Researchers from the Massachusetts Institute of Technology (MIT) have developed a novel electrode material that they believe can be integrated into a semi-solid battery to store renewable energy cost-effectively.

The thick black material comprises a mixture of dispersed manganese dioxide (MnO2) particles with an electrically conductive additive in carbon black. When the mixture is pumped from the tanks toward the membrane, the carbon black reacts with a conductive zinc solution to efficiently convert chemical energy into electricity.

A rechargeable zinc-manganese dioxide (Zn-MnO₂) battery featuring this mixture was tested alongside other energy storage systems, with the team looking to see how they compared in terms of operational costs. They calculated the costs of running this semi-solid flow battery across eight, 24, and 72-hour durations. The team found that the semi-solid flow battery featuring this mixture outperformed other long-duration energy storage contenders like vanadium redox flow and lithium-ion batteries.

While other flow battery systems in contention, such as the vanadium redox flow battery, offer the storage capacity and energy density to back up megawatt and larger power systems, they depend on expensive chemical ingredients that make them bad bets for long-duration purposes.

“We performed a comprehensive, bottom-up analysis to understand how the battery’s composition affects performance and cost, looking at all the trade-offs. We showed that our system can be cheaper than others and can be scaled up,” said Thaneer Malai Narayanan, Battery and Hydrogen Researcher, MIT.

The duration of time that flow batteries can discharge, releasing the stored electricity, is determined by the volume of positively and negatively charged electrolyte solutions streaming through the stack. In theory, as long as these solutions keep flowing, reacting, and converting the chemical energy to electrical energy, the battery systems can provide electricity.

“The subsequent step is to take our battery system and construct it up,” says Narayanan. “Our analysis additionally factors the best way to different chemistries that might be developed below the semi-solid circulation battery platform, so we might be seeing this sort of expertise used for vitality storage in our lifetimes.”

Researchers at TU Graz University claimed that they had developed a redox flow battery that utilizes conventional vanillin instead of liquid electrolyte.

Scientists from Friedrich Schiller University said they had developed a new polymer electrolyte for redox flow batteries that enhances efficiency and heat-resistance capacity.