Sweden develops organic redox flow battery with large capacity to power electric vehicles

According to foreign media reports, researchers at the Organic Electronics Laboratory at Linköping University in Sweden have demonstrated for the first time an organic battery called a "redox flow battery" with a large capacity that can be used to store energy from wind turbines and solar cells, and can also be used to power cars.

Battery researchers (Image credit: Linköping University)

A redox flow battery is a stationary battery in which the energy is located in an electrolyte outside the cell, the same as a fuel cell. It is often marketed with the prefix "eco" because it can store surplus energy such as solar and wind energy. In addition, it can be recharged an unlimited number of times. However, redox flow batteries usually contain a rare and expensive metal, vanadium, and the electrolyte that stores energy is usually a water-based electrolyte, which makes the battery safer to use, but reduces the energy density.

The researchers have now succeeded in not only producing a water-based electrolyte, but also using organic materials to make electrodes, which can greatly increase the energy density of the battery. Ultimately, a fully organic redox flow battery can be made to store solar and wind energy and compensate for imbalances in grid supply.

The researchers doped the conductive polymer PEDOT to make electrodes for the transport of positive and negative ions. This water-based electrolyte is made from a solution of quinone molecules, which can be extracted from forest materials. The high compatibility means that the PEDOT electrode can help the quinone molecules switch between oxidized and reduced states, and in this way can generate proton and electron flows.

At present, the energy density of this organic redox flow battery is still lower than that of vanadium-containing batteries, but it is cheaper, recyclable, safe, and can store energy and balance the power grid. In the future, this organic redox flow battery can also charge electric vehicles at home .