Flow battery

E. Grinnell/Harvard Paulson School

Chemists create vitamin-powered battery

Vitamins may be good for more than strong bones and healthy bodies. They might also be good for powering batteries. In the latest version of an organic flow battery—which uses carbon-based organic compounds instead of metal ions to carry charges—scientists have introduced a molecule similar to the core of vitamin B2 to carry energy. Like other flow batteries, this one stores energy in two liquids and generates an electrical current as the liquids flow past each other, trading electrons across a membrane. Because the liquids can be housed in large tanks, these batteries have the potential to store days’ worth of energy from renewable sources such as wind and solar. The liquids typically use metals, such as vanadium, to shuttle electrons. But these metals tend to be expensive or corrosive. Organics, whether from petroleum, plants, or other places, are also good electron shuttles. Two years ago, researchers created the first organic flow battery using a compound commonly found in rhubarb. Now, the same group reports online this week in Nature Energy that it has created a similar battery with alloxazine, the backbone of B2 (above). If the new battery can be scaled up, it would be cheaper to produce than the metal variety, as the B2 compound can be readily made from common starting materials at room temperature. Plus, it would be less toxic. On par with the rhubarb battery in terms of cost, the vitamin-inspired material represents a new class of organic shuttle that might be tailored in different ways—to increase battery voltage or to pair liquids for more charge cycles, for example. But that remains to be seen. In the meantime, scientists will have to take their vitamins—and other organic compounds—to tests in the real world to see which work best.