Characterization and modeling of the swelling behavior of a LiFePO₄ pouch cell in multiple operating conditions

The demand for energy-efficient, eco-friendly solutions has boosted the interest in batteries as a compact energy storage option. Lithium-ion batteries, despite their long lifespan and high energy density, face safety concerns due to operational hazards like cell swelling induced by charge-discharge cycles. This study investigates cell swelling in lithium-ion cells under various conditions and develops a predictive model. Testing two LiFePO4 cells across pressure and temperature variations, the study analyzes the mechanical swelling behavior of the cell and its electrical behavior (impact on DC resistance and capacity) influenced by operational conditions. The modeling section includes a mathematical model for swelling forecast, validated with experimental data, showcasing high predictive accuracy.