Lithium plating during calendar aging in pybamm model

PyBaMM Q&A
1

team pybamm,

I am simulating calendar aging in PyBaMM for a cell stored at 95% SOC and 40 °C.

my model setup is as follows,

model = pybamm.lithium_ion.DFN(
{
“cell geometry”: “arbitrary”,
“thermal”: “lumped”,
“SEI”: “solvent-diffusion limited”,
“SEI porosity change”: “true”,

“lithium plating”: “partially reversible”,
“lithium plating porosity change”: “true”, # alias for “SEI porosity change”
“loss of active material”:“stress-driven” ,
“calculate discharge energy”:“true”
},
)

solver = pybamm.IDAKLUSolver()

When lithium plating is enabled in the model, I see a noticeable amount of plated lithium loss. I was expecting plating to be negligible during calendar aging modeling, since there is no applied charging current.

  • Is this expected behavior in PyBaMM, from literature i understand li plating loss to be negligible during storage.

  • Should i switch off plating sub model explicitly for calendar aging modeling (in the pybamm git-hub calendar aging example problem only SEI sub model is activated)

thanks and regards

Thiyaga

2

Hi Thiyaga,

During calender aging it is recommended only to use these options:

“SEI”: “solvent-diffusion limited”,
“SEI porosity change”: “true”

and turn of all other options such as Lithium plating, LAM, or cracking. I noticed that with these other options in the model, there is quite a lot of unrealistic capacity lost in other mechanisms like cracking which should not really happen in calendar aging when there is no current.

Hope this helps,

Priya

3

Hi @priya6ik ,

thanks for the kind note. yes, activating only SEI helps.

Thiyaga