Performance of proton exchange membrane fuel cells with microporous layer hydrophobized by polyphenylene sulfide at conventional temperature and cold start

Abstract

Polyphenylene sulfide (PPS), a thermoplastic polymer with excellent chemical and thermal stability, has properties similar to those of polytetrafluoroethylene (PTFE) but is less expensive. In this study, the feasibility of using PPS to replace conventional PTFE as a hydrophobic agent for microporous layers (MPLs) in proton exchange membrane fuel cells (PEMFCs) is explored. First, PTFE-MPL and PPS-MPL with 30 wt% hydrophobic agent were prepared. The pore size, porosity, contact angle, and microstructure of the two MPL samples were measured and analyzed. Subsequently, PEMFCs with the two MPL samples were tested for their operational performance at a conventional temperature of 70 °C and cold-start capability at −10 °C. The performances of PTFE-MPL and PPS-MPL at conventional temperatures were similar, but PPS-MPL showed obvious advantages in cold-start performance. In addition, the operating performance of PEMFC at the conventional temperature and cold-start capability at −10 °C were investigated for PPS mass fractions of 10%, 20%, and 30% in MPL, and for PPS particle sizes of 10 and 30 μm. The results indicate that the optimal performance can be attained when the PPS particle size is 10 μm and the mass fraction is 20%.