Fig. 4(a) shows that the output voltage is higher than at other temperatures when the dead-ended cell operated at 50 °C. The cell voltage value increased by 0.03 V, 0.02 V, and 0.06 V (10 %, 6.45 %, 22.22 %), compared to operation at other cell temperature conditions (without cooling, 40 °C, 60 °C). Moreover, the current density distribution value of variance decreased by 14.0 %, 9.8 %, and 40.6 %, respectively, as shown in Fig. 4(b). When the temperature is too low, the catalyst activity decreases, resulting in a drop in output voltage. In addition, too high temperature in dead-ended PEMFC to increase sharply increased the concentration of water vapour, further aggravating the concentration polarization phenomenon and increasing the uneven current density distribution. Therefore, the dead-ended PEMFC output voltage and the uniformity of current distribution are the best obtained at 50 °C. The stack performance presented in Fig. 4(a) is not satisfying. There are two possible reasons for the stack’s poor performance. The first reason may be due to the PCB board used in the measurement, which may be because part of the runner gold plating layer on the board is missing due to wear and tear, resulting in too much resistance of the stack, leading to a decrease in the voltage of the stack. The second reason may be that the MEA has been used for an extended period, which led to a decrease in the rate of electrochemical reaction and, therefore a decrease in the performance. We will ensure the stack performance is within reasonable range in future experiments.
