Magnesium ion pollution effects on electrochemical performance of proton exchange membrane fuel cell

Abstract

The components of proton exchange membrane fuel cell (PEMFC) may degrade and produce metal ions during long-term operation. In this paper, the effects of magnesium ion contamination on PEMFC performance are investigated. Electrochemical performance tests of PEMFC are carried out by injecting two concentrations of magnesium ion contamination solutions into the anode hydrogen stream and the cathode air stream of PEMFC, respectively. And electrochemical impedance spectroscopy (EIS) is used to study the degradation mechanism of PEMFC contaminated by magnesium ion. The results show that the concentration and the pollution time of magnesium ion pollution have important effects on the electrochemical performance of PEMFC. The maximum power density and voltage of PEMFC decrease with the increase of pollution time and magnesium ion concentration. The results of electrochemical performance tests show that magnesium ion contamination can affect the electrochemical reaction kinetics of PEMFC. The research results also show that the damage to the electrochemical performance of PEMFC caused by anode magnesium ion pollutant is more serious than that caused by cathode magnesium ion pollutant. And EIS results indicate that both cathode magnesium ion contaminant and anode magnesium ion contaminant make the ohmic resistance and cathode Faraday resistance increase with the increase of pollution time and magnesium ion concentration.