Running Aging cycles with Okane parameter set

[Dhawal-Goyal]

Hello I am running a aging cycles using Okane parameter set with SEI, lithium plating and LAM options enabled as follows:

options = {"SEI": "ec reaction limited","lithium plating": "partially reversible", "loss of active material": "stress and reaction-driven"}
dfn = pybamm.lithium_ion.DFN(options = options)
params = pybamm.ParameterValues('OKane2022')

the experiments has been set up as below:

drive_cycle_current = pd.read_csv("US06.csv", comment="#", header=None).to_numpy()

experiment3 = pybamm.Experiment([
("Charge at 1C until 4.2V",
"Hold at 4.2V until C/50",
"Discharge at 1 C for 7 minutes",
"Run US06_A (A) for 3 hours",
"Discharge at 0.2C until 2.7 V")
] * 20,
drive_cycles={ "US06_A": drive_cycle_current,},
termination="80% capacity",
)

US06 drive cycle has been taken from the pybamm input folder.
While the simulation ran, the cell is degrading extremely fast (lost 10% capacity in 16 cycles itself). Also, the voltage fluctuations are becoming bigger every cycle. I am not sure i understand why this is happening. May be my current values are too large for the cell. But how do I create a more appropriate profile. Some guidance would be helpful.

I have attached the images of the plots.

[RuiheLi]

Hi~

I think the OKane2022 parameter relates to a paper which uses solvent-diffusion limited SEI. Therefore, it is likely that you get very quick degradation when switching to ec reaction limited SEI. According to the source code here, there are two ageing paramters that control the degradation rate of this ec reaction limited, k_sei (k_sei ) and D_ec (EC diffusivity [m2.s-1]). You can start from changing these values. Also if you have turned on lithium plating and LAM, there are more ageing parameters to tune, such as "Dead lithium decay constant [s-1]", 'Lithium plating kinetic rate constant [m.s-1]', "Negative electrode LAM constant proportional term [s-1]".