Ambient Temprature of a battery (under low temp)

Hello,

I am trying to simulate a battery under cold temprature, somewhere around 263.15 K. When I simulate the battery at room temprature it is giving me a desired discharge capacity vs cycle number graph. However, when I try update the paramter "Ambient temperature [K] " to 263.15 there does not seem to be much difference in room temp and cold temp graphs.

I am running this:

pybamm.set_logging_level(“NOTICE”)

Load Chen2020 parameter set

parameter_values = pybamm.ParameterValues(“Chen2020”) #Mohtat2020

parameter_values.update({
‘Initial concentration in negative electrode [mol.m-3]’: 24866.0,
‘Initial concentration in positive electrode [mol.m-3]’: 16038.0,
“SEI kinetic rate constant [m.s-1]”: 1e-13,
“Nominal cell capacity [A.h]”: 4.2,
“Lower voltage cut-off [V]”: 2.5,
“Upper voltage cut-off [V]”: 4.2,
})

Load the Single Particle Model (SPM)

spm = pybamm.lithium_ion.SPM({“SEI”: “ec reaction limited”})

Define the experiment

experiment = pybamm.Experiment(
[
(
“Discharge at 1C until 2.5V”,
“Charge at 1C until 4.2V”,
“Hold at 4.2V until 1C”,
)
] * 300,
termination=“80% capacity”,
)

sim = pybamm.Simulation(spm, experiment=experiment, parameter_values=parameter_values)

# Solve the model

sol = sim.solve()

also, I have been reading the source code and documentation and there does not seem to be much information regarding the Ambient temperature of the model. I wanted to ask if the Ambient temperature has been implemented? if not, I would like to get guidance on where should I start if I want to implement such a feature. The most relevant formula I found is the arrhenius equation.

I would greatly appreciate any help.

Hi Guri,

I believe that “Ambient temperature [K]” refers to the temperature of the surrounding environment and is only taken into account in your simulation if you use a thermal model (e.g., “thermal”: “lumped”). If no thermal model is active, this parameter is ignored, and the cell temperature remains fixed at the “Initial temperature [K]”. To simulate at a different temperature, you should adjust the “Initial temperature [K]” parameter, which sets the starting temperature of the battery. If you’re using a thermal model, you might also want to set “Ambient temperature [K]” to define the external conditions affecting heat exchange.

The "Chen2020" parameter set does not have much temperature dependence. Try using "ORegan2022" instead. You may need to add more mesh points in the r direction to get an accurate solution.