storage in the future.

The prototype flow battery produces three times more energy per square centimeter than other membrane-separated battery systems, and its power density is orders of magnitude higher than most lithium-ion batteries and other commercial and experimental energy storage systems. The device stores and releases energy by relying on a phenomenon called laminar flow, where two liquids are pumped through a channel and an electrochemical reaction between two electrodes stores or releases energy. Under the right circumstances, the solution streams through the channel, with the two liquids mixing slightly. The flow naturally separates the liquids, eliminating the need for costly battery separators.

The reactants in the battery contain a liquid bromine solution and hydrogen fuel. The research team chose bromine because the chemical is quite cheap and easy to buy, with 243,000 tons of bromine produced annually in the United States. In addition to the lower cost of bromine, the chemical reaction between hydrogen and bromine has great advantages for storing energy, but the design of fuel cells based on hydrogen and bromine will have the following situation: hydrobromic acid tends to eat away at the separator membrane of the battery, effectively slowing down the energy storage reaction and reducing the battery life.

To avoid these problems, the research team took a simple approach - removing the battery separator. Cullen Buie, associate professor of mechanical engineering at MIT, said: "This technology has great prospects for the development of electrical energy storage."

Cullen and his colleagues published their latest research in the journal Nature Communications last week. Professor Martin Bazant, a member of the research team, said: "Our latest battery system performs better than previous battery designs. We don't have to worry about the separator membrane. This is a huge breakthrough in energy storage technology."

The technology has the potential to be used in solar and wind energy storage, and low-cost energy storage could potentially drive widespread global use of renewable energy sources such as solar and wind.