Surface modification of carbonaceous materials and their use in polymer electrolyte fuel cells and hydrogen-air secondary batteries

Surface modification techniques for carbonaceous materials such as composites, Ketjen black, and vapor grown carbon fibers (VGCFs) are introduced and their use in polymer electrolyte fuel cells (PEFCs) and hydrogen-air secondary batteries are reviewed. A graphite powder/resin composite used as a bipolar plate of PEFCs is corroded with the evolution of CO sub(2) over 1.3 V in a dilute HClO sub(4) solution at 80 [degrees]C. A tin oxide coating is found to be effective in preventing corrosion. A similar effect of a tin oxide coating is also found for Ketjen black as the electrode catalyst support of PEFCs. Furthermore, after loading Pt as the catalyst it is found that the tin oxide coating of Ketjen black gives better catalytic activity. O-Methylated Ketjen black is prepared and its performance as the catalyst support is also discussed. VGCFs decorated with LaMnO sub(3) are also prepared and have promise as the electrode material for a hydrogen-air secondary battery.