An electrochemical impedance spectroscopy method applied to porous LiMn2O4 and metal hydride battery electrodes

An electrochemical impedance spectroscopy method utilizing the signals from reference electrodes positioned in front of and behind a porous electrode is investigated. The basis for the method is illustrated theoretically, and limiting values under different assumptions are presented. The method was applied to a porous metal hydride and a LiMn2O4 battery electrode. It was concluded that the method facilitates the separation of local impedance effects from the effects of the potential distribution in the porous electrode. Consequently, a more accurate determination of local kinetic parameters and the effective conductivity in the pore electrolyte could be obtained. (C) 2003 The Electrochemical Society.