TECH FILE: Spray-Based Immersion Cooling to Boost Battery Safety

The Korea Institute of Machinery and Materials (KIMM) has unveiled what it says is the world's first spray-based immersion cooling technology for lithium-ion battery packs, a development that could improve thermal management and fire safety while dramatically reducing the amount of dielectric coolant required.

Developed by a research team led by Dr. Jinsub Kim at KIMM's Heat Pump Research Center, the system combines two cooling approaches: dielectric liquid is sprayed directly onto the tops of battery cells while the bottom portion of the pack remains partially immersed in the same non-conductive fluid. The hybrid approach enables direct heat removal through liquid contact while forced convection from the partially immersed section enhances overall cooling performance.

In testing with an actual lithium-ion battery pack operating at a 4C charge-discharge rate—representative of aggressive fast-charging conditions—the technology maintained cell temperatures below 35°C, a critical threshold for minimizing thermal degradation and reducing the risk of thermal runaway.

The most notable engineering achievement may be efficiency. Conventional immersion cooling systems require battery packs to be completely submerged, adding significant weight, cost and coolant volume. KIMM's approach reportedly reduces dielectric-liquid consumption by approximately 85%, using just 10-20% of the coolant required by traditional immersion cooling while maintaining comparable—or