Equivalent Circuit Modeling of Sodium-Ion Batteries Incorporating Temperature Effects: A Comprehensive Investigation

The shift from internal combustion engine vehicles to electric vehicles has driven significant advancements in battery technology, aiming for safer and more reliable energy storage solutions. While Lithium Iron Phosphate (LFP) batteries are known for their safety, they are dependent on critical elements such as copper, lithium, and graphite. The safe transport of Li-ion batteries remains a concern. Addressing these challenges, Sodium Ion Batteries (SIBs) have emerged as sustainable alternatives suitable for lightweight electric vehicles (EVs). Ensuring their seamless integration into EV battery packs requires preparedness for the rapid evolution of SIB technology. Model-based approaches, including Equivalent Circuit Models (ECMs), play a pivotal role in developing advanced Battery Management Systems (BMS) and State of Charge (SoC) estimation algorithms for precise battery control. This study conducts a comprehensive evaluation using various order resistance-capacitance (RC) ECM configurations, assessing SIB through Hybrid Pulse Power Characterization (HPPC) at discharge rates of 0.5C, 1C, and 1.5C at 25°C. ECM with different model parameters are examined for Mean Absolute Error (MAE) and Root Mean Square Error (RMSE) to determine optimal HPPC test profiles and ECM configurations. With insights from the metrics, the model is expanded to include temperatures from -20°C to 55°C, ensuring enhanced performance across varied environmental conditions. Subsequent validation against the Modified Indian Drive Cycle (MIDC) and World Harmonized Light Vehicle Test Procedure (WLTP) ensures accuracy across diverse real-world driving scenarios. These insights contribute to the development of efficient and dependable SIB-based EV battery packs, supporting the sustainable advancement of electric mobility.