Experimental investigation on scaling and stacking up of proton exchange membrane fuel cells

• Effect of reactant back pressure has profound effect on the performance of PEMFC.
• Scaling up of PEMFC causes decrease in the power density.
• Interdigitated flow channels show superior performance than serpentine flow channels.
• Stacking up of PEMFC results in reduced power density when compared with single cell.
• Cell cooling improves performance for two cell stack for operating temperatures above 60 °C.

The performance of a proton exchange membrane fuel cell (PEMFC) with various flow channel design (serpentine and interdigitated) with different landing to channel ratios (L:C = 1:1; 2:2) for an active area of 25 cm2 and 70 cm2, for single cell and two cells stack is studied and compared. The effect of back pressure on the PEMFC performance is also investigated. This study establishes a strong relation between back pressure and power output from a PEMFC. It was concluded that the interdigitated flow channel gives better results than the serpentine flow channel configuration for various landing to channel ratios. It was also found that power outputs do not proportionally increase with active area of the membrane electrode assembly (MEA). Similarly, stacking up studies with single cell and two cell stack shows that the two cell stack has reduced power densities when compared to that of a single cell. The effect of cooling channels with natural and forced convection by using induced draught fan on the performance of a PEMFC stack is also studied. Fuel distribution and temperature management are found to be the significant factors which determine the performance of a PEMFC stack.