Carbonate dual-phase improves the performance of single-layer fuel cell made from mixed ionic and semiconductor composite

Abstract

Abstract A mixed ionic and semiconducting composite in a single-layer configuration has been shown to work as a fuel cell at a lower temperature (500-600 °C) than a traditional solid-oxide fuel cell. The performance of a single-layer fuel cell (SLFC) is often limited by high resistive losses. Here, an eutectic mixture of alkali-carbonates was added to SLFC to improve the ionic conductivity. The dual-phase composite ionic conductor consisted of a ternary carbonate (sodium lithium potassium carbonate, NLKC) mixed with gadolinium-doped cerium oxide (GDC). Lithium nickel zinc oxide (LNZ) was used as the semiconducting material. The LNZ-GDC-NLKC SLFC reached a high power density, 582 mW/cm² (conductivity 0.22 S/cm) at 600 °C, which is more than 30 times better than without the carbonate. The best results were obtained with the ternary carbonate which decreased the ohmic losses of the cell by more than 95%, whereas the SLFC with a binary carbonate (sodium lithium carbonate, NLC) showed a lower conductivity and performance (243 mW/cm², 0.17 S/cm at 600°C). It is concluded that adding carbonates to LNZ-GDC will improve the ionic conductivity and positively contribute to the cell performance. These results suggest a potential path for further development of SLFCs, but also imply the need for efforts on up-scaling and stability to produce practical applications with SLFC.

Key findings

• ▸[object Object]
• ▸[object Object]
• ▸[object Object]

Keywords

Identifiers

DOI

10.21203/rs.2.14603/v3

Journal

Research Square

Year

2020