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Modeling and Simulation of Heat of Mixing in Lithium Ion Batteries
In this study, a mathematical model was built to simulate heat generation of LIBs using COMSOL Multiphysics. The LIB model was based on Newman’s model. LiCoO2 was applied as the cathode materials, and LiC6 was applied as the anode material. The results of heat of mixing were compared with the other heat sources to investigate the weight of heat of mixing in the total heat generation. Table 1 shows the heat of mixing, irreversible heat, and reversible heat in anode and cathode electrodes at 5 min during a 2 C discharge process. As shown in Table 1, the heat of mixing in cathode is smaller than the heat of mixing in anode, mainly due to the lower Li ion diffusivity and larger particle size of LiC6. The heat of mixing is not as much as the irreversible heat and reversible heat, but it cannot be neglected for this operating condition. The heat of mixing in different LIB cells and under different operating conditions will be reported.
The mathematical model equation(1):
Show in Image 1.
Acknowledgments: This work was supported by the American Chemical Society Petroleum Research Fund.
Table 1. Comparison of the heat of mixing within active material particles with irreversible and reversible heat sources at 5 min during a 2 C discharge process.
|
Cathode(LiCoO2) |
Anode(LiC6) |
Heat of mixing |
3.92 J/m2 |
293.60 J/ m2 |
Irreversible heat |
460.97 J/m2 |
1354.86 J/m2 |
Reversible heat |
1370 J/m2 |
-813 J/m2 |
References:
1. K. E. Thomas and J. Newman, Journal of the Electrochemical Society, 150, A176 (2003).
2. B. Yan, C. Lim, L. Yin and L. Zhu, Journal of the Electrochemical Society, 159, A1604 (2012).
3. K. Kumaresan, G. Sikha and R. E. White, Journal of the Electrochemical Society, 155, A164 (2008).
4. K. E. Thomas, C. Bogatu and J. Newman, Journal of the Electrochemical Society, 148, A570 (2001).