A Proton Conducting Solid Oxide Electrolysis Cell with Tri-Doping Electrolyte and Three-Phase Conducting Steam Electrode for Sustainable Hydrogen Production

Abstract

Proton conducting solid oxide electrolysis cell (P-SOEC) is an emerging technology that enables sustainable hydrogen production at reduced operating temperatures (400~600 ○C). Economically competitive P-SOEC systems have distinct advantages over conventional oxygen-ion conducting counterpart (O-SOEC), but further technology development and widespread market acceptance will require continuous innovation of materials in order to improve cell performance, enhance system lifetime and reduce cost. In this work, a new type of tri-doping barium-zirconium-cerate electrolyte and a triple phase conducting steam electrode are explored as material candidates. The material synthesis, pellet sintering, and electrical conductivity are carried out to evaluate the feasibility as an electrolyte. For the triple phase conducting electrode, the conduction behavior and catalytic activity towards water splitting reaction are studied. In addition, these two materials are incorporated into P-SOEC button cells and the electrochemical performance is evaluated under different operating conditions (temperature, humidity, feed gas composition, etc). The long-term durability in high steam pressure is also carried out to examine the stability of the material system. Such an early-stage R&D showed feasibility of hydrogen production systems for field operations and the ability to cost effectively produce hydrogen at the scale needed to support military operations.