Numerical and experimental investigation of the thermal and electrical characteristics of a lithium ion cell

• Published in: E3S web of conferences Vol. 321; p. 3007
• Main Authors: Özdemir, Tanılay, Ekici, Özgür, Köksal, Murat
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Les Ulis EDP Sciences 2021
• Subjects: Charge transfer; Discharge; Electric cells; Electric potential; Electrochemistry; Electrodes; Liquid phases; Lithium; Lithium-ion batteries; Solid phases; Surface temperature; Temperature gradients; Thermal analysis; Three dimensional models; Variation; Voltage
• ISSN: 2267-1242; 2555-0403; 2267-1242
• DOI: 10.1051/e3sconf/202132103007

In this study, an electrochemical-thermal coupled model was developed to investigate the electrical and thermal behaviors of the commercial NCR18650b Li-ion cell during three different discharge rates. The 1-dimensional electrochemical model consists of a positive electrode, electrolyte, and a negative electrode and employs the related mass and charge transfer equations for both solid and liquid phases predicting the cell's voltage variation. The 3-dimensional thermal model involves a mandrel, an active battery part, and a shell. The thermal model solves the general heat diffusion equation and predicts the temperature variation of the cell. The results show that the predicted temperature-voltage profiles follow the same trend with experimental data and are consistent. The maximum calculated root mean square errors are obtained as 0.11 V for voltage, and 0.96 °C for temperature predictions. On the other hand, the maximum temperature differences within the cell was found to be 0.16 °C, 0.43 °C, and 1.29 °C after the 0.5 C, 1C and 1.5 C rate discharging processes, respectively. Finally, the results from the 3-dimensional thermal model reveal that the type of mandrel affects the temperature variation within the cell. However, the average surface temperature of the cell remains comparable for the investigated C rates.