Analysis of electrochemical impedance （电化学阻抗分析）.pdfVIP

INTERNATIONAL JOURNAL OF ENERGY RESEARCH Int. J. Energy Res. 2005; 29:1133–1151 Published online in Wiley InterScience (). DOI: 10.1002/er.1144 Analysis of electrochemical impedance spectroscopy in proton exchange membrane fuel cells Parthasarathy M. Gomadam and John W. Weidnern,y Center for Electrochemical Engineering, Department of Chemical Engineering, University of South Carolina, Columbia, SC 29208, U.S.A. SUMMARY A literature review of electrochemical impedance spectroscopy (EIS) analysis of proton exchange membrane fuel cells (PEMFCs) is presented. Emphasis is placed on the papers that analyse the impedance response of the cathode and anode half-cells of the PEMFCs based on a continuum-mechanics approach. The other type of analysis, which is based on the equivalent-circuits approach, is addressed for comparison. The relative advantages and disadvantages of the two approaches are discussed. Papers dealing with continuum-mechanics-based EIS modelling of general electrochemical systems are briefly reviewed. Copyright # 2005 John Wiley Sons, Ltd. KEY WORDS: impedance; EIS; fuel cell; porous electrode; catalyst layer; Nyquist plot; linear kinetics; Tafel kinetics; equivalent circuit 1. INTRODUCTION A schematic of a proton exchange membrane fuel cell (PEMFC) stack is shown in Figure 1 along with blown-up views of the seven-layer membrane electrode assembly and the catalyst region. The reactant gases, hydrogen and oxygen/air, are flown into the fuel cell through the flow-fields. The flow-fields are normally made of a light, electronically conducting material (e.g. graphite) with channels grooved in them for gas flow. From the flow-fields