Properties of Nafion® NR-211 membranes for PEMFCs
Properties of Nafion® NR-211 membranes for PEMFCs
复制标题
DOI：
10.1016/j.memsci.2010.03.025
复制
发表时间：
2010-07
影响因子：
9.5
通讯作者：
J. Peron;A. Mani;Xinsheng Zhao;D. Edwards;M. Adachi;T. Soboleva;Zhiqing Shi;Zhong Xie;T. Navessin;S. Holdcroft
中科院分区：
文献类型：
--
作者：
J. Peron;A. Mani;Xinsheng Zhao;D. Edwards;M. Adachi;T. Soboleva;Zhiqing Shi;Zhong Xie;T. Navessin;S. Holdcroft
Nafion®211是许多燃料电池用户的参考膜，但关于其性能的文献很少。不像以前的实施方案的Nafion®膜，这是通过熔融挤压获得，Nafion®211是通过分散铸造制备。本文报道了通过非原位和原位表征方法获得的一系列性质。研究了水分吸收和质子电导率随温度和相对湿度的变化规律。发现在水化作用下接收膜的尺寸变化程度与热处理无关。在25°C和97%相对湿度下，最大水化数为~ 12。从液态水和蒸气的吸收被观察到相似。据报道，Nafion®211的质子电导率高达80°C，并作为相对湿度的函数。在80℃时，当相对湿度从10%增加到95%时，电导率从0.0012增加到0.13S/cm。70℃时，Nafion®211的渗透率为2.4×10−16m2Pa−1s−1，渗透率为8.8×10−12mPa−1s−1。在30°C， 100% RH和30psi氧气条件下，使用固态电化学电池研究的氧溶解度和扩散系数分别为1.6×10−5molcm−3和1.04×10−6cm2s−1。在相同条件下，氧渗透率为1.71×10−11molcm−1s−1。在80°C和100% RH下，氢气交叉电流的原位测量为1.2mA/cm2。
Nafion®211 is the membrane of reference for many fuel cell users, but the literature on its properties is sparse. Unlike previous embodiments of Nafion®membranes, which are obtained by melt extrusion, Nafion®211 is prepared by dispersion casting. This paper reports a range of properties obtained by ex situ and in situ characterization methods. Water uptake and proton conductivity are studied as a function of temperature and relative humidity. The extent of dimensional changes of as-received membranes upon hydration is found to be independent of thermal treatment. At 25°C and 97% RH the maximum hydration number is ∼12. Absorption from liquid water and vapour are observed to be similar. Proton conductivity for Nafion®211 is reported up 80°C and as a function of relative humidity. At 80°C, the conductivity increases from 0.0012 to 0.13S/cm as RH is increased from 10 to 95%. The hydraulic permeability of Nafion®211 is 2.4×10−16m2Pa−1s−1at 70°C and the permeance is 8.8×10−12mPa−1s−1. Oxygen solubility and the diffusion coefficient, studied using a solid state electrochemical cell, are 1.6×10−5molcm−3and 1.04×10−6cm2s−1at 30°C, 100% RH, and 30psi oxygen. Oxygen permeability is 1.71×10−11molcm−1s−1under similar conditions. In situ measurement of hydrogen crossover current is 1.2mA/cm2at 80°C and 100% RH.