Rapid Impedance Spectrum Measurements for State-of-Health Assessment of Energy Storage Devices 2012-01-0657
Harmonic Compensated Synchronous Detection (HCSD) is a technique that can be used to measure wideband impedance spectra within seconds based on an input sum-of-sines signal having a frequency spread separated by harmonics. The battery (or other energy storage device) is excited with a sum-of-sines current signal that has a duration of at least one period of the lowest frequency. The voltage response is then captured and synchronously detected at each frequency of interest to determine the impedance spectra. This technique was successfully simulated using a simplified battery model and then verified with commercially available Sanyo lithium-ion cells. Simulations revealed the presence of a start-up transient effect when only one period of the lowest frequency is included in the excitation signal. This transient effect appears to only influence the low-frequency impedance measurements and can be reduced when a longer input signal is used. Furthermore, lithium-ion cell testing has indicated that the transient effect does not seem to impact the charge transfer resistance in the mid-frequency region. The degradation rates for the charge transfer resistance measured from the HCSD technique were very similar to the changes observed from standardized impedance spectroscopy methods. Results from these studies, therefore, indicate that HCSD is a viable, rapid alternative approach to acquiring impedance spectra.
Citation: Christophersen, J., Morrison, J., Morrison, W., and Motloch, C., "Rapid Impedance Spectrum Measurements for State-of-Health Assessment of Energy Storage Devices," SAE Int. J. Passeng. Cars - Electron. Electr. Syst. 5(1):246-256, 2012, https://doi.org/10.4271/2012-01-0657. Download Citation
Jon P. Christophersen, John Morrison, William Morrison, Chester Motloch
Idaho National Laboratory, Montana Tech of Univ of Montana, Qualtech Systems Inc, Motloch Consulting, Inc.
SAE 2012 World Congress & Exhibition
Advanced Battery Technology, 2012-SP-2328, SAE International Journal of Passenger Cars - Electronic and Electrical Systems-V121-7EJ, SAE International Journal of Passenger Cars - Electronic and Electrical Systems-V121-7