Enhancing Samarium-Doped Ceria Electrolytes with Manganese for Solid Oxide Fuel Cell

Abstract

This study focuses on synthesizing new electrolyte materials for solid oxide fuel cell (SOFC) with the composition of Ce0.8-x MnxSm0.2O1.9-δ (x = 0, 0.025, 0.05, 0.1). The main aim is to investigate the effect of varying molar concentrations of manganese (Mn) as a secondary dopant on density, phase composition, and ionic conductivity of samarium-doped ceria (SDC). Accordingly, X-ray diffraction (XRD) and impedance spectroscopy (IS) were employed to characterize the samples. Mn-doped samples sintered at 1400°C for 5 hours exhibited a single-phase cubic fluorite structure with larger lattice parameters and volumes compared to the undoped sample. All samples achieved a high relative density exceeding 94%. Notably, the sample with 10 mol% Mn reached a relative density of 99.6%. Impedance data revealed that the ionic conductivity of the Mn-doped samples was enhanced by an order of magnitude compared to the undoped samples. This indicates that Mn is a promising dopant for SDC in electrolyte applications for SOFCs.