Fabrication and performance of PEN SOFCs with proton-conducting electrolyte

A positive-electrolyte-negative (PEN) assembly solid oxide fuel cell (SOFC) with a thin electrolyte film for intermediate temperature operation was fabricated. Instead of the traditional screen-printing method, both anode and cathode catalysts were pressed simultaneously and formed with the fabrication of nano-composite electrolyte by press method. This design offered some advantageous configurations that diminished ohmic resistance between electrolyte and electrodes. It also increased the proton-conducting rate and improved the performance of SOFCs due to the reduction of membrane thickness and good contact between electrolyte and electrodes. The fabricated PEN cell generated electricity between 600°C and 680°C using H₂S as fuel feed and air as oxidant. Maximum power densities 40 mW·cm⁻² and 130 mW·cm⁻² for the PEN configuration with a Mo-Ni-S-based composite anode, nano-composite electrolyte (Li₂SO₄+Al₂O₃) film and a NiO-based composite cathode were achieved at 600°C and 680°C, respectively.