Electrochemical impedance spectroscopy in PEM fuel cells

This chapter provides a brief discussion about the application of electrochemical impedance spectroscopy (EIS) in polymer electrolyte membrane (PEM) fuel cells. The representation of the impedance response of the PEM fuel cell on the Nyquist and Bode plots is discussed. The instrumentation required to measure and separate the cathodic impedance response from the overall impedance response of the PEM fuel cell is presented. The effect of the inductance from the measurement system on the impedance response of the PEM fuel cell which can mislead the interpretation of the electrochemical phenomena of the PEM fuel cell at high frequencies is discussed as well. This chapter also provides an insight into the change of the impedance spectrum characteristics during EIS measurements carried out in PEM fuel cells under different operating conditions. This chapter also provides a further understanding of ambiguities during the interpretation of the electrochemical impedance spectrum of the PEM fuel cell.