Researchers from Harvard University have developed a flow battery that uses organic compounds instead of metal ions.

Inspired by vitamin B2 that can store electricity from energy sources including solar and wind power in large batteries, the team identified the new universe of molecules which are non-toxic, non-flammable and able to be produced at low cost.

Harvard John A. Paulson SEAS Gene and Tracy Sykes Materials and Energy Technologies professor Michael Aziz said: “With only a couple of tweaks to the original B2 molecule, this new group of molecules becomes a good candidate for alkaline flow batteries.

“They have high stability and solubility and provide high battery voltage and storage capacity. Because vitamins are remarkably easy to make, this molecule could be manufactured on a large scale at a very low cost.”

The development of the new class of high-performing organic molecules follows a previous study where the Harvard researchers developed a high-capacity flow battery which can store energy in organic molecules, known as quinines, and a food additive, ferrocyanide.

However, researchers continued to explore other potential organic molecules which can provide even better performance.

Harvard University Ph.D student Kaixiang Lin said: “Now, after considering about a million different quinones, we have developed a new class of battery electrolyte material that expands the possibilities of what we can do.

“Its simple synthesis means it should be manufacturable on a large scale at a very low cost, which is an important goal of this project.”

The advancement of the project, however, could enable large-scale, inexpensive electricity storage, the team said.

The team now plans to continue to explore quinines and the new molecules to develop high-performing, long-lasting and inexpensive flow battery.