The development builds on previous work in which the team developed a high-capacity flow battery that stored energy in organic molecules called quinones and a food additive called ferrocyanide instead of metal ions such as lithium. These resulted in high-performance, non-flammable, non-toxic, non-corrosive, and low-cost chemicals that could enable large-scale, inexpensive electricity storage in flow batteries.
These store energy in solutions in external tanks — the bigger the tanks, the more energy they store. The team found inspiration in vitamin B2, which helps to store energy from food in the body. The key difference between B2 and quinones is that nitrogen atoms, instead of oxygen atoms, are involved in picking up and giving off electrons.
“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,” said Kaixiang Lin, a Ph.D. student at Harvard and first author of the paper in Nature Energy. “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."
“With only a couple of tweaks to the original B2 molecule, this new group of molecules becomes a good candidate for alkaline flow batteries,” said Michael J. Aziz, the Gene and Tracy Sykes Professor of Materials and Energy Technologies at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS). “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.”
Harvard’s Office of Technology Development has been working closely with the research team to build relationships with companies well positioned to commercialize the new chemistries.