直接甲醇燃料电池阳极动态响应的原位测试及衰减机理分析

项目名称： 直接甲醇燃料电池阳极动态响应的原位测试及衰减机理分析

项目编号： No.21276036

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 化学工业

项目作者： 黄乃宝

作者单位： 大连海事大学

项目金额： 80万元

中文摘要： 直接甲醇燃料电池（DMFC）阳极是决定电池性能、寿命和成本的关键材料之一。阳极性能常采用模拟环境进行评价，而离线环境下的评价结果既不能真实反映在线工况下的状态，又不能提供电极微小区域的信息，因而很难从本质上揭示实际加载状态下阳极的变化过程。为了解实际工况下电极的性能、分析其衰减机理，本课题创新性的实现DMFC阳极在线状态下的原位测试，即采用扫描电化学显微镜（SECM）和局部交流阻抗（LEIS）原位测试阳极在线状态下的动态响应，并以三维图像展现电极性能的变化。检测电极特征参数（如催化层表面电子结构、尺寸、形貌等）的变化，分析影响其性能的敏感参数。进一步运用量子化学密度泛函理论，计算催化金属原子轨道的变化，从分子水平上揭示电极性能衰减的机理。课题的实施对实现燃料电池关键零部件的在线测试、指导催化剂选择和电极制备、提高电池性能和寿命具有重要的理论和实际意义。

中文关键词： 燃料电池；扫描电化学显微镜；局部交流阻抗；密度泛函理论；

英文摘要： Direct methanol fuel cell (DMFC) anode is one of the key materials that control fuel cell's characteristic, service life and costs. Its characteristic is often evaluated in simulated environment. These results gotten from off-line environment can't reflect the real state of anode at operating mode and provide micro-area information of anode. Thus, it is difficult to reveal the process of anode change under operating environment. In order to explain the degradation mechanism of anode, In situ test of DMFC anode is conducted under operating mode. That is, online current data of anode are recorded by Scanning Electrochemical Microscopy (SECM) and Localized Electrochemical Impedance Spectroscopy (LEIS) during loading. The anode changes are actualized in 3D imaging. Also, anode characteristic parameters such as surface electronic structure, size, morphology of catalyst, are also analyzed during this process. Based on these data, the main factors influencing its performance are analyzed. Also, orbital change of catalyst is calculated by density functional theory. Based on these results, the degradation mechanism is revealed at molecular level. These conclusions have an important theoretical and practical significance on selecting catalyst, preparing anode and improving fuel cell performance and service life.

英文关键词： Fuel cell；Scanning Electrochemical Microscopy；Localized Electrochemical Impedance Spectroscopy；Density Functional Theory；