18650 cell

[akariwrynn]

Hi, I am trying to convert Chen2020 to a 18650 cell by changing the width and height of the electrode. However, when I apply a sinusoidal current, the simulation deletes some points and both current and voltage are not sinusoidal. When I change dt_max, it gives setup failed, calculating jacobian failed, and at the end gives try solving the model up to this time only or reducing dt_max error. I also want to make an coin cell for my experiments but don't know how to do it.

Thanks

[brosaplanella]

That might have to do with the time stepping in the solution, can you share a minimum working example of your code?

[akariwrynn]

I will share it in a moment but I found out that it is working after -5C. At cold, the voltage and current becomes non-sinosodial but rather linear. Do you have any idea about this?

[akariwrynn]

params['Current function [A]']=current
params['Ambient temperature [K]']=temperature+273.15
params["Positive particle radius [m]"]=parameters.get("Positive particle radius")
params["Electrode height [m]"]=0.065
params["Electrode width [m]"]=0.018
solver=pybamm.CasadiSolver("safe")
sim = pybamm.Simulation(model, parameter_values=params,solver=solver)
sim.solve(t_eval=time_array)

current=lambda t: amplitude * pybamm.sin(2 * np.pi * frequency * t)
time_array= np.linspace(0, period/frequency, points_per_period*period)
t_dom_v,t_dom_c=simulation(current, time_array,parameters=parameters,mychemistry=chemistry,temperature=temperature)

Where simulation function contains all the parameters and run the simulation.

As I mentioned above, it works for temperatures above -5C but after that it cuts some points and the output voltage and current are not sin.

Thanks

[brosaplanella]

The code you are sharing does not work in my computer as the simulation function and the parameters are not defined. Can you please share a full example so I can test this on my end?