纳米TiO_2复合膜的制备及在燃料电池中的应用

Preparation of Nano-TiO_2 Composite Membrane and its Application in Fuel Cell

利用溶胶-凝胶法与加温、加压-流延工艺成功地制备出锐钛矿与金红石2种TiO2的质子交换复合膜。通过XRD,FTIR,EDS和AFM方法研究了复合膜晶形信息、化合键信息、元素分布、表面粗糙度,并组装了燃料电池进行了电化学测试。实验表明:TiO2掺杂全氟磺酸树脂的复合膜能在干气的操作条件下自增湿发电,电化学稳定,最高功率密度超过1W/cm2;而且发现在复合膜中掺杂物的晶形影响燃料电池的自增湿发电性能,在70℃,0.2MPa,化学计量数为1.5的干H2/干O2操作环境下,锐钛矿型复合膜在0.55V下的电流密度接近2A/cm2,比金红石型复合膜增大了0.34A/cm2,表现出了优良的自增湿电化学性能。最后讨论了TiO2/PFSA复合膜的质子传递机理。

Two kinds of Nano-TiO2/PFSA composite membranes （anatase and rutile） were successfully fabricated by the methods of Sol-Gel and Tape-Casting. XRD, FTIR, EDS and AFM were used to study the physical chemistry performances of the self-humidifying composite membranes. Single proton exchange membrane fuel cells were assembled for evaluating the electrochemical performance of the composite membranes. The results indicate that the performances of TiO2/PFSA composite membranes were excellent and stable and the peak power density was more than 1.0 W/cm^2 for dry H2/dryO2. The experiment also showed that the crystal structure of TiO2 influenced the performance of the TiO2/PFSA composite membrane with a current density of 2 A/cm^2 for the anatase composite membrane, 0.34 A/cm^2 higher than that of the rutile composite membrane at the conditions of 0.55 V, 70℃, 0.2 MPa, 1.5 stoichiometry and in dry H2 and dry O2. Finally, the proton transfer mechanism of composite membrane was discussed.