'Water-Soaked' Battery Commercialized Next Year... "No More Fire Worries"

Ulsan National Institute of Science and Technology Research Team Begins Prototype Development

Schematic diagram of the prototype equipped with the WIB system designed by the research team

[Asia Economy Reporter Kim Bong-su] A battery that operates underwater and completely eliminates the possibility of fire has been developed.

Ulsan National Institute of Science and Technology (UNIST) announced on the 17th that Professor Kim Young-sik's team from the Department of Energy and Chemical Engineering, in collaboration with Korea East-West Power and Korea Testing Certification (KTC), has begun product development for the commercialization of the "Water-in Battery (WIB)".

This battery operates in water containing a special fire-retardant substance. In other words, the battery materials are immersed in a solution dissolved with fire-retardant substances. During normal operation, it lowers the battery's temperature to extend its lifespan, and if thermal runaway occurs, the fire-retardant substance on the surface penetrates to block oxygen and heat, thereby extinguishing the fire early.

At the meeting, cooperation plans for the development and demonstration of the WIB system were discussed. The participating organizations will collaborate to design, manufacture, build, and demonstrate a 100kWh-class ESS system equipped with WIB technology. The goal is to operate an explosion-free ESS-based electric vehicle charging station linked with renewable energy.

Professor Kim Young-sik explained, “In the past five years alone, about 30 ESS fires have been reported domestically, raising awareness of battery fire issues. We have been considering solutions to this problem. Inspired by the safety of seawater batteries operating underwater and cases of fire suppression for electric vehicle fires using immersion extinguishing, we developed a battery system that operates in fire-retardant substances.”

The research team obtained the idea for the WIB system during the development of seawater batteries and marine-specialized batteries as part of a regional revitalization project supported by the Ministry of Trade, Industry and Energy and Ulsan Metropolitan City, and successfully realized it.

The team also directly verified the system's performance through thermal runaway tests using ESS modules they manufactured themselves. In experiments conducted at the Korea Testing Laboratory (KTL), the ESS applying WIB technology showed no explosions or secondary fire propagation compared to conventional ESS. Based on these results, the researchers published the WIB system concept in international academic journals and secured multiple related fundamental patents.

The research team, through their startup FortyOne, collaborated with Korea East-West Power to produce WIB prototypes and participate in manufacturing. After about one year of demonstration, they aim to launch commercial products in the second half of next year.