Scientists see great potential for storing renewable energy in the tanks of flow batteries. In Sweden, they have developed a new, much cleaner version of this technology, in which rare metals and synthetic polymers have been replaced by natural materials.
The reason for interest in flow batteries as an alternative to lithium-ion batteries for storing renewable energy is that they are able to store large amounts of energy at relatively low cost. While the capacity of lithium-ion batteries depends on the size of the device, flowthrough batteries can store energy in liquid electrolytes inside huge tanks for several months.
However, the production of flowable batteries requires expensive vanadium metal, which has high reliability when charging and discharging. In addition, the electrodes are usually made from synthetic polymers – carbonated polyacrylonitriles – which are environmentally friendly in production and processing. A team of scientists from Linköping University has proposed a new solution – a fully organic flow battery, writes New Atlas.
The electrodes of this battery are made of organic and electrically conductive polymer PEDOT, which is also used to create advanced lithium-ion batteries. After doping, PEDOT is able to carry positive and negative ions and interacts well with liquid electrolytes with quinone molecules.
“Quinones can be obtained from wood, but here we used the same molecule together with different variants of conductive polymer PEDOT”, – explained Victor Guskin, the author of the study. – It turns out that they are well compatible with each other – as if nature has given us a gift”.
The scientists have found that the PEDOT electrodes and quinone-based electrolytes create a flow of protons and electrons together in the battery, although they note that the energy density of their battery is not as high as that of vanadium. On the other hand, the device has proven to be very cheap in production, completely recyclable and perfectly safe, so it can be installed in houses for charging electric cars.