Cascaded electrochemical-thermal modeling and temperature estimation for cylindrical Li-ion batteries

Cascaded electrochemical-thermal modeling is essential for understanding the intricate temperature dynamics of lithium-ion batteries, which directly impact their safety, performance, and longevity. This study introduces a comprehensive multi-layer model that captures detailed thermal and electrochemical interactions across all layers and components of a cylindrical lithium-ion battery. While the multi-layer model provides precise temperature distribution and might identify potential hotspots, its complexity makes real-time applications challenging. To address this, a simplified single-layer model is developed, focusing on a single representative layer with eight components. This model reduces computational demands, enabling efficient real-time temperature estimation. Experimental validation demonstrates the superior accuracy of the multi-layer model compared to the single-layer model, which trades detail for simplicity. To bridge the gap between accuracy and practicality, an optimized sensor placement strategy is proposed, supported by a Luenberger observer to estimate battery case temperatures using experimental data. These findings underscore the potential of the proposed models to enhance thermal safety, optimize monitoring, and guide the development of next-generation battery technologies. • Developed and validated a multi-layer model for internal temperature. • Proposed a simplified single-layer model for efficient thermal estimation. • Integrated electrochemical and thermal dynamics to model battery behavior.