Abstract The increasing demand for Li-ion batteries in electric vehicles, electronics, and drones underscores the critical need for effective thermal management to prevent performance degradation. While extensive research exists on cooling methods, a significant gap remains regarding the direct impact of surface temperature gradients on discharge duration. This study experimentally investigates the discharge performance of a LiFePO4 pouch cell by analyzing its surface temperature distribution. The cell was discharged at rates from 0.5C to 2.5C under varying convective cooling conditions. This study prioritizes discharge performance because low-power two-wheeler EVs and drones experience high thermal stress during discharge. Using IR thermography, we precisely mapped surface and tab temperatures to locate hotspots and quantify thermal non-uniformity. Key findings reveal that increasing air flow from 0.0054 m3/s to 0.0189 m3/s effectively limits the surface temperature gradient to below 5°C, mitigating thermal hotspots and significantly enhancing discharge duration. This controlled cooling resulted in up to a 7% improvement in cell discharge capacity for a voltage drop to 80% of the rated capacity. The study demonstrates that discharge performance is critically influenced by temperature non-uniformity, cooling rate, and state of charge. Thermographic imaging at a 1.75C load under natural convection, for instance, revealed significant surface temperature variations of 0.5°C to 6°C within just 10 minutes. This work provides a critical insight for optimizing thermal management strategies to improve battery performance and longevity.
Mane et al. (2026) studied this question.