Comparison between the impedance spectra of Li/SOCl2 batteries obtained using the time and the frequency domain measurement techniques

A comparison between the impedance spectra of Li/SOCl2 batteries obtained in the time and frequency domains is reported. It is demonstrated that by averaging over several responses the accuracy in the time domain is greatly improved. On the other hand, it was found that the time domain technique caused nonlinearity in the system response even at very small amplitudes of excitation (for example corresponding to a potential drop of 30 mV). The method is useful for routine characterization of the quality of galvanic cells in industrial production. The accuracy compared with market-available impedance spectrometers operating in the frequency domain is satisfactory (±10%), the price being much lower.