Experimental and Numerical Investigations of Thermal Characteristics and Cooling Performance of Sodium-Ion Batteries

Sodium-ion batteries (SIBs), owing to their cost-effectiveness and outstanding thermal safety, show great promise for energy storage applications, which is essential for improving the comprehensive utilization of renewable energy and advancing sustainable energy development. However, the thermal management technologies for SIBs have failed to attract enough attention for further research. Herein, temperature rise experiments of SIBs were carried out to explore their heat generation and transfer characteristics. The voltage and temperature rise characteristics, internal resistance, and entropy heat coefficient were investigated under various environmental temperatures and charge/discharge rates. Based on these findings, a thermal model was established according to the Bernardi theory. This model accurately describes the thermal behavior during the discharging process, enabling the prediction of heat generation in SIBs. The optimal air-cooled structure and operating condition parameters for the SIB pack were obtained using an orthogonal numerical optimization design. After optimization, the maximum temperature of the single cell is reduced by 7.76 °C, which is followed by a decrease of 21.33%. The average temperature difference of the SIB pack is 0.97 °C, which is reduced by 73.30%. This research is conducive to effectively controlling battery temperature within an optimal range to prevent combustion, explosion, and other thermal runaway events, providing a certain support for thermal management design for SIB packs in practical applications.