【作者】 石劲松；

【导师】 田建华；

【作者基本信息】 天津大学 ， 应用化学， 2007， 硕士

【摘要】 质子交换膜燃料电池(PEMFC)具有高能量密度、运行温度低和稳定性能好等优点。为使PEMFC能够早日实现商品化生产,各国科研工作者正在致力于相关材料的研究,力图降低PEMFC成本,提高PEMFC的性能。本文研究了催化层组成对PEMFC性能的影响。制备了不同Nafion载量的膜电极,通过对其性能的研究,优化了催化层中Nafion载量。为了进一步改善膜电极性能,尝试了在催化层中加入PTFE的方法。实验结果表明,加入少量的PTFE能对膜电极内的水分进行调节,使PEMFC在高电流密度时性能得到改善。本文开发了一种制备水管理层(Water Management Layer, WML)的新工艺。该工艺的主要特点是直接形成薄膜状WML,从而摆脱传统WML制备方法以碳纸为基底的限制。研究了该工艺各工艺参数,包括烧结温度、烧结时间、WML薄膜厚度以及组成等对PEMFC性能的影响。用PEMFC单体的电流密度-电压曲线评价了含有WML薄膜的膜电极的极化特性。实验结果表明,含有WML薄膜的膜电极性能与含有涂覆法制备的WML的膜电极性能相近,从而肯定了WML薄膜水管理能力。本文还研究了制备催化层时使用不同有机溶剂对PEMFC性能的影响。通过对三种不同有机溶剂制备的膜电极性能的考察,表明溶剂的介电常数值对膜电极性能有重要的影响,适中的介电常数值对PEMFC性能更有利。更多还原

【Abstract】 Proton exchange membrane fuel cell (PEMFC) has significant advantages such as high power density, low operating temperature and excellent stability. In order to bring the commercialization of PEMFC into reality, researchers all over the world are endeavoring to develop related materials to decrease the cost and improve the performance of PEMFC.The effects of composition of catalyst layer on PEMFCs’performances were investigated in this article. Membrane electrode assemblies (MEAs) with different Nafion loadings were fabricated, Nafion loading in catalyst layer was optimized through the research of performances of MEAs. In order to improve MEA’s performance, PTFE was added into catalyst layer. The experiment results demonstrated PTFE could improve water distribution in MEA, and cell performance in high current density range was improved efficiently.A new process for the preparation of water management layer (WML) was developed in this article, in which a filmy WML was prepared separately avoiding the limitation of independence on carbon paper. Influences of several parameters including sintering time, sintering temperature, thickness and composition of WML film on PEMFC’s performance were researched. The polarization characteristic of MEA with WML film was evaluated using the polarization plot of a single PEMFC. As shown in the experiment results, MEA with WML film had similar performance as MEA with WML prepared by traditional brushing method, which confirmed the water management ability of the WML film.Effects of different organic solvents applied for the preparation of catalyst layer on cell performance were investigated in this article. Performances of MEAs fabricated with three different solvents were researched, and the results indicated that dielectric constant of organic solvent had an important influence on cell performance, solvents with medium dielectric constant were more favorable for good performance.更多还原