MCMB/G制备DMFC管状阴极支撑体及电池性能

Preparation of a direct methanol fuel cell tubular cathode support from mesocarbon microbeads and graphite

  • 摘要: 采用中间相炭微球/石墨(MCMB/G)作为炭前驱体材料,采用凝胶注模成型工艺制备DMFC管状阴极支撑体素坯,并通过1 000℃埋炭烧结工艺制备了管状支撑体烧结体。在此基础上,采用涂覆和包覆工艺,分别制备了管状阴极和平板阳极,组装了膜电极和异型单电池。结果表明,所制备的管状阴极支撑体表面光滑且未变形;管状阴极表面的扩散层和催化层为多孔结构,大部分孔径处于亚微米级,这有利于传质和提高催化效率;通过组织和单电池性能研究,证实了MCMB/G作为异形阴极支撑体的可行性。

     

    Abstract: A tubular cathode support green body for tubular direct methanol fuel cell was prepared by a gel casting molding method using a mixture of mesocarbon microbeads and natural graphite powder with a mass ratio of 3∶2 as carbon precursor. It was sintered at 1 000 ℃ for 5 h in a graphite boat covered by graphite powder. Subsequently, a tubular cathode and a planar anode were obtained by coating the supports with slurry containing a catalyst and a Nafion membrane in a PTFE suspension. The catalysts for the cathode and anode are Pt/C and Pt-Ru/C, respectively. Results show that the surface of the tubular cathode support is smooth with no distortion. Both the gas diffusion layer and catalyst layer of the cathode show a similar porous structure with most of the holes in the sub-micron scale, which is favorable for decreasing mass transfer resistance and improving catalytic efficiency. A single cell performance test indicates that the sintered cathode bodies from the mixture of mesocarbon microbeads and graphite can be used as a special-shaped cathode support.

     

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