Comparative Investigation of Polyphenylene Sulfide Polymer-Graphite Bipolar Plates for Fuel Cell Application

Abstract

In this work two compression molded commercial polyphenylene sulfide (PPS) polymer-graphite composite bipolar plates (BPPs) with 15 and 20 % of polymer binder material from two different manufacturers were employed for an analytical comparative investigation using physical and electrochemical analysis. Chemical stability of BPPs was investigated after storage in phosphoric acid. Corrosion resistance and electrochemical aging of the BPPs were studied by using linear sweep voltammetry, cyclic voltammetry and electrochemical impedance spectroscopy in phosphoric acid. In order to characterize the difference in physical properties water contact angle measurement and through-plane electrical conductivity experiments were performed. Comparison of BPPs revealed that the surface roughness and electrical conductivity is ca. 40 % lower while acid uptake and hydrophilicity is ca. 35 % higher for BPP with higher amount of PPS. Moreover, there was a trend of corrosion rate reducing for BPP with increased PPS content. This behaviour could be explained based on structure and electrical properties of the materials.

Investigation of Corrosion Methods for Bipolar Plates for High Temperature Polymer Electrolyte Membrane Fuel Cell Application

“…For set-up A, it can be observed that the pristine sample has a rather smooth surface with rms of 824 nm in comparison with the aged with rms of 1114 nm, which shows randomly distributed dents within the composite structure ( Figure 4). Comparable roughness values with graphite composite-based bipolar plates were reported in the literature [31,32]. Analogously, detectable differences can be determined for set-up B, while the pristine samples also show a more homogeneous surface with rms of 897 nm before aging and 1628 nm after the procedure.…”

“…It can be concluded that the surface morphology and structure of BPP are closely related to the corrosion behaviour in both set-ups and can be distinguished using SEM and confocal microscopy. The dependency of roughness values and the corrosion current is also shown by Dushina et al, where similar polymer graphite BPPs were investigated in terms of electrochemical aging, and surface roughness equal to 967 nm was reported [31]. The results generated by two different corrosion cells demonstrated the importance of the set-up and the arrangement of electrodes for research on corrosion behaviour.…”

Carbon Material-Reinforced Polymer Composites for Bipolar Plates in Polymer Electrolyte Membrane Fuel Cells

“…Polyphenylene sulfide (PPS) has excellent chemical resistance, low degradation at high temperatures, and high rigidity. It also shows remarkable fatigue endurance and creep resistance, which have attracted extensive attention to it regarding its use for BPs [ 72 , 73 , 74 ]. However, PPS has a low elongation to break and low conductivity [ 75 , 76 ].…”