An Interface Heterostructure of NiO and CeO2 for Using Electrolytes of Low-Temperature Solid Oxide Fuel Cells

Interface engineering can be used to tune the properties of heterostructure materials at an atomic level, yielding exceptional final physical properties. In this work, we synthesized a heterostructure of a p-type semiconductor (NiO) and an n-type semiconductor (CeO2) for solid oxide fuel cell electrolytes. The CeO2-NiO heterostructure exhibited high ionic conductivity of 0.2 S cm(-1) at 530 degrees C, which was further improved to 0.29 S cm(-1) by the introduction of Na+ ions. When it was applied in the fuel cell, an excellent power density of 571 mW cm(-1) was obtained, indicating that the CeO2-NiO heterostructure can provide favorable electrolyte functionality. The prepared CeO2-NiO heterostructures possessed both proton and oxygen ionic conductivities, with oxygen ionic conductivity dominating the fuel cell reaction. Further investigations in terms of electrical conductivity and electrode polarization, a proton and oxygen ionic co-conducting mechanism, and a mechanism for blocking electron transport showed that the reconstruction of the energy band at the interfaces was responsible for the enhanced ionic conductivity and cell power output. This work presents a new methodology and scientific understanding of semiconductor-based heterostructures for advanced ceramic fuel cells.

Automated summary

Interface engineering was utilized in this study to create a CeO2-NiO heterostructure with high ionic conductivity for solid oxide fuel cell electrolytes. The heterostructure exhibited excellent power density and favorable electrolyte functionality, attributed to the reconstructed energy band at the interfaces, showcasing the potential of semiconductor-based heterostructures for advanced ceramic fuel cells.