Harvard researchers have developed a battery that harnesses energy by using the electrochemistry of organic molecules rather than metals. The battery, which they say can be applied on a power-grid scale, uses naturally abundant and small organic compounds called quinones rather than electrocatalysts from costly precious metals such as platinum.
Quinones would be inexpensive to obtain and can be found in green plants or synthesized from crude oil. The battery designed by Harvard scientists and engineers used a quinone molecule that's almost identical to one that's found in rhubarb.
Unlike solid-electrode batteries, flow batteries are recharged by two chemical components dissolved in fluids that are kept in separate tanks. Flow batteries are well suited to storing large amounts of energy, but a major drawback to metal-based flow cells has been cost.
According to MIT Technology review, a conventional metal-reliant flow battery costs an estimated $700 per kilowatt-hour of storage capacity, whereas the Harvard team's metal-free technology would bring those costs down to $27 per kilowatt-hour.
"The whole world of electricity storage has been using metal ions in various charge states, but there is a limited number that you can put into solution and use to store energy, and none of them can economically store massive amounts of renewable energy," said Roy G. Gordon, one of the researchers who helped screen more than 10,000 quinone molecules to find the best candidate for the novel battery.
"With organic molecules, we introduce a vast new set of possibilities. Some of them will be terrible and some will be really good. With these quinones we have the first ones that look really good."