Quantifying imbalances in parallel-connected cell groups using group voltage and current

This simulated data was produced to investigate the impact of cell-to-cell imbalances on the voltage and current dynamics of a group of parallel-connected cells. From this simulated data, we show that features of the group’s differential voltage with respect to differential state of charge (dV/dz) can quantify imbalance in the capacity-resistance product (CR). We demonstrate that CR imbalance is proportional to imbalances in C-rate and SOC, and that dV/dz features can consequently quantify these imbalances. We develop a novel algorithm, OCP-informed Feature Identification, that accurately and precisely estimates these features from noisy voltage data to enable a robust assessment of imbalances in parallel-connected cell groups.