diffthermo is a python library for fitting thermodynamically consistent OCV models. It takes OCV and SoC as input, automatically does all the fitting and returns OCV models in PyBaMM and Matlab formats.

Install the environment first

conda create -n diffthermo python=3.11  torch=2.0.0 numpy=1.24 matplotlib pandas

After succesfully installed the environment,

conda activate diffthermo 

and then copy the diffthermo folder into your work directory.

It's as simple as only 3 lines of commands!

from diffthermo.utils import train, write_ocv_functions
# fit the OCV function
params_list = train(datafile_name='data.csv', 
                    number_of_Omegas = 6, 
                    learning_rate = 1000.0, 
                    total_training_epochs = 8000,
                    loss_threshold = 0.01)
# write the fitted OCV function in PyBaMM OCV function format
write_ocv_functions(params_list)

After the fitting, you can find your fitted PyBaMM OCV function in the file fitted_ocv_functions.py, and the MATLAB OCV function in the file fitted_ocv_functions.m. Copy and paste them into your own projects and that's it! Incredibly easy, isn't it?

See examples for the files. If you want to learn more on the method, please refer to the paper "Open-Circuit Voltage Models Should Be Thermodynamically Consistent", https://pubs.acs.org/doi/10.1021/acs.jpclett.3c03129

diffthermo: the source code.

examples: example on how to fit a thermodynamically consistent OCV functions with a graphite OCV dataset.

data_for_manuscripts: contains all source code & run results for the paper "Open-Circuit Voltage Models Should Be Thermodynamically Consistent".

pybamm_OCV_functions: contains all the 12 fitted thermodynamically consistent OCV functions, implemented in PyBamm. You can get your OCV model in Matlab by running the fitting process and check the output file fitted_ocv_functions.m.

If you find this repo useful in your research, please cite this work as follows (BibTex Format):

@article{doi:10.1021/acs.jpclett.3c03129,
author = {Yao, Archie Mingze and Viswanathan, Venkatasubramanian},
title = {Open-Circuit Voltage Models Should Be Thermodynamically Consistent},
journal = {The Journal of Physical Chemistry Letters},
volume = {0},
number = {0},
pages = {1143-1151},
year = {0},
doi = {10.1021/acs.jpclett.3c03129},
URL = { 
        https://doi.org/10.1021/acs.jpclett.3c03129
},
eprint = { 
        https://doi.org/10.1021/acs.jpclett.3c03129
}
}