Studies on Electrocatalysts, MEAs and Compact Stacks of Direct Alcohol Fuel Cells

A number of carbon supported bi/multi-metallic Pt-based electrocatalysts with a metal particle-size and shape controllable in nanoscale and a narrow size distribution were prepared by the improved polyol method. Among the electrocatalysts prepared in-house, PtSn/C showed a high direct ethanol fuel cell performance and PtPd/C exhibited a favorable methanol-tolerant property and oxygen-reduction activity. Several MEA fabrication methods such as direct-spray, decal and screen-printing were developed, through which the pore structure and hydrophilic/hydrophobic properties in the MEAs could be controlled desirably. With multi-layer structured electrodes, the maximum power density of 300 mW/cm² and 240 mW/cm² for the single cells were achieved at 90 °C under 0.2 MPa pressures of oxygen and air, respectively. Several demonstrations of active and passive compact DMFC systems ranging from sub-watts to 200 watt were fabricated. Some of them were demonstrated in PDA, toy cars, mobile phones and laptop computers.