Estimating the optimal number of membrane electrode assembly catalyst layers for proton exchange membrane fuel cell by considering open circuit voltage and polarization

This paper reports on a thin polymer membrane with a self-humidifying membrane electrode assembly (MEA) using water generated from the cathode. However, the open circuit voltage was low because the activation and diffusion polarizations were high. Therefore, a multilayered MEA was prepared for a proton exchange membrane fuel cell by the screen-printing method to reduce the two polarizations and improve the open circuit voltage and power density. The MEA consists of a Nafion 115 membrane and a Vulcan XC-72 commercial catalyst (20 wt.% Pt/C) on the anode and cathode. The performances of the multilayered MEA were evaluated for the current–voltage (I–V) characteristics of single cells. In addition, the activation and diffusion polarizations and the open circuit voltage were analyzed for a prepared sample. Excellent characteristics were obtained for the MEA multilayered structure (anode: two layers; cathode: three layers). The activity of both electrodes was increased and a high power density was obtained compared to single-layered MEA.