Experiments on the effects of immersion cooling on lithium-ion battery module and mitigating battery thermal runaway

Forced flow immersion cooling technology is considered to have great potential for application in battery thermal management systems due to its excellent heat transfer performance. However, the external liquid tank greatly reduces the energy density and the compactness of the system. Herein, a forced flow immersion cooling system without an external tank is designed to solve the complexity problem of an immersion battery thermal management system. AF-710 L coolant as the medium is selected for the experiment and six flow modes without an external liquid tank are designed to investigate its heat dissipation performance under a high discharge rate and compare it with natural air cooling and static flow immersion cooling. The results show that this forced flow immersion cooling system can control the battery temperature within 50 °C under 3C discharge. Of note, the maximum temperature in M3 mode is only 42.1 °C, and the temperature difference is controlled within 2.5 °C. In addition, the AF-710 L coolant shows good thermal barrier capability in nail-puncture tests, which can significantly reduce the temperature during thermal runaway and prevent re-ignition. The system does not require an external liquid tank, which reduces the system complexity and space requirements, improves the energy density of the battery module. Our finds can provide inspirations for development of highly-efficient thermal management systems for electric vehicles. • A tankless forced flow immersion cooling system was proposed. • Six flow modes of the same outlet but different inlets were studied. • Temperature can be controlled within 42.1 °C at 3C discharge rate. • AF-710 L coolant can control the temperature of thermal runaway within 270 °C under needle-puncture test.