Anodic properties of Ni-Fe bimetallic nanofiber for solid oxide fuel cell using LaGaO3 electrolyte

Abstract

Solid oxide fuel cells (SOFCs) are attracting much attention as alternative energy conversion devices owing to their high energy conversion efficiency and fuel flexibility. Currently, Ni-based cermets or Ni-based bimetal are often being used as anode materials for SOFCs. However, in anode materials, metallic spherical particles generally agglomerate, which affects the electrode reaction under reduction conditions at high temperature. Furthermore, such agglomeration affects both microstructure of the electrode and the cell stability. To overcome this problem, in this study, we designed a bimetallic anode and fabricate it by electrospinning. This Ni-Fe fiber anode exhibits enhanced anodic activity and tolerance to coarsening of metallic particle compared to the Ni-Fe spherical powder. The ohmic and polarization resistance of Ni-Fe fiber anode is lower than Ni-Fe powder anode at all operation temperature. In addition, the single cell using Ni-Fe fiber anode shows higher maximum power densities of 0.40, 0.80, and 1.64 W/cm2 at 973, 1073, and 1173 K, respectively. Such enhanced power generation properties and lower resistance originated from continuous pathways for excellent charge transport pathways generated by electrospinning and the enhanced gas-diffusion properties of the nanofibers. These results demonstrate that the introduction of Ni-Fe fiber anode in SOFCs is an effective approach to enhance their power generation properties and stability. © 2021 Elsevier B.V.