Optimal design of cathode flow channel for air-cooled PEMFC with open cathode

Abstract

Air-cooled open-cathode low temperature proton exchange membrane fuel cell (AO-LTPEMFC) with low weight, small volume and compact system has become the new potential power source in the unmanned aerial vehicle (UAV). However, the desirable parameters of the cathode channel are a very important factor to influence the cell performance and the compact of the stack, which have the higher requirements put forward to the structural designs of the cathode channel of AO-LTPEMFC. Thus, some single AO-LTPEMFC fabricated with different width:0.9–1.5 mm, depth:1.1–1.5 mm, ratio (width/landing):1:0.7–1:1.3 and bending:0–10° of the cathode channel was investigated to optimize the cell performance and temperature distribution in the 2 mm plate and determine desirable design parameters. The results show that the different design parameters of the cathode channel affect the contact resistance, oxygen mass transfer of cathode and pressure drop in air flow. For AO-LTPEMFC, to keep the best performance, the cathode channel design parameters should be operated at appropriate width, as deep as possible, small ratio and bending. Through the comparison of various designs, combined with practice process, the optimum design size with width (1.1 mm) × depth (1.3 mm) × width/landing (1:0.7) × bending angel (θ) (5°) was obtained based on the 2 mm thickness of the bipolar plate, which could get the maximum performance and improve the compactness of system. Moreover, analysis in this study will provide a new guideline for the development of cathode flow field plate design in application.