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

Abstract

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 ( R mt ) 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.

Key findings

• ▸MEA with cathode catalyst layer porosity of 20.8% had 1.45 times higher electrochemical surface area than MEA with porosity of 29.5% at the end of long-term cycles.
• ▸MEA with optimal structure had 4.8 times less mass transfer resistance at the end of long-term cycles compared to MEA with porosity of 15.9%.
• ▸MEA with cathode catalyst layer porosity of 20.8% had higher and more stable performance in both short and long-term cycles.

Keywords

Identifiers

DOI

10.1002/fuce.201800023

Journal

Fuel Cells

Year

2018