Hi, Everyone
I am currently trying to reproduce the transient response behavior during low-temperature discharge using the DFN model.
However, even after adjusting the thermal conductivity and heat capacity parameters, I was unable to reproduce the voltage recovery due to self-heating after the voltage drop during the initial discharge phase.
Is a lumped model better for simulating heat buildup inside a battery? Or is there another suitable temperature model? Please advise.
To ignore the effect of self-heating, you can use the isothermal model in PyBaMM. However, if your work requires an accurate prediction of heat generation and temperature evolution, it is important not to neglect contributions from the different heat sources, such as ohmic heating, irreversible electrochemical heating, reversible (entropic) heating, heat of mixing, hysteresis electrochemical heating, and current collector heating. Accounting for these effects generally improves thermal model fidelity but also requires a larger and more detailed set of parameters compared to simplified thermal models.
In addition, the transient response is strongly influenced by diffusion resistances, so adjusting particle diffusivities and particle radii can also play an important role in capturing the correct dynamics.
If this does not fully address your question, I would suggest sharing the relevant portion of the code so that we can run it and provide more targeted feedback.
Thank you for the thoughtful response to my question. However, my question was intended for the opposite purpose. Sorry for the confusing questions.
To reproduce the voltage re-rising after the initial drop during discharge in low-temperature and high-load current conditions, I aim to obtain simulation results where the self-heating causes the central battery temperature to become higher than the cell surface temperature. In this case, can I create a thermal model similar to the actual battery?
The X-Full models could not reproduce the large temperature difference between the surface and center of the cell with correct parameters because they were designed to simulate the temperature model for an extremely small area of the electrode.
If you know of a good model that reproduces the temperature at the center and surface of the cell, please let me know.