The rapid advancement of electric vehicles and energy storage systems has highlighted the importance of battery thermal safety. Although it has garnered significant attention and been well-studied, the effect of pre-load force remains underexplored. This study emphasizes the impact of pre-load force, revealing that it can exacerbate thermal hazards and increase the gas production. However, once pre-load force exceeds 204 kgf, an extended and violent combustion reaction occurs to consume the combustible gases, mitigating the gas hazard. By combining Spearman correlation analysis and the entropy weight method to quantify this effect, indicating it significantly affects the minimum temperature rise rate and the heat accumulation, but has a lesser impact on the duration of TRP and total heat transfer, which further validates that pre-load force increases thermal hazards, while also indicating that pre-load force is not a crucial factor affecting the TRP process. In addition, based on the pre-load force sensitivity for individual batteries, it can be inferred that the impact of pre-load force can be ignored if TR propagates to the fourth battery. This work analyzes and quantifies the response sensitivity of batteries under non-standard operating conditions, laying a theoretical foundation for the assessment of battery performance and reliability analysis.

lithium-ion battery,thermal runaway propagation,prestress,sensitivity analysis