Saturday, May 28, 2022

Developing redox flow batteries as a viable energy storage system

Could we be close to having sustainable, continuously rechargeable batteries that power our lives?

Associate Professor, Aaron Marshall, is working towards developing a stable, reliable, cost-effective redox flow battery alternative to the traditional Lithium-ion (Li-ion). He is developing redox flow batteries that promise to act as a viable energy storage system.

According to Marshall, most of the electricity is not used during daylight hours. Thus, a reliable, stable way of storing energy is required.

The energy stored in Li-ion batteries interacts with and absorb into the solid electrodes. This causes physical changes in electrodes, i.e., electrodes expand and contract during the charging and discharging process. The continuous changing of the physical structure in a Li-ion battery, in the end, destroys the electrodes, to the point where they can’t absorb as much energy.

After some time you might probably charge your battery to half and, because it’s not effectively recyclable, the average consumer replaces the battery.

Unlike conventional Li-ion battery, the redox flow batteries don’t change. Instead, the system uses tanks of liquid, made up of metals dissolved in a solution, which is charged and discharged. Also, redox flow batteries don’t lose charging capacity over time because the solution doesn’t wear.

Marshall said, “This makes redox flow batteries sound very attractive, but there are challenges to making it a viable option. One challenge to redox flow batteries at this stage is how slow the battery can be charged and discharged. To release a comparable amount of power as Li-ion batteries, the flow battery electrodes need to be big – impractically big.”

“We are working towards developing a more viable system. If we can halve the size of the electrodes by doubling the speed of the reaction, then we can reduce the cost. If we can make a cheaper system that is comparable in price to a Li-ion battery, but lasts at least twice as long and is more stable, wouldn’t that be attractive?”

“And the most exciting part is, we are only scratching the surface. These batteries could be cheap and robust solutions to large-scale energy storage.”

“Redox flow batteries are already used as nuclear power backup because of the stability and reliability to store and not lose power over long periods, but I think over the next four to five years this type of system will become much more common.”


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