Lithium-Ion Cell Simulation

Link to Streamlit App with an integrated PyTorch LSTM model.

There is also a Jupyter Notebook that uses the self-updating ProgressPlot from JupyterPlot:
simulate_cell.ipynb

Uses a 2nd Order RC Model of the ECM in order to simulate voltage and soc behaviour of a lithium-ion cell
subjected to different current profiles.

ECM

$2^{nd}$ order:

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

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

$$ \tau_1 = R_1C_1 $$

$$ \tau_2 = R_2C_2 $$

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

Where:

• $R_0$ is the internal resistance of the lithium-ion cell
• $R_i$ is the resistance of the resistor in the $i^{th}$ RC pair
• $C_i$ is the capacitance of the capacitor in the $i^{th}$ RC pair
• $\tau_i$ is the time constant of the $i^{th}$ resistor-capacitor (RC) pair
• $U_{i,k}$ is the polarization voltage, at time $t = k$ of the $i^{th}$ RC pair
• $V_k$ is the lithium-ion cell's voltage at time $t = k$
• $I_k$ is the current flowing into or from the cell at time $t = k$
• $\Delta t$ is the time interval between times $t = k+1$ and $t = k$