Intermediate-Temperature Ceramic Fuel Cells with Thin Film Yttrium-Doped Barium Zirconate Electrolytes

TLDR

The study investigates the structural, microstructural, and fuel‑cell performance characteristics of anhydrous proton‑conducting yttria‑doped barium zirconate (BYZ) membranes. BYZ membranes (~100 nm thick) were fabricated by atomic layer deposition and pulsed laser deposition on micromachined Si substrates, incorporated into Pt/BYZ/Pt electrochemical cells with porous Pt electrodes, and tested from 200 °C to 450 °C. The ALD‑fabricated BYZ cells achieved 136 mW cm⁻² at 400 °C and the PLD‑fabricated cells 120 mW cm⁻² at 450 °C, the highest values reported at these temperatures, with performance differences attributed to surface morphology and interfacial microstructure.

Abstract

Structural and microstructural properties as well as the fuel cell performance of anhydrous proton conducting yttria-doped barium zirconate (BYZ) membranes were investigated. The membranes were nominally about 100 nm thick and were fabricated by both atomic layer deposition (ALD) and pulsed laser deposition (PLD) techniques on micromachined Si substrates. Electrochemical cells (H2, Pt/BYZ/Pt, air) were fabricated using porous platinum electrodes deposited by sputtering. The cells were tested in the temperature regime 200−450 °C. Power densities of 136 mW/cm2 at 400 °C employing a BYZ membrane fabricated by ALD and 120 mW/cm2 at 450 °C employing a BYZ fabricated by PLD clearly represent the highest reported values in the literature at these temperatures. The difference in the cell performances for the ALD BYZ versus PLD BYZ membranes is attributed to differences in their surface morphology and interfacial microstructure.