Interlayer Conducting Mechanism in α-LiAlO₂ Enables Fast Proton Transport with Low Activation Energy for Solid Oxide Fuel Cells

Abstract

The α-NaFeO 2 structure-type oxides, such as LiNiO 2 , LiCoO 2 , and α-LiAlO 2, could not only provide channels for Li + conduction but also conduct protons through intercalation. However, the detailed conduction mechanism of protons in the layer structure oxide needs to be further distinguished. In this work, we prepared layered-oxide α-Li 0.88 AlO 2 and used it as an electrolyte to assemble a solid oxide fuel cell (SOFC), which delivered an output of 1046 mW cm −2 at 550 °C, a decent power output is ascribed to the excellent ion conductivity (0.2 S cm −1 ) and low activation energy (0.36 eV) of the α-Li 0.88 AlO 2 electrolyte. Moreover, the H/ D isotope experiments revealed that the proton dominated the ion conduction of α-Li 0.88 AlO 2. First-principles calculations indicate that the special structure-layered oxides provide channels that allow protons to transfer rapidly with low activation energy. This work indicates the possibility of using layered oxides as proton conductors in a low-temperature SOFC (LT-SOFC) and reveals the proton transport mechanism in oxides, it provides a new approach to exploit novel electrolytes for LT-SOFC.

Tailored Double Perovskite with Boosted Oxygen Reduction Kinetics and CO2 Durability for Solid Oxide Fuel Cells

“…1,2 SOFC offers a range of application scenarios, such as functioning as power sources for buildings and automobiles. 3,4 Moreover, SOFCs possess the capacity to function in reverse mode, allowing for the conversion of electricity back into chemical energy. 5,6 At present, SOFCs are usually operated at high temperatures (850−1000 °C) to output sufficient power density.…”

“…Solid oxide fuel cell (SOFC) is widely acknowledged as a prospective energy transformation technology exhibiting the qualities of remarkable energy conversion efficiency, fuel diversity, absence of noble metal catalysis, and environmental friendliness. , SOFC offers a range of application scenarios, such as functioning as power sources for buildings and automobiles. , Moreover, SOFCs possess the capacity to function in reverse mode, allowing for the conversion of electricity back into chemical energy. , …”