A new high-performance proton-conducting electrolyte for next-generation solid oxide fuel cells

Conventional solid oxide fuel cells (SOFCs) are operable at high temperatures (700 – 1,000 °C) with the most commonly used electrolyte, yttria‐stabilized zirconia (YSZ). SOFC R&D activities have thus been carried out to reduce the SOFC operating temperature. At intermediate temperatures (400 – 700 °C), barium cerate (BaCeO₃) and barium zirconate (BaZrO₃) are good candidates for use as proton‐conducting electrolytes due to their promising electrochemical characteristics. Here, we combined two widely studied proton‐conducting materials with two dopants and discovered an attractive composition for the investigation of electrochemical behaviors. Ba_0.9Sr_0.1Ce_0.5Zr_0.35Y_0.1Sm_0.05O_3‐δδ(BSCZYSm), a perovskite‐type polycrystalline material, has shown very promising properties to be used as proton‐conducting electrolytes at intermediate temperature range. BSCZYSm shows a high proton conductivity of 4.167×10⁻³ S cm⁻¹ in a wet argon atmosphere and peak power density of 581.7 mW cm⁻² in Ni‐BSCZYSm | BSCZYSm | BSCF cell arrangement at 700 °C, which is one of the highest in comparison to proton‐conducting electrolyte‐based fuel cells reported till now.