Temperature dependent battery degradation

[zafar594]

I wanted to analyze battery degradation due to variation in ambient temperatures, is there a degradation model that takes into account temperature? If yes, then which option(s) should I choose to make this degradation function?

[abhishek-appana]

It depends on which degradation model you would like to implement!

For example, SEI degradation submodel (File name: sei_growth.py) takes into account the temperature variation. You can select one of the following SEI options for this:

• "reaction limited"
• "interstitial-diffusion limited"
• "ec reaction limited"

[zafar594]

Thanks for answering! Do you know where I can read more about these SEI options, to decide which one to select under what conditions, for example?

[abhishek-appana]

PyBaMM has all the documentation for SEI on this webpage. You can read the reference papers for further understanding!

The other option is to go through the code. The codes for all the SEI models are here.

[zafar594]

Thank you!

[zafar594]

In my case I have a numpy array for temperature values which I am trying to use as ambient temperature, updated at every time step. I am using this for reference ambi_temp but in my case, instead of a function of time, temperature is simply an array. I tried to modify the input like this (temps is an array for temperature values and duration is length of experiment):

def amb_temp(y, z, t):
    for t in range(duration):
        return temp[t]

but it only takes the first value (temp[0]) for all data points. Otherwise, defining it like this:

def amb_temp(y, z, t):
    return temp[t]

doesn't work at all. What am I doing wrong? Please help!

[Sunnyturicum]

Hi
Not sure which cell you are using for your analysis. But I have done some temperature related work with Pybamm here: https://github.com/ArnaudOlt/dissertation_pybamm
Maybe it helps.