Effect of Gas Impurities on PEFC Performance Determined by Electrochemical Impedance Spectroscopy

Abstract

Effect of gas impurities such as CO, SO₂ and NO₂ on PEFC performance was investigated by electrochemical impedance spectroscopy. In a usual single cell, oxygen partial pressure, temperature and humidity level are different from one position to another position, resulting complexity in accurate analysis of electrochemical impedance. A new single cell of small active area, 1 cm², was utilized to maintain uniform temperature, gas partial pressure and humidity level across the entire single cell. Degree and rate of poisoning by impurity gases were investigated as a function of operating conditions such as cell temperature and humidity level.