Compact Direct Alcohol Fuel Cells for Portable Power Sources

Fuel cells, as a kind of highly efficient and environment-friendly energy conversion system, have been considered as alternative powers sources for transportation and electric devices. Due to the worldwide efforts paid on fuel cells R&D during recent decades, the commercialization of several kinds of fuel cells has been put on agenda. In our institute, the research mainly focus on three kinds of fuel cells, namely, proton exchange membrane fuel cell (PEMFC), direct alcohol fuel cell (DAFC) and solid oxide fuel cell (SOFC). The recent advancements in terms of electrocatalysts, polymer electrolyte membranes, membrane and electrode assemblies (MEAs), stacks and systems of different types of fuel cells were presented. Some of strategies to prepare Pt-based electrocatalysts with desired crystal facets, binary and ternary alloyed electrocatalysts with high activity and stability as well as non Pt electrocatalysts like MoN/C and FeN/C with promising activities were developed. Novel multi-layer structured MEAs were designed and fabricated to overcome the issue of fuel crossover and to further improve the performance, stability and durability of the fuel cells. In addition, by means of modularization in system, a series of components, such as methanol sensor, gas/liquid seperator, electronic controller and technologies including assembly of stacks with high consistency, feeding with high concentration methanol, water balance, heat management, intelligent power management, etc. were developed. And a number of compact systems of PEMFC, SOFC and DAFC ranging from sub-watts to hundred kilowatts in power were demonstrated. The remained issues for mass commercialization of the fuel cells in technology are primarily discussed such as stability, reliability, durability and cost etc