Thermal Runaway Characteristics of LFP Batteries by Immersion Cooling

Energy storage power stations using lithium iron phosphate(LiFePO4, LFP) batteries have developed rapidly with theexpansionof construction scale in recent years. Owing to complex electrochemicalsystems and application scenarios of batteries, there is a high riskof thermal runaway (TR) and TR propagation, which may result in firesor explosions. In this work, an oil-immersed battery cooling systemwas fabricated to validate its potential function on high-safety energystorage power stations. The TR characteristics of a 125 Ah prismaticLFP battery immersed in 10# transformer oil were thoroughly investigatedvia overcharging experiments. The battery under immersion coolingwith dynamic flow of coolants displayed the highest cooling rate of0.143 & DEG;C/s compared to the static cooling (0.074 & DEG;C/s) andair cooling (0.037 & DEG;C/s). Beyond that, the constructed dynamiccooling system decreased the operating temperature of the batteryby about 3-5 & DEG;C at 1P, primarily attributing to the goodheat dissipation. Our findings indicate that the oil-immersed coolingsystem can prevent both TR of batteries and TR propagation, exhibitingattractive prospects for application in energy storage power stations.