Application of Screen-Printed Catalytic Electrodes to MEMS-Based Fuel Cells

Abstract

This paper describes trials to realize a MEMS-based polymer electrolyte fuel cell (PEFC) with Pt-loaded carbon electrodes. We first developed screen-printing technology to pattern Pt-loaded carbon electrodes on MEMS-based PEFCs. Iso-propyl alcohol (IPA) and dibutyl phthalate (DBP) were compared as the dispersion media of Pt-loaded carbon powder. We found that DBP-based paste had better screen-printability, and revealed the reason by measuring the relationship between the shear rate and viscosity of the pastes. Next, we applied the Pt loaded carbon paste to two types of MEMS-based PEFCs. One is the PEFC which uses porous SiO₂ as a gas diffusion layer. The Pt-loaded carbon paste was screen-printed on the Pt current collector which was sputter-deposited on the porous SiO₂. The obtained power density was only 70 μW/cm². The other type of MEMS-based PEFC is a thin film PEFC. A Pt-loaded carbon anode and cathode were screen-printed on a silicon/Pyrex glass support substrate. The obtained power density was 1.5 μW/cm². The low performance may be due to the low performance of the prepared Pt-loaded carbon, and/or the poor adhesion of the anode with the current collector and the PEM. For the thin film PEFC, the high resistance of the Pt-loaded carbon electrodes can be another reason, because there are no current collector on the Pt-loaded carbon electrodes.