Experimental study on internal temperature dynamics of a modified reversible <scp>PEM</scp> fuel cell with in situ hydrogen adsorption capability

Abstract The present experimental study provides an insight into temperature variations observed on both the oxygen and hydrogen side bipolar end plates of a modified reversible polymer electrolyte membrane (MRPEM) fuel cell. A single cell with an active area of 2.5 cm × 2.5 cm, with an integrated activated carbon electrode for hydrogen adsorption, is utilized for testing. To ensure smooth reactant distribution over the active area and to facilitate easy gas expulsion during operation, a parallel flow field with a depth of 0.1 cm was implemented on the bipolar end plates of the cell. The experimental findings demonstrate that the hydrogen side of the developed cell has a maximum operating temperature of 74°C during electrolyzer (E)‐mode operation, while the oxygen side displayed a maximum temperature of 26°C at 5 V, respectively. During E‐mode operation, the developed cell achieved its gravimetric hydrogen storage density of 0.99 wt.% (weight percent). The electric performance of the developed device is assessed by connecting it to an electronic load under normal temperature pressure (NTP) conditions in a fuel cell (FC)‐mode operation. In the initial discharging phase, the developed cell supplied a peak output voltage of 1.27 V, along with a maximum current of 0.37 mA. The experimental results show that variations in cell operating temperature necessitate further research on the cooling of reversible PEM fuel cells to enhance hydrogen storage capacity, thereby making them technically viable for stationary and portable applications.