Influence of the Cathode Catalyst Layer Void Volume on the Short‐term and Long‐term Performance of PEM Fuel Cell

Abstract

The cathode catalyst layer void volume of the proton exchange membrane fuel cell (PEMFC) determines the available three‐phase regions and routes of mass transfer in the membrane electrode assembly (MEA). In this paper, four MEAs with different void volume of cathode catalyst layer have been made and their performance was evaluated and analyzed. The results show that for the MEA with cathode catalyst layer porosity of 20.8%, an optimal structure and a proper balance between catalyst layer void volume and Nafion content is obtained. The optimal void volume caused that electrochemical surface area for the MEA with the optimal structure be 1.45 times higher than MEA having a porosity of 29.5% at the end of the long‐term cycles. On the other hand, the mass transfer resistance (Rmt) at the end of long‐term cycles for MEA with the optimal structure is 4.8 times less than the same MEA having a porosity of 15.9%. This fact makes that MEA with the cathode catalyst layer porosity of 20.8%, both in short and in the long‐term, has higher and more stable performance than other MEAs; so that its maximum output power density has changed only 0.8% during 200 cycles.

Cathode Design for Proton Exchange Membrane Fuel Cells in Automotive Applications

“…Suzuki et al [93] reported that the ionomer content was the determinative factor of CL void volume. Taghiabadi et al [95] evaluated the performance of different void volumes and found a 20.8% CCL porosity leading to the best MEA performance. Sassin et al [96] examined the interplay between the porosity and thickness of the CCL on its mass transport limitations in PEMFCs.…”