Thin Film Fuel Cell Based on Nanometer-Thick Membrane of Amorphous Zirconium Phosphate Electrolyte

Abstract

Novel thin film fuel cell based on the 100 nm-thick electrolyte of amorphous ZrP2.6Ox, working at 400°C, was demonstrated. The hydrogen permeable membrane fuel cell (HMFC) using a Pd foil as a nonporous solid anode was fabricated. Ni interlayer of several hundreds nm thickness was introduced between the Pd anode and the ZrP2.6Ox electrolyte in order to suppress the deterioration of the electrolyte nanofilm by the deformation of the Pd anode during hydrogen absorption. In the ZrP2.6Ox electrolyte the transport number of proton was unity at 400°C as determined by an EMF measurement. The modification of the Ni anode surface by an ultrathin Pt or Pd layer effectively decreased the anode/electrolyte interfacial polarization. Consequently, the HMFC revealed the OCV of 1.0 V and the maximum power density of 1.8 mW cm−2 at 400°C.