/lithium_ion_ecm_fit

LFP cell ECM parameterization using second order RC model.

Primary LanguagePython

LFP Cell HPPC Parameterization

This repository is based on the Battery-HPPC-model-fitting repo by Manh Kien Tran, Chemical Engineering PhD Candidate at the University of Waterloo
The data used to develop both these repositories was the same and can be found in his repo. His model is in MatLab, mine is in Python.

The HPPC test is characterized using the second order RC model of the ecm.
scipy.curvefit() parameterizes the ecm function and the resulting modeled and experimental voltage are plotted using Plotly by the end of the parameterization

EDIT Dec 2022: Will consider adding a feed forward neural network and a custom loss function script that will parameterize the 2nd order ECM using machine learning

ECM

$$ U_{1,k+1} = exp(-\Delta t/\tau_1)\cdot U_{1,k} + R_1[1 - exp(-\Delta t/\tau_1)]\cdot I_k $$

$$ U_{2,k+1} = exp(-\Delta t/\tau_2)\cdot U_{2,k} + R_2[1 - exp(-\Delta t/\tau_2)]\cdot I_k $$

$$ \tau_1 = R_1C_1 $$

$$ \tau_2 = R_2C_2 $$

$$ V_k = OCV - R_0I_k - \sum_{i=1}^{2}U_{i,k} $$