共查询到19条相似文献,搜索用时 203 毫秒
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质子交换膜燃料电池由于具有能量转换效率高、操作温度低、环境友好等优点而备受人们关注。随着2014年丰田发布燃料电池电动汽车Mirai,带来了新一轮燃料电池及燃料电池汽车的产业化热潮。然而,提升质子交换膜燃料电池的寿命,开发新一代长寿命燃料电池膜电极及燃料电池仍然是本领域的挑战性课题。膜电极(MEA)是质子交换膜燃料电池最核心的部件,其耐久性直接决定着燃料电池的寿命。MEA主要由质子交换膜、催化剂层、气体扩散层三部分组成。本文从质子交换膜、催化剂及载体、气体扩散层三个方面介绍了近年来国内外在提升燃料电池膜电极的寿命(耐久性)方面所做的工作,并对未来的相关研究和发展做了述评及展望。 相似文献
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质子交换膜燃料电池催化剂层在成本、耐久性以及性能上的局限是制约燃料电池汽车商业化的瓶颈. 已有文献证明静电纺丝技术制备的纳米纤维催化剂层能提高催化剂利用率、增加三相界面和三相通道以及提高耐久性. 作者结合所在课题组的工作综述了静电纺丝技术制备质子交换膜燃料电池催化剂层的研究进展. 首先,介绍了质子交换膜燃料电池催化剂层的发展历程,并从制备方式和结构两个方面对其进行分类和总结;接下来,从静电纺丝纳米纤维催化剂层的制备、物理特性表征、电化学性能分析及耐久性表征等方面进行了总结;最后,从三相界面、三相通道以及量产适用性的视点比较了三种结构的催化剂层,介绍了质子交换膜燃料电池催化剂层的发展趋势,并梳理了静电纺丝法制备质子交换膜燃料电池催化剂层领域待研的问题. 相似文献
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Tongtao Wang Caishun Lin Feng Ye Yong Fang Jingjing Li Xindong Wang 《Electrochemistry communications》2008,10(9):1261-1263
Methanol permeation is one of the key problems for direct methanol fuel cell (DMFC) applications. It is necessary to change the structure of the cathode of membrane electrode assembly (MEA). Therefore, a novel MEA with double-layered catalyst cathode was prepared in this paper. The double-layered catalyst consists of PtRu black as inner catalyst layer and Pt black as outer catalyst layer. The inner catalyst layer is prepared for oxidation of the methanol permeated from anode. The results indicate that this double-layered catalyst reduced the effects of methanol crossover and assimilated mixed potential losses. The performance of MEA with double-layered catalyst cathode was 52.2 mW cm−2, which was a remarkable improvement compared with the performance of MEA with traditional cathode. The key factor responsible for the improved performance is the optimization of the electrode structure. 相似文献
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《Electrochemistry communications》2007,9(4):718-724
The supply of cathode reactants in a passive direct methanol fuel cell (DMFC) relies on naturally breathing oxygen from ambient air. The successful operation of this type of passive fuel cell requires the overall mass transfer resistance of oxygen through the layered fuel cell structure to be minimized such that the voltage loss due to the oxygen concentration polarization can be reduced. In this work, we propose a new membrane electrode assembly (MEA), in which the conventional cathode gas diffusion layer (GDL) is eliminated while utilizing a porous metal structure for transporting oxygen and collecting current. We show theoretically that the new MEA enables a higher mass transfer rate of oxygen and thus better performance. The measured polarization and constant-current discharging behavior showed that the passive DMFC with the new MEA yielded better and much more stable performance than did the cell having the conventional MEA. The EIS spectrum analysis further demonstrated that the improved performance with the new MEA was attributed to the enhanced transport of oxygen as a result of the reduced mass transfer resistance in the fuel cell system. 相似文献
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Nicholas W. DeLuca Yossef A. Elabd 《Journal of Polymer Science.Polymer Physics》2006,44(16):2201-2225
