如今消费者对便携式、高能耗(智能手机、平板电脑以及可穿戴设备)设备续航的需求极大的刺激了研究机构和企业在微小型高能量密度能源方面的研究。发展微小型电子设备能源的迫切需求使得众多学者开始进行微型燃料电池相关方面的研究。在所有的燃料电池种类中，微型直接甲醇燃料电池(Micro Direct Methanol Fuel Cell，μDMFC)拥有着燃料来源丰富、能量密度高、环境友好、启动及运行温度较低、燃料存储、运输方便等独特的优越性。随着近几十年微电子机械系统(Micro Electro Mechanical System，MEMS)技术和材料科学的飞速发展，μDMFC的效率和稳定性更是得到了极大的提升。然而，目前μDMFC技术尚未得到大面积推广，离大规模商业化还有一定的距离，其主要的技术瓶颈在于功率密度较低、成本、便携性以及燃料实际使用浓度较低四个问题。本文围绕μDMFC电化学特性优化、复杂度优化以及便携性优化等基本方向，制备并测试了一种新型金属编织物膜电极，实现了一种集流板-膜电极一体化新结构；设计并实现了一种基于超疏水金属表面改性工艺的微通道排气结构；设计并制备了一种超亲水端板μDMFC。这些工作对μDMFC的功率密度提升、复杂度降低以及便携性提升具有重要意义。 首先，本文对不同电池结构下阴阳极反应物及产物的浓度分布和电流密度分布进行了理论计算分析。与常规电池结构的μDMFC对比分析表明，集流板-膜电极一体化μDMFC表现出了更高的阴阳极产物传质速率，微通道排气式μDMFC展现了优异的气体排出能力，超亲水金属基μDMFC体现了非常快速的水扩散速率，理论分析结果与后续实验测试规律相吻合。 其次，采用新型金属编织物代替常规碳纤维编织物，制备了一种金属编织物膜电极，其机械强度使得μDMFC可以不再需要昂贵的阴阳极集流板即可进行电流引出，大幅降低了μDMFC的结构复杂度，实现了一种集流板-膜电极一体化新结构。同时金属编织物膜电极优良的阴极多孔结构使得该种新型膜电极在室温下有着优异的性能表现，对采用了金属编织物膜电极的一体化μDMFC测试结果表明，与作为对照组的常规碳纸膜电极μDMFC相比，大幅提升了续航时间，且室温25℃下的最大功率密度提升了33.9％，能量转换效率提升至27.36％。 随后，通过铝基超疏水工艺，实现了一种具有侧排气微通道的阳极端板结构，该结构使得CO₂可以不经过流场直接由阳极扩散层轻松排出，大幅提升了μDMFC低浓度大电流工况下的极化特性和电压输出稳定性。带有微通道侧排气结构的μDMFC相比较于常规结构，稳定性及最大输出电流皆有显著提升。根据电池的不同封闭程度，10％以上的阳极废气CO₂可经由微通道顺利排出，使得阳极燃料腔可以成为全封闭式，避免了燃料电池在便携使用过程中的燃料泄露，优化了燃料电池工作情况下的可便携性。 最后基于铝基底，采用等离子体电解氧化技术制备了一种μDMFC超亲水金属阴极端板。结合阴极端板排水微流道设计，使得室温大电流下的μDMFC阴极水淹现象消失，μDMFC长时间放电下性能提升了30％以上。半电池测试数据表明该μDMFC阴极表面电势十分稳定，阳极电势下降速度仅有常规电池的1／4。并且由于阴极产物水的有效处理，燃料电池运行期间的便携性大幅提升。 关键词：微型直接甲醇燃料电池；膜电极；不锈钢纤维毡；微通道排气；等离子体电解氧化技术

 At present, battery life demand for the portable and high energy-consumption (smart phones, tablet computers and wearable devices) device has greatly stimulated researchers and enterprises to study micro-sized and high energy-density energy. The urgent need to develop micro-sized and high-density energy has led many scholars to start the research on micro-fuel cell. Micro Direct Methanol Fuel Cell (μDMFC), as one of the representatives of new energy, has unique advantages at such as abundant fuel source, high energy density, environment friendly, low start-up and operating temperature, convenient fuel storage, transportation, etc. With the rapid development of material science and Micro Electro Mechanical System (MEMS) technology in recent decades, the efficiency and stability of μDMFC have been greatly improved. However, at present, μDMFC technology has not been widely promoted, there is still a certain distance from large-scale commercialization. The main technical bottlenecks are the low power density, cost, portability and the low fuel concentration in practice. Foucs on the improvement of μDMFC electrochemical characteristics, complexity and prortability, a new type of metal fiber membrane electrode is prepared and tested. A lateral venting configuration based on super hydrophobic metal surface is designed and realized. A new μDMFC super hydrophilic end plate has been designed and prepared. These works are of great significance for the μDMFC power density increase, complexity reduction and portability. First, the reactants/products concentration distribution and current density distribution of anode and cathode with different structures were simulated and analyzed in this paper. Simulation results show that the current collectors and MEA integrated μDMFC have higher mass transfer rate, the laterval venting μDMFC shows excellent gas removal ability, the super hydrophilic metal μDMFC shows very fast water diffusion rate. Simulation results are consistent with the following experimental test results. Second, a metal fiber MEA is prepared by replacing the traditional carbon fiber MEA. Its mechanical strength characteristic gurantees the elimination of the expensive anode and cathode collector plate in the μDMFC, greatly lowing the structural complexity of the μDMFC, implement the current collectors and MEA interated configuration. At the same time, the excellent cathode porous structure of metal fiber electrode lead to an excellent performance at room temperature. Test results show that, comparing with traditional carbon paper film electrode μDMFCs, the discharging time extends a lot. And at room temperature 25℃, the maximum power density increased by 33.9 % and the energy conversion efficiency to 27.36 %. Third, by aluminum based superhydrophobic process and micro channel structure design, an anode end plate structure with lateral venting micro channels is realized. CO₂ can easily vent from anode diffusion layer without flow field, greatly improving the polarization characteristics and voltage output stability of μDMFC. More than 10 % CO₂ can vent from the lateral venting channels, making the totally enclosed anode liquid storage possible, avoiding fuel leakage in the process of portable use of the fuel cell, optimizing the portability of the fuel cell. Finally, based on the aluminum alloy substrate, a super hydrophilic metal cathode end plate has been prepared. Combined with the design of micro drainage channel, the cathod flood phenomenon of μDMFC disappeared at room temperature, the performance of μDMFC increased more than 30 % during long discharging. Half-cell test results show that the cathode potential is very stable, the anode potential drop rate is only 1/4 of the conventional battery. Moreover, due to the effective treatment of cathode production, the portability of fuel cell during operation is greatly improved. Keywords: micro direct methanol fuel cell, membrane electrode, stainless steel fiber felt, micro channel venting, plasma electrolytic oxidation technology