In-situ formed Ce0.8Sm0.2O2−δ@Ba(Ce, Zr)1−x(Sm, Y)xO3−δ core/shell electron-blocking layer towards Ce0.8Sm0.2O2−δ-based solid oxide fuel cells with high open circuit voltages

Chemically stable composite BaZr0.8Y0.2O3−δ–Ni (BZY–Ni) was proposed and evaluated as the anode for solid oxide fuel cells (SOFCs) based on Ce0.8Sm0.2O2−δ (SDC) electrolyte. A thin electron-blocking interlayer was formed in situ at the anode/electrolyte interface when the anode-supported half cell was prepared via a high-temperature sintering process. Raman spectra and high-resolution TEM (HRTEM) results revealed that the electron-blocking interlayer consisted of Ce0.8Sm0.2O2−δ@Ba(Ce, Zr)1−x(Sm, Y)xO3−δ core/shell-like grains. The Ba(Ce, Zr)1−x(Sm, Y)xO3−δ shell protected SDC grains from reduction and consequently the electronic conduction through the SDC electrolyte film was nearly completely eliminated in the new structured fuel cell. The fuel cell exhibited significantly improved open circuit voltages (OCVs), high power densities as well as good operating durability, demonstrating that BZY–Ni is a promising anode for CeO2-based SOFCs operating at a higher efficiency. These findings also imply that doped CeO2@doped Ba(Ce, Zr)O3 core/shell composite is a promising electrolyte with high ionic transport number, which directs a new strategy to design novel electrolyte materials for SOFCs.