A Study On The Durability Of Electrode For PEMFC

Proton exchange membrane fuel cells (PEMFCs) are promising in energy efficiency, high energy density, no liquid electrolyte corrosion, low temperature quick starting, compacting structure and so on. It has a wide application prospect in electric vehicles, ground stations, underwater submarine and communication power. The main issues are the cost and life, especially in automotive operation at any time when the load changes, the life drops significantly. Now, the best life of PEMFC is 2200h, there being a great distance from the life of 5000h. Therefore, studying failure mechanism of the fuel cell, finding solutions to improve the fuel cell life, promoting the commercialization of fuel cell and reducing environmental pollution is of great significance.Catalyst durability had been studied by Predecessors and they had gained extensive conclusions. This article focuses on the durability of Nafion electrolyte. Nafion as electrodes'catalyst has different crystallinities at different temperatures. And it has a better stability after high temperature treatment. So change the degree of crystallinity of Nafion to enhance the stability of Nafion by changing electrode post-processing temperature, in order to achieve improving the purpose of the durability of the electrode. In addition, PEMFC catalyst support of the corrosion resistance has been studied. The difficulty of Graphite nanofibers (GNF) as a PEMFC's support is not nano-scale particles. GNFs'corrosion resistance at room temperature had been studied. This article focuses on preparing GNF using method of high-energy ball milling; wet grinding, studying the durability of GNF at high-temperature (80℃), and conducting the feasibility of GNF as PEMFC catalyst support.Electrode life testing is studied. The results show that scanning 1000 circle CV in acidic solution environment is an ideal testing method of life, because the electrode performance can be attenuated 57%. By studying post-processing temperature of the electrodes, the electrodes protecting in the N2 atmosphere, constant heating 30min, and heating in the temperature of 180℃have better electrochemical performance, single-battery performance, life expectancy, as well as electrochemical corrosion resistance; The TEM of this electrode shows that its Pt particles are more evenly distributed under these conditions.The wasted carbon papers are recycled and production rate of 84%. GNF are prepared by the wet high-energy ball milling method. The TEM shows the prepared GNF have been reached nano-particles degree. The EIS shows that the resistance of GNF is the smallest. The comparison among GNF, CNTs and XC-72 shows that GNF have better corrosion resistance.