New Technologies of DMFC

对液体酒精燃料电池进行了深入的研究。醇比氢更适合作为燃料，因为我们很容易储存和运输。本项目主要研究直接甲醇燃料电池(DMFC)和直接乙醇燃料电池，以支持其实用化。首先总结了制约DMFC实用化的因素：(1)发电效率低，(2)功率密度低，(3)材料成本高，(4)体积太大，不适合便携式应用，(5)甲醇的毒性。在此基础上，设计了解决问题的五个基本途径。它们是：(1)减少甲醇越界；(2)开发高电流密度电极和高温电解液材料；(3)减少直接甲醇燃料电池电极上的铂负载量；(3)开发不含贵金属的新型催化剂；(4)微型化微机械燃料电池的开发；(5)直接乙醇燃料电池的研究。FO-…通过本项目的实施，这5个问题都得到了较好的解决方案。(1)开发了一种新型膜--填充孔膜，其膜分离性能优于高浓度甲醇燃料(约10M)。(2)开发了一种新型的具有多孔碳衬底的直接甲醇燃料电池，以减少甲醇的越界，单电池即使在高甲醇浓度下(高达17M)也表现出高的I-V性能。(3)利用自组织技术在碳纳米管表面制备了APT/SnOx催化剂。这种纳米结构有望降低直接甲醇燃料电池中的铂负载量。(4)设计并制作了基于MEMS技术的新型微型直接甲醇燃料电池。这种技术减少了DMFC中的组件数量，降低了组装成本，并减小了它们的尺寸。(5)对直接乙醇燃料电池进行了研究，考察了阳极反应中间产物乙醛的行为。这一分析所获得的知识有助于实现直接乙醇燃料电池。较少

The fuel cells for liquid alcohol fuels are studied intensively. Alcohols are more suitable for fuels than hydrogen because we easily store and transport. In this project direct methanol fuel cells (DMFCs) and direct ethanol fuel cells are mainly investigated in order to support the efforts to develop their practical use. First the factors preventing the practical use of DMFCs are summarized as: (1) low efficiency for power generation, (2) low power density, (3) high material cost, (4) too large for portable applications, (5) toxicity of methanol. Then the basic 5 approaches were designed to solve the problems. They are : (1) reduction of the methanol cross over, (2) development of a high current density electrode and high temperature electrolyte materials, (3) reduction of the platinum loading on the DMFC electrodes, and development of new catalysis without containing precious metals, (4) development of MEMS fuel cells for miniaturization, (5) studying direct ethanol fuel cells.The fo … More llowing solutions for the 5 problems were obtained as the result of this project. (1) A new type of membrane namely the pore-filling membrane was developed, and its MEA gives high performance with high concentration methanol fuel (around 10M). (2) A novel DMFC with a porous carbon substrate was developed to reduce the methanol cross over, and the single cell showed a high I-V performance even at high methanol concentration (as high as 17M). (3) APt/SnOx catalyst was synthesized on a well controlled surface of carbon nano-tubes by self-organization. Such nano-structure is promising for the reduction of Pt loading in DMFCs. (4) Novel micro DMFCs based on MEMS technology were designed and fabricated. This technology reduces the number of the components in a DMFC and reduces the assembly cost as well as reduces their sizes. (5) A direct ethanol fuel cell is studied and the behavior of the acetaldehyde which is an intermediate product in the anode reaction was investigated. The knowledge obtained in this analysis contributes to the realization of direct ethanol fuel cells (DEFCs). Less