【作者】 李国华；

【导师】 王宇新；

【作者基本信息】 天津大学 ， 化学工程， 2003， 硕士

【摘要】 燃料电池以其能量转化率高、低排放、能量和功率密度高等优点被认为是适应未来能源和环境要求的理想动力源之一。双极板是燃料电池的重要组成部分，它为电池分配燃料与氧化剂并串联相邻电池，其成本可占总成本的约 40%，而燃料电池的高成本正是其走向实用化的一大障碍。寻找性能优良且成本低廉的双极板新材料和加工方法已成为燃料电池产业化技术研究中的重要课题。本论文针对现有双极板成本高的问题，在开发高性能、价廉的燃料电池双极板材料和工艺方面进行了一些新的探索和尝试。论文以导电性和阻气性作为双极板性能的衡量标准，首先从工艺的角度，研究了不同混合方法、不同热压条件及不同冷却方法对鳞片石墨/树脂复合板性能的影响。其次，本文从材料的角度，研究了不同树脂含量、不同树脂材料、不同树脂熔体流动指数以及不同鳞片石墨颗粒大小对鳞片石墨/树脂复合板性能的影响。实验发现树脂材料的流动性以及石墨颗粒的接触电阻是影响复合板导电性的重要因素，而复合板的孔隙率则是影响其阻气性的重要因素。另外，本文还考察了电池工作电流下复合板性能的变化，为本复合材料应用于燃料电池时，其电阻值的稳定性提供了依据。研究取得了极具开发前景的结果，本文提出的鳞片石墨/树脂复合双极板一步模压成形技术大大减少了双极板的加工成本。其所制出的PP-NG和PVDF-NG复合板的导电性和阻气性在树脂含量分别为 8wt%-25wt%和 13wt%-34wt%时，均能达到燃料电池的使用标准，但其成本将远低于硬质石墨板，这将为燃料电池提高经济竞争力和走向实用化奠定基础。更多还原

【Abstract】 Fuel cell (FC) is recognized as a new alternative to the present power sourcesbecause of its high efficiency, low emission, high energy and power density. Bipolarplate is an important part in FC, which distributes fuel and oxidant for FC andprovides electronic connection between single cells. Its cost accounted for about40% of a FC stack, while the high cost of FC is a key obstacle to its wide application.Therefore, searching materials and manufacturing methods for high performance andlow cost bipolar plate has been very important. With the above background, newmaterials and manufacturing methods for bipolar plates are explored in this study. The performance of bipolar plates is evaluated in view of their electronicconductivity and H2 permeability. The study began with technological conditionresearch and the effect of mixing method, hot pressing conditions and coolingmethods on the plate’s performance was investigated. Then the effect of resincontent, resin type, their melt flow index and grain size of the graphite on the plate’sperformance was investigated. It is discovered that the resin’s fluidity and the contactresistance of the graphite grain are two important factors that greatly influence theplate’s conductivity while the permeability is highly influenced by the plate’sporosity. In addition, the plates were tested under normal current density that a fuelcell can possibly reach, to make sure the conductivity of the composite plates stableunder fuel cell environment. Encouraging results are achieved in regards that the proposed naturalgraphite/resin composite plate will be suitable for FC and their cost can be highlydecreased by the method of one-step press molding. The PP-NG and PVDF-NGplates produced by this way, with the potential of much lower cost compared withconventional bipolar plate of hard graphite, meet the requirement of PEM fuel cellwhen the resin content is 8wt%-25wt% and 13wt%-34wt% respectively. These willhelp to make fuel cell more economically competitive.更多还原