Shown above is the KAIST campus in South Korea. Its research team has developed a cheap and safe redox flow battery. Photo courtesy of KAIST

Korean university team works on alternative battery techs

A team of researchers at the Korea Advanced Institute of Science and Technology (KAIST) announced on March 23 that they had developed a cheap and safe redox flow battery.

The team headed by Prof. Byon Hye-ryung and Prof. Baik Mu-hyun said that their development would help the redox flow battery take a center stage in the world.

The redox flow battery can be used as new and renewable energy as well as for energy storage system thanks to their low cost, low flammability, and long lifetime of longer than 20 years.

But there is a problem; the price of vanadium, which is most widely used as active material for redox flow batteries, has shot up in recent years.

This prompted scientists to search for redox materials to replace it and the KAIST team developed a highly soluble and stable organic redox-active molecule for use in aqueous redox flow batteries.

Toward that end, the KAIST research team has focused on developing aqueous redox flow batteries by redesigning an organic molecule.

It is possible to control the solubility and electrochemical redox potential of organic molecules by engineering their design, which makes them a promising active material candidate with possibly higher energy storage capabilities than vanadium, according to KAIST.

“We have demonstrated the principles of molecular design by modifying an existing organic active molecule with low solubility and utilizing it as an active molecule for redox flow batteries. We have also shown that during a redox reaction, we can use molecular interactions to suppress the chemical reactivity of radically formed molecules,” Prof. Byon said.

“Should this be used later for aqueous redox flow batteries, along with its high energy density and high solubility, it would also have the advantage of being available for use in neutral pH electrolytes.”

She also noted that vanadium redox flow batteries currently use acidic solutions, which cause corrosion, and we expect our molecule to solve this issue.

“Since existing lithium ion-based ESS are flammable, we must develop safer and cheaper next-generation ESS, and our research has shown great promise in addressing this,” she said.