Experimental study on liquid water formation characteristics in a novel transparent proton exchange membrane fuel cell

Abstract

Water management is critical to the operation of a proton exchange membrane fuel cell (PEMFC). The accumulation of water in the cathode channel of a newly designed transparent PEMFC is investigated in this work. The electric quantity per square metre (qe) produced by electrochemical reaction is used to estimate the liquid water formation characteristics. Results show that the water produced by the electrochemical reaction first exists in a gaseous state in the flow channel and then transforms to liquid water.Liquid water begins to appear in the flow channel when qe reaches approximately 1.8 × 105 C·m−2 in different current density and loading rate. However, a higher current density and loading rate would decrease liquid water forming time of the fuel cell channel. In addition, cell temperature affects the qe value, and when the cell temperature rises from 45 to 75 °C, qe decreases from 2.25 × 105 to 1.5 × 105 C·m−2; the amount of charge is approximately inversely proportional to the cell temperature. Liquid water first appears at the inlet of the flow channel, specifically at the contact point between the inlet flow channel and carbon paper. Liquid water is concentrated at the edge channel of the flow field area and rarely distributed in the middle of the single cell.