Thermal Modeling and Performance Evaluation of Tesla 4680 Lithium-Ion Cell

This study presents an electro-thermal modeling framework for the Tesla 4680 cylindrical lithium-ion cell, aiming to evaluate its performance under various C-rate conditions. A second-order equivalent circuit model (ECM) was developed to simulate the cell’s voltage response, incorporating an open-circuit voltage source, a series resistance, and two RC branches that represent charge-transfer and diffusion polarization phenomena. The ECM was coupled with a lumped thermal model to assess heat generation and dissipation during dynamic operating conditions. The open-circuit voltage was estimated using reconstructed experimental data and fitted via a mixed exponential-polynomial function of the state of charge (SOC), allowing accurate representation across the full SOC range. Parametric dependencies on SOC and temperature were introduced for all electrical components, enabling realistic real-time simulations. Discharge and charge cycles were simulated across a range of C-rates, with a focus on thermal response and energy efficiency. Results demonstrate good agreement with expected electrochemical behavior and highlight the model’s effectiveness in identifying optimal operating conditions. The approach provides a computationally efficient tool suitable for applications such as electric vehicle battery packs and energy storage systems, where thermal management and efficiency are critical.