Modification of the liquid cooling channel of PEMFCs for their operation with dry reactant gases

In order to tackle both water and thermal problems, a modified PEMFC is proposed in the present study for its operation with dry reactant gases via the modification of liquid cooling channel with circulating liquid electrolyte. Fuel cell with both circulating liquid electrolyte and solid polymer membrane operated with either dry or humidified H2/O2 is compared in the present study at temperatures of 40, 50, 65, and 80 °C, respectively. The measured E–I data show that such single cell can be operated at 80 °C without humidification.Besides, a semi-empirical equation to predict the current/voltage relationship, and the electrochemical impedance method are also employed in the present study for cell resistance analysis. The analysis results show that the high interfacial resistance should be one of the major reasons for the inferior performance of the present cell. Based on the discovery, an improvement of the present fuel cell is further proposed by Nafion ionomer spreading on the electrode before the assembly of membrane and electrode. The maximum power density of the cell after electrode treatment reaches 75 mW/cm2 for dry H2/O2 operation at 0.4 V, which is almost threefold improvement compared with that without electrode treatment.