A one-dimensional numerical model of carbon corrosion in catalyst layers of proton exchange membrane fuel cells

Abstract

Understanding interaction between carbon corrosion and physicochemical processes inside proton exchange membrane fuel cells (PEMFCs) is important. A one-dimensional carbon corrosion model considering cathode catalyst layer (CCL) structure evolutions is established and coupled with one-dimensional PEMFC performance model. The coupled model is validated and employed to predict CCL structure evolution and PEMFC performance degradation during accelerated stress test. The results find that high relative humidity can enhance performance but accelerate carbon corrosion. Increasing carbon loading and decreasing ionomer weight can improve both performance and durability. Low Pt loading leads to reduced performance and durability. There exists an optimal carbon diameter leading to the best performance. Small carbon diameter can enhance cell durability. Proper gradient CCL design can enhance durability at cost of small initial performance reduction. Finally, an optimized structure is proposed with 21.7 % higher current density at 0.6 V and 5.2 % lower performance loss compared with base case.