New research holds promise for cheaper, more efficient grid-scale batteries

Scientists at the Pacific Northwest National Laboratory (PNNL) have developed a new organic material that holds the potential to make grid-scale redox flow batteries cheaper and more efficient.

Using an organic molecule that appears in dyes and antibiotics, PNNL researchers have developed a water-soluble, phenazine-based material that’s highly reversible. The material could serve as a less expensive alternative to vanadium-based electrolyte solutions used to store energy in many grid-scale redox flow batteries.

“This is a major development for organic flow batteries,” Imre Gyuk, the director of energy storage at the U.S. Department of Energy Office of Electricity, which supported the PNNL research, said. “There is much interest around the potential for water-soluble, organic redox materials as an alternative to vanadium-based batteries. However, the problem is getting the materials to actually dissolve in water and maintain the desired electrochemical properties.”

Wai Wang, a chief scientist, led the PNNL research team in developing a process to chemically modify the organic compound phenazine, producing a water-soluble derivative with maximized redox capabilities. Wang has described the process as “straightforward and scalable.”

“The results are promising,” Wang said. “We have not only developed a viable alternative to vanadium, we have developed a structured, virtual screening approach that will help us identify new promising materials.”

The PNNL research team will conduct a cost analysis, but phenazine precursor chemicals are widely available and affordable. Given that vanadium is a commodity material often used to make steel, its price and availability are more variable and subject to supply and demand.