Projection of charge and discharge curves at constant current by impedancespectroscopy

A method to calculate charge and discharge curves of an electrochemical cel l from the impedance data is described, and its validity is examined by mea suring an impedance together with charge and discharge curves of a lithium cell with a high-area carbon electrode. The capacity to store and deliver e lectricity and the polarization voltage were well illustrated from the impe dance spectroscopic data via a computational transformation. Since a method is a reversible conversion from a frequency domain to a time domain by the Fourier transform, impedance spectroscopic data are also obtained from the steady-state charge and discharge curves. A significance of introducing th is complemental method to impedance measurements of the electrochemical cel ls especially in frequencies from mu Hz to 1 Hz is described.