Sc-doping strategy for LaNi_0.5Fe_0.5O_3- cathode to boost the performance of proton-conducting solid oxide fuel cells

LaNi0.5Fe0.5O3-delta (LNF) is a viable option for the cathode of solid oxide fuel cells (SOFCs), however, its performance in proton-conducting SOFCs (H-SOFCs) is not sufficient. In this work, an Sc-doped method to increase the cathode performance of conventional LNF for H-SOFCs is proposed. Although the Sc cation can be doped at the Ni site or the Fe site in LNF, which led to the formation of pure phase materials, first-principles calculations indicate that the formation of the LaNi0.4Sc0.1Fe0.5O3-delta (LNSF) material has more advantages than the formation of the LaNi0.5Fe0.4Sc0.1O3-delta (LNFS) material, even though the same Sc-doping level is employed. Compared to Sc-free LNF, LNSF provides superior fuel cell performance. At 700 degrees C, the LNSF cell generates a peak power density of 1534 mW cm(-2), double that of the LNF cell. In addition, employing the LNSF cathode reduces the cell's polarization resistance, indicating that the Sc-doping strategy paired with selecting the doping site is an effective method for reusing LNF in high-performance H-SOFCs. (c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.