Passive Thermal Control Strategies for Lithium-Ion Batteries under Thermal Abuse Conditions: An Experimental Study on Thermal Insulation Efficacy

Thermal abuse conditions can seriously reduce the thermal stability of lithium-ion batteries (LIBs) and even trigger thermal runaway (TR) of LIBs. This is very dangerous for electric vehicles if the TR event shows up inside the battery module. In this work, the passive control method of battery TR under the thermal abuse condition has been studied. First, thermal insulation experiments are conducted with the single-layer ceramic fiber–reinforced silica dioxide aerogel board. Results show that the 1.5-mm-thick aerogel board could not prevent TR of the battery within the heating period. But the heating time required for inducing TR is extended by 357 s. Different performance tests on the three-layer composite thermal insulation board (TTI board) are also conducted. Changing the type and thickness of metal sheets has a certain impact on the overall thermal insulation performance of TTI boards. The combination of 0.2-mm-thick copper (Cu) sheets and aerogel board in the experiment has the best thermal insulation ability. Compared with the single-layer insulation board, a TTI board reduces the maximum surface temperature of the battery by 39.18°C, a decrease of 29.96%. From a mechanistic perspective, the addition of metal sheets in the TTI board greatly reduces its absorption of thermal radiation, thereby improving the overall insulation performance.