Addition of sulfonated silicon dioxide on an anode catalyst layer to improve the performance of a self-humidifying proton exchange membrane fuel cell

Abstract

Sulfonated SiO2 was added on an anode catalyst layer to manufacture a hygroscopic electrode for self-humidifying proton exchange membrane fuel cells (PEMFCs). The inherent humidity of a proton exchange membrane (PEM) determines the electrical performance of PEMFCs. To maintain the high moisture content of the PEM, self-humidifying PEMFCs can use the water produced by the fuel cell reaction and, thus, do not require external humidification. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and water contact angle measurement tests were performed to characterize the structures and properties of sulfonated SiO2 and the related electrodes, and the electric current and voltage (I–V) performance curve tests for the fuel cells were conducted under differing gas humidification conditions. When 0.01[Formula: see text]mg/cm2 of sulfonated SiO2 was added, the electrical performance of the fuel cells (50[Formula: see text]C) increased 29% and 59% when the fuel cell reaction gases were humidified at 70[Formula: see text]C and 50[Formula: see text]C, respectively.