A large set of single-layer fuel cells utilizing lithium nickel zinc oxide (LNZ) as semiconducting material and doped ceria -based ionic conductors with varying composition were fabricated and characterized by both microscopic and macroscopic methods. Microstructural analysis showed that LiNiO, LiZnO and doped ceria formed crystalline phases, whereas alkali carbonates were in amorphous state. The ionic conductivity of the cell was found to be the most crucial performance-limiting factor. Using of catalytically active current collector improved the cell performance if the ionic conductivity through the cell was suitable. Controlling the porosity and optimizing the mass ratio of semiconductor and ionic conductor affected the cell performance as well. An optimized device achieved a power density of 300 mW/cm2 at 600 °C.
- Single-layer fuel cell
- Varying composition