Direct-write microfabrication of single-chamber micro solid oxide fuel cells

Abstract

Single-chamber micro solid oxide fuel cells (SC-µSOFCs) are promising systems for portable power generation. Here we report the direct-write microfabrication and electrochemical testing of SC-µSOFCs in the single-face configuration which consists of closely spaced interdigitated electrodes on an electrolyte substrate. In direct-write microfabrication, powdered electrode materials are first synthesized into inks which are subsequently extruded through a micronozzle onto an electrolyte plate mounted on a robot-controlled platform. The microfabricated structures are then sintered to remove the organic components of the inks and to obtain porous electrodes. Processing–structure relationships were obtained using systematic experimentation for the direct-write microfabrication of nickel oxide–yttria stabilized zirconia (NiO–YSZ) anodes and lanthanum strontium manganite (LSM) cathodes on an YSZ electrolyte. Single-chamber µSOFCs were fabricated with interdigitated electrodes of a few hundred microns in size. When tested in a fuel–air mixture (methane-to-oxygen ratio Rmix = 2) at a furnace temperature of 700 °C, the cells exhibited an open circuit voltage of 800 mV and a peak power density of ∼1 mW cm−2. Implications for the use of these devices for portable power generation are discussed.