Hi all,
I am runing an aging model in pybamm considering various side reactions. I thought the following model setting, i.e.,
model = pybamm.lithium_ion.DFN(
{
“SEI”: “none”,
“SEI porosity change”: “false”,
“lithium plating”: “none”,
“lithium plating porosity change”: “false”,
“particle mechanics”: (“none”, “none”),
“SEI on cracks”: “false”,
“loss of active material”: “none”,
}
)
would return exactly same solution with just using model= pybamm.lithium_ion.DFN(). However, they returned different results under same operations, the terminal volatge shows like this:
Is there any possible reason for this difference? I am wondering maybe there are some default side reaction model runing under the first model setting, is that true?
Thank you very much for your time!
Which parameter set are you using? (If you don’t specity one, the default is Marquis2019.)
Thank you so much for the reply, Dr. O’Kane! I am using OKane2022 param set now.
Also, about the submodels, if I choose “SEI”: “solvent-diffusion limited”, “particle mechanics”: (“swelling and cracking”, “swelling and cracking”), and “SEI on cracks”: “true”, does Pybamm actually solve both the Eqn.6 and Eqn.21 in the wonderful paper “Lithium-ion battery degradation: how to model it”? It seems to me that the SEI potential doesn’t rely on the SEI thickness on cracks in the model, is that true?
Thank you again for your generous help!
Sorry for the delay! You asked a lot of questions at once so I wasn’t sure how to answer!
Anyway, I found the reason you are getting an unusual result. It’s a bug in PyBaMM. Normally, PyBaMM has stress-assisted diffusion enabled by default, unless "Particle mechanics" is set to "none", in which case it is switched off. However, you set it to ("none, "none"), which is not the same as "none", and so stress-assisted diffusion is switched on.
Regarding the crack model, my advice is not to use it, for reasons explained in this paper.
