Low Rate Galvanostatic Charge

Characterization Tool

Measurement of the open circuit voltage profile is the primary output of this electrochemical testing method. By reducing the current to a minimum, the voltage drop across the internal resistance of the cell is practically eliminated. This allows researchers to clearly identify the individual voltage plateaus associated with the phase transitions of the electrode materials, such as the staging transitions in graphite.

This high resolution data is used to validate theoretical models and optimize the composition of the active materials.

Capacity Verification

Precise determination of the total list of active lithium ions within the cell is achieved through this slow charging process. At high charge rates, some of the active material may not be fully utilized due to diffusion limitations, resulting in a lower measured capacity. The slow rate ensures that all available active sites are accessed, providing an accurate measure of the true electrochemical capacity of the cell.

This baseline capacity is used to calibrate the battery management system and track the degradation of the cell over its lifetime.

Industrial Testing

Quality assurance protocols in battery manufacturing often include this test to verify the consistency of the produced cells. Discrepancies in the measured capacity at low rates can indicate manufacturing defects, such as incorrect mass loading of the electrodes or poor electrolyte distribution. While this test requires more time than rapid evaluation methods, it provides the most reliable data for qualifying new cell designs and verifying the performance of the manufacturing line.

The information gained from this test is critical for ensuring the long term reliability of the cells.