Abstract: High-temperature ejecta generated during the thermal runaway process of lithium batteries can compromise the structural integrity of the top plate of the battery pack, posing a severe thermal shock threat to surrounding equipment, wiring, and aircraft structures. This threat is particularly critical in aviation, where ensuring the safety of electrical systems and components is crucial. To investigate the effects of thermal runaway on lithium batteries in a controlled experimental environment, a battery thermal shock containment platform was built. This study evaluates the impact of thermal runaway on the top plate of the battery pack at different states of charge (SOC) and compares the passive protective effects of organic and inorganic fire-resistant coatings under extreme conditions. Furthermore, it explores the potential for weight reduction in the battery pack structure following the application of these coatings. The experimental results reveal a strong correlation between the SOC and the severity of thermal runaway effects. Specifically, higher SOC values increase the risk of catastrophic failure. When a battery at 100% SOC undergoes thermal runaway, a 1.0-mm-thick aluminum plate is punctured upon impact, whereas a 1.5-mm-thick plate remains intact, achieving effective containment. The study demonstrates that applying fire-resistant coatings to the top plate of the battery pack considerably enhances its structural integrity under high-temperature shocks induced by thermal runaway. Organic coatings E85S15B3 and E80S20, along with inorganic coating APB3, reduced the peak surface temperatures of the plates by 93.8%, 90.7%, and 90.0%, respectively. Moreover, this study examines the effect of structural plate thickness on thermal insulation. Increasing the plate thickness from 1.5 to 3.0 mm improves thermal insulation, providing additional protection against high-temperature conditions. The protective effect of a 3.0-mm-thick uncoated top plate was found to be similar to that of a 1.0-mm-thick top plate coated with a 0.5-mm layer, indicating that a thin coating has a comparable performance to that of a thick plate; this makes it applicable in weight-saving designs. Experimental plates coated with E85S15B3 and E80S20 weighed 145.6 and 150.8 g, respectively, reflecting weight reductions of 247.4 and 242.2 g compared with uncoated 3.0-mm-thick plates, corresponding to weight reductions of 62.95% and 61.63%, respectively. The plate coated with APB3 weighed 148.6, 244.4 g lighter than the uncoated 3.0-mm-thick plate, achieving a weight reduction of 62.19%. These results indicate the potential of fire-resistant coatings to enhance the thermal safety and lightweighting of battery pack structures. This study provides valuable theoretical and experimental data to support the development of safer and lighter lithium battery systems for aviation applications. The findings have significant implications for battery pack design, reinforcing the importance of coating technologies in enhancing the safety and performance of aviation lithium battery systems.