A domestic technology that cuts by 67% the production time for the core electrolyte of large-capacity energy storage systems (ESS) — used in facilities such as artificial intelligence (AI) data centers and renewable energy power plants — has been developed in Korea. Because the electrolyte can be mass-produced faster and more cheaply, the technology is expected to accelerate the deployment of large batteries that supply stable power to AI data centers or store electricity generated from solar and wind power over long periods.
KAIST said on the 5th that a research team led by Professor Kim Hee-tak of the Department of Chemical and Biomolecular Engineering has developed a process that can produce the core electrolyte of the "vanadium redox flow battery" — drawing attention as a large-capacity ESS — quickly and stably.
A vanadium redox flow battery stores a liquid electrolyte containing vanadium in a tank and circulates it to charge or discharge electricity. Unlike ordinary lithium-ion batteries, making the tank holding the electrolyte larger also increases the amount of power that can be stored. Its low fire risk and ability to be used repeatedly over long periods are also advantages.
For these reasons, it can be used as an emergency or backup power source for AI data centers, which consume large amounts of electricity and must operate around the clock. It can also store electricity produced by solar power during the day for supply at night, or gather electricity generated by wind power when winds are strong for use when generation declines. It can also be used to supply electricity when power demand at large factories or power grids suddenly surges.
The problem is the time and cost involved in making the vanadium electrolyte that serves as the battery's "fuel." Previously, the state of the vanadium had to be changed once using chemicals, and then electricity had to be run through it again to adjust it to a state suitable for battery operation. In the final process, the reaction speed dropped significantly, making it difficult to mass-produce the electrolyte.
The research team was the first in the world to reveal that when the vanadium reaches a specific state during electrolyte production, the reaction slows down sharply. It then changed the process to use a platinum-carbon catalyst instead of the existing method of using electricity from the point when the reaction slows. Rather than replacing the entire production method, the team applied a faster process only to the stage that takes the longest.
As a result, electrolyte production time was reduced by 67% from the previous level. Impurities that remain during the production process and can degrade battery performance were also removed. The same catalyst maintained its performance even after being used repeatedly more than 2,500 times, confirming its potential for application at industrial sites.
Because this technology uses an already commercialized catalyst, it can be applied to existing vanadium electrolyte production lines without building new production facilities. If production time and cost are reduced, the supply price of large-capacity ESS using vanadium redox flow batteries can also be lowered. The research team completed domestic patent registration for the related technology with Lotte Chemical and has also filed for overseas patents.
"This is an achievement that newly designed the electrolyte production process, which had been a major challenge for commercializing large-capacity batteries," Kim said. "It will be able to accelerate the commercialization of large-capacity energy storage technology needed for AI data centers and renewable energy facilities." The research findings were published in the international journal "Advanced Energy Materials" and were selected as the cover paper for Issue 34, to be released in September.
