Researchers at Sweden’s Linköping University have developed an organic flow battery. Principal research engineer Mikhail Vagin and his colleagues have succeeded in producing a water-based electrolyte and also electrodes of organic material, which considerably increases the energy density.
The team have used the organic conducting polymer PEDOT for the electrodes.
It is claimed this is the first redox flow battery to include organic conducting polymer electrodes operating in both the posolyte and negolyte configurations, thus the first “all‐organic” RFBs. The polymer works with a water-based electrolyte consisting of a solution of quinone molecules.
“Since both electrode, membrane and reactants are organic‐based, we can truly claim the first “all‐organic” redox flow batteries,” the scientists write in their study, which was published in the journal Advanced Functional Materials.
“Quinones can be derived from wood, but here we have used the same molecule, together with different variants of the conducting polymer PEDOT,” says principle research engineer Viktor Gueskine, one of the authors. “It turns out that they are highly compatible with each other, which is like a gift from the natural world.”
The team found that the PEDOT electrodes and quinone-based electrolytes worked together to promote the flow of protons and electrons in the battery. However, they note the battery design doesn’t offer as much energy density as versions containing vanadium.
The benefits claimed for the device are it is very cheap, entirely recyclable and perfectly safe. With the electrolyte stored externally flow batteries are easily scalable, so it would make an ideal power bank for the charging of electric vehicles or compensating for load variations on the electricity grid.
Image: A laboratory model of the first organic redox flow battery. Thor Balkhed