Pore-forming technology and performance of MEA for direct methanol fuel cells
Pore-forming technology and performance of MEA for direct methanol fuel cells
复制标题
DOI：
10.1002/jctb.3906
复制
发表时间：
2013-05-01
影响因子：
3.4
通讯作者：
Wang, Xin-Dong
中科院分区：
文献类型：
--
作者：
Liu, Gui-Cheng;Wang, Yi-Tuo;Wang, Xin-Dong
背景：dmfc功率密度相对较低，严重制约了其商业化发展。在高效催化剂、流道优化设计、新型质子交换膜的开发和Nafion膜的改性等方面进行了大量的研究。同时，关于膜电极组件（MEA）结构优化的报道很少。为了提高直接甲醇燃料电池（dmfc）的性能，以碳酸铵为成孔剂，对阳极和阴极催化剂层（CL）结构进行了优化。结果：极化曲线显示，在55℃、0.2 MPa O2条件下，催化剂浆中碳酸铵的最佳含量为50 wt%， DMFC性能由75.65 mW cm2提高到167.42 mW cm2。电化学阻抗谱和电化学活性表面积（EASA）测试表明，优化后的mea性能的提高主要是由于EASA的增加和传质速率的提高。但甲醇交叉性能差限制了多孔阳极mea的性能提高。结论：在提高电池性能方面，该成孔技术更适合应用于阴极催化剂层以改善其结构，而非阳极催化剂层。(c) 2012年化学工业学会
BACKGROUND: The commercialization of DMFCs is seriously restricted by its relatively low power density. Lots of work has been concentrated on catalysts with high activity, the optimization of flow path design, development of new kinds of proton exchange membrane and modification of Nafion membrane. Meanwhile, very few reports have involved the structure optimization of the membrane electrode assembly (MEA). To improve the performance of direct methanol fuel cells (DMFCs), the catalyst layer (CL) structures of anode and cathode were optimized by utilizing ammonium carbonate as pore forming agent. RESULTS: The polarization curves showed that in catalyst slurry the optimal content of ammonium carbonate was 50 wt%, and the DMFC performance was enhanced from 75.65 mW cm2 to 167.42 mW cm2 at 55 degrees C and 0.2 MPa O2. Electrochemical impedance spectroscopy and electrochemical active surface area (EASA) testing revealed that the improved performance of optimized MEAs could be mainly attributed to the increasing EASA and the enhanced mass transfer rate of CLs. But poor methanol crossover limited the performance enhancement of MEAs with porous anodes. CONCLUSION: With regard to improving cell performance, this pore-forming technology is better applied to the cathode catalyst layer to improve its structure rather than the anode catalyst layer. (c) 2012 Society of Chemical Industry