A breaktrough in flow battery technology

Researchers have found the right organic molecule to use in low cost, metal-free flow batteries, which can store the energy produced by renewable sources.

In typical flow batteries, metals like vanadium are used as liquid electrode. However, in the current study from Harvard University, naturally occurring organic molecules found in plants, animals and even oil called quinones were tested and they found the right one out of 10,000. This finding makes utilisation of wind and solar energy more favourable with much cheaper and environmentally friendly batteries.  

How it works: New organic flow battery consists of two separate tanks. There is quinone (dissolved in water) in one tank and bromine liquid (HBr/Br2) in other. To get electricity out, electrodes should be pumped to past adjoining electrodes separated by exchange membrane (Nafion 212). Each quinone molecule gives up two electrons and two protons. The electrons pass through an outside circuit to the opposite electrode and protons pass through the membrane. These partners then combine with a bromine atom to make molecules of HBr. To store the energy you should simply reverse this process.

How does flow battery work: (animation based on vanadium redox battery)

Original Paper: Nature

Abidin Balan