The direct methanol fuel cell (DMFC) has the potential to replace lithium‐ion rechargeable batteries in portable electronic devices, but currently experiences significant power density and efficiency losses due to high methanol crossover through polymer electrolyte membranes (PEMs). Numerous publications document the synthesis and characterization of new PEMs for the DMFC. This article reviews this research, transport phenomena in PEMs, and experimental techniques used to evaluate new PEMs for the DMFC. Although many PEMs do not show significant improvements over Nafion®, the benchmark PEM in DMFCs, experimental results show that several new PEMs exhibit lower methanol crossover at similar proton conductivities and/or higher DMFC power densities. These results and recommendations for future research are discussed. © 2006 Wiley Periodicals, Inc. J Polym Sci Parts B: Polym Phys 44: 2201–2225, 2006 相似文献
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Platinum and/or metal‐oxide nanocrystals (d = 1 ‐ 2 nm) were highly dispersed in membranes such as a Nation® commercially available (denoted as Pt‐PEM or Pt‐oxide‐PEM) attempting to self‐humidify the PEMs and/or to suppress the short‐circuit reaction by a catalytic oxidation of the crossover hydrogen or methanol with oxygen on the Pt catalyst. High and stable performances under the suppressed crossover and lowered internal resistance are demonstrated at the H2/O2 fuel cells applied Pt‐PEM or Pt‐oxide‐PEM without any external humidification. An appreciable increase of the cathode potential due to the reduced methanol crossover was clearly demonstrated at a direct methanol fuel cell (DMFC) with Pt‐PEM. It also becomes clear that the development of new PEMs with lowered permeability against methanol is essential for DMFCs. 相似文献
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设计并组装单电池寿命测试系统,测试直接甲醇燃料电池(DMFC)的运行寿命,获得不同运行时间下单电池的极化和功率曲线.测试结束后,分别对运行过的膜电极(MEA)催化剂(铂黑和铂钌黑)和Nafion117(膜作XRD,HRTEM,FTIR及Raman等表征.考察在长期运行条件下电池寿命性能与膜电极中催化剂的颗粒大小、分布、形态、表面物种以及膜的结构之间的关系.寿命测试结果表明,单电池在不同运行阶段其性能变化也不同.运行前200 h,电池性能衰减较显著;运行200~704 h性能较稳定,运行1 002 h后电池性能恶化.波谱实验发现,单电池长期运行后,其膜电极的阴、阳极催化剂颗粒变大.电池寿命性能的衰退伴随膜电极微结构、表面组成、催化剂/膜界面结构的变化以及Nafion 117(膜的老化. 相似文献
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《Electrochemistry communications》2008,10(10):1606-1609
Direct methanol fuel cell (DMFC) consisting of a double-catalytic layered membrane electrode assembly (MEA) provide higher performance than that with the traditional MEA. This novel structured MEA includes a hydrophilic inner catalyst layer and a traditional electrode with an outer catalyst layer, which was made using both catalyst coated membrane (CCM) and gas diffusion electrode (GDE) methods. The inner catalyst was PtRu black on anode and Pt black on cathode. The outer catalyst was carbon supported Pt–Ru/Pt on anode and cathode, respectively. Thus in the double-catalytic layered electrodes three gradients were formed: catalyst concentration gradient, hydrophilicity gradient and porosity gradient, resulting in good mass transfer, proton and electron conducting and low methanol crossover. The peak density of DMFC with such MEA was 19 mW cm−2, operated at 2 M CH3OH, 2 atm oxygen at room temperature, which was much higher than DMFC with traditional MEA. 相似文献
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杂多酸修饰的电极对于甲醇电氧化的促进作用 总被引:4,自引:0,他引:4
采用杂多酸修饰光滑铂电极,研究其对甲醇电催化氧化的作用,发现与未修饰光滑铂电极相比,分别经磷钨酸和硅钨酸修饰的电极上甲醇电催化氧化速率明显增加. 相似文献