• • Increasing fluorination temperature from 100°C to 250°C raises the F/C ratio and alters C–F bonding, leading to a progressive increase in heat generation in Ah-level pouch cells, with the most pronounced difference occurring in the 0–20% DOD range.
• • Highly fluorinated FPC-250 cathodes exhibit more concentrated LiF accumulation during discharge, as evidenced by post-discharge structural characterization at 20% and 80% DOD, which correlates with localized heat generation.
• • Kinetic analysis shows that FPC-250 has higher charge-transfer resistance, lower Li+ diffusivity, and a larger nucleation overpotential compared to FPC-100, resulting in stronger polarization and more severe heat generation.
• • Regulating fluorination temperature to tune the structure and chemical environment of CFx cathodes is an effective strategy for improving thermal safety, as demonstrated by the direct correlation between fluorination conditions and heat-generation behavior in practical pouch cells.