Uncovering proton transportation enabled via the surface and interfacial engineering for ceramic fuel cells.

Ultra-wide bandgap semiconductor Ceria oxide attracts tremendous interest because of its high stability and electrical properties. The ionic transport properties of CeO 2 have tremendously been elaborated in terms of electrolytes, especially using bulk doping like Sm doped Ceria and gadolinium doped Ceria, but challenges remain. In this work, we propose the surface doping of Sn into CeO 2 for the engineering of the electronic structure of CeO 2 with a focus on surface properties. The Sn doping into CeO 2 enables the Fermi-level to lower level, which further induces a local electric field, dramatically enhancing the surface proton transport at the surface and interface. Furthermore, higher concentrations of Oxygen vacancies and lattice disturbance on the surface layer are mainly ascribed to surface modification, which eventually promotes proton transport. The prepared fuel cell device based on Ce 0.9 Sn 0.1 O 2 as an electrolyte has delivered a total high performance of 905 mW cm−2 and proton performance of 787 mW/cm2 along with an ionic and protons conductivity of 0.21 and 0.19 S cm−1 at 520 °C. The surface doping of Sn in CeO 2 builds continuous surfaces as proton channels for high-speed transport. This work presents a reasonable methodology to develop high-performance, low-temperature ceramic fuel cells. [Display omitted] • CeSnO 2 was synthesized using the sol-gel technique. • The designed cell has a high ionic conductivity of 0.21 S/cm at 520 °C. • The proposed device has delivered a remarkable power output of 905 mW/cm2 520 °C. • Formation of BIEF due to surface doping dramatically enhances the surface's proton transport. • The DFT calculation was performed to assist the experimental results. [ABSTRACT FROM AUTHOR]