A semiconductor heterostructure material based on p-type cubic perovskite Ba0.9K0.1Fe0.5Co0.5O3-δ (BKFC) and n-type fluorite Sm0.075Nd0.075Ce0.85O2-δ (SNDC) forms micro p-n junctions in the low-temperature solid oxide fuel cells (LT-SOFCs) improving the electrochemical performance. A highly power density of 911 mW·cm−2 at 550° C was obtained with this material combination as electrolyte in a fuel cell, which is 20 % higher than that of the LT-SOFCs with pure BKFC as electrolyte. An ionic conductivity of 0.14 S·cm−1 at 550° C was achieved when equal amounts of BKFC and SNDC were employed as the electrolyte. Profound analysis of the heterostructure p-n junction shows that it blocks electron transport through mixed electronic and ionic conductor and enhances ionic transport improving the electrochemical performance of the fuel cell. The BKFC-SNDC composite electrolyte materials is a potential electrolyte material for raising the power density of fuel cells at lower temperatures.
- Fluorite structure
- P-n junction, Heterostructure
- Perovskite structure