Thermally Corrected Degradation Mode Quantification in Lithium Cells
Thermally corrected degradation mode quantification decouples kinetic impedance masking from true lithium inventory loss to prevent false warranty claims.
Thermal Correction Factor
Meaning
Adjustment parameters for electrochemical measurements normalize data collected at varying temperatures to a standard reference value (usually twenty five degrees Celsius). The thermal correction factor accounts for the changes in ion mobility and internal resistance that occur as the cell warms or cools. Applying this factor allows for the comparison of battery performance across different test environments.
Capacity Calibration
Available energy from a cell decreases in cold conditions because the internal resistance prevents full discharge at a given voltage cutoff. A thermal correction factor is used to estimate what the capacity would be under ideal conditions. This ensures that a battery is not incorrectly flagged as faulty during winter operation.
Voltage Accuracy
Open circuit voltage varies slightly with temperature due to the entropy change of the electrochemical reaction. Without a thermal correction factor, state of charge estimation based on voltage would fluctuate as the battery pack heats up during use. The correction ensures the dashboard display remains stable.
Power Estimation
Maximum pulse power capability is highly dependent on the current temperature of the electrolyte. Control algorithms use the thermal correction factor to set safe operating limits that prevent the cell from reaching the lithium plating potential. This adjustment protects the battery from damage while maximizing the available performance.