Effect of La0.8Sr0.2Co0.2Fe0.8O3−δ morphology on the performance of composite cathodes

In the present work, one dimensional La0.8Sr0.2Co0.2Fe0.8O3−δ (LSCF) nanofibers with the mean diameter of about 100 nm prepared by electrospinning were deposited on Gd0.2Ce0.8O1.9 (GDC) electrolyte followed by sintering to form one dimensional LSCF nanofiber cathode. And LSCF/GDC composite cathodes were formed by introducing GDC phases into LSCF nanofiber scaffold using infiltration method. The polarization resistances for the composite cathode with an optimal LSCF/GDC mass ratio of 1/0.56 are 0.27, 0.14 and 0.07 Ω cm2 at 650, 700 and 750 °C, respectively, which are obviously smaller than 2.26, 0.78 and 0.29 Ω cm2 of pure LSCF nanofiber cathode. And the activation energy is 1.194 eV, which is much lower than that of pure LSCF nanofiber cathode (1.684 eV). These results demonstrate that the infiltration of GDC into LSCF nanofiