The Possibility of Intermediate–Temperature (120 °C)–Operated Polymer Electrolyte Fuel Cells using Perfluorosulfonic Acid Polymer Membranes
Katsuyoshi Kakinuma, Hitoshi Taniguchi, Takayuki Asakawa, Toshihiro Miyao, Makoto Uchida, Yasuhito Aoki, Tsuyoshi Akiyama, Akihiro Masuda, Nobuyuki Sato, Akihiro Iiyama
Abstract
The technical possibility and possible issues of an intermediate–temperature–operated polymer electrolyte fuel cell (@120 °C) is investigated with an eye toward the launching of new fuel cell heavy–duty vehicles on the world market. Commercial perfluorosulfonic acid membrane and a commercial Pt catalyst supported on carbon are selected to clarify the possible issues in the fuel cells. The cell resistivity at high humidity is less than 0.1 Ω cm –2 . The mass activity (@ 0.85 V, Pt loading amount: 0.33 mg Pt cm −2 ) approaches 850 A g Pt –1 . The high gas crossover rate through the membrane leads to decreased open circuit voltage, which necessitates the use of higher Pt loadings (>0.30 mg Pt cm –2 ) at the cathode to mitigate the effect of the mixed potential. Pt degradation during 120 °C operation at low humidity is found to be much lower than that during 80 °C operation at high humidity based on the results of load–cycle durability testing.