Detailed characterization and parameterization of a large state-of-the-art commercial Li-ion pouch cell. Part 1: Cell characterization

Description

Methods (En)

All characterization and cycling of the full cell were performed with battery testers from PEC (SBT-0550 or ACT-0550), within the voltage limits of 3 V to 4.2 V (as specified by the manufacturer). During testing, the cells were kept in temperature-controlled environments. The surface temperature of all cells was monitored using a Pt-100 temperature sensor that was mounted at the top center of the pouch cell surface. The applied currents during testing are specified as C-rates, i.e., the actual current divided by the cell’s nominal capacity of 64 Ah. All charge steps were finished with a constant voltage-hold step until the current dropped below 0.05C.

Electrochemical impedance spectroscopy (EIS) data was collected using a Zahner Zennium Pro potentiostat. During data collection, the cells were placed in a high-precision temperature-controlled environment and allowed to equilibrate at the selected temperatures for at least 6 hours. EIS data was collected within a frequency range from 1 kHz to 20 mHz, and an AC amplitude of 2 A. A lower amplitude of 1 A was used for the low temperature measurements (0 and 5°C).