Preparation and properties of Nafion/SiO2 composite membrane derived via in situ sol–gel reaction: size controlling and size effects of SiO2 nano‐particles |
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| Authors: | Chang‐Chun Ke Xiao‐Jin Li Shu‐Guo Qu Zhi‐Gang Shao Bao‐Lian Yi |
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| Institution: | 1. Laboratory of Fuel Cell System and Engineering, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China;2. Graduate School of Chinese Academy of Sciences, Beijing 100049, China |
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| Abstract: | A novel technique in controlling the size of SiO2 nano‐particles in the preparation of Nafion/SiO2 composite membranes via in situ sol–gel method, as well as the effects of nano‐particle size on membrane properties and cell performance, is reported in this paper. Nafion/SiO2 composite membranes containing SiO2 nano‐particles with four different diameters (5 ± 0.5, 7 ± 0.5, 10 ± 1, and 15 ± 2 nm) are fabricated by altering the reactant concentrations during in situ sol–gel reaction. Sequentially, size effects of SiO2 nano‐particles on membrane properties and cell performance are investigated by SEM/EDAX, TEM, TGA, mechanical tensile, and single cell tests, etc. The results suggest that 10 nm is a critical diameter for SiO2 incorporated into Nafion matrix, exhibiting desirable physico‐chemical properties for operation at elevated temperature and low humidity. At 110°C and 59% RH, the output voltage of the cell equipped with Nafion/SiO2 (10 nm) obtains an output voltage of 0.625 V at 600 mA/cm2, which is 50 mV higher than that of unmodified Nafion. Copyright © 2010 John Wiley & Sons, Ltd. |
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| Keywords: | proton exchange membrane fuel cell in situ sol– gel Nafi on/SiO2 composite membrane SiO2 nano‐particle size effect |
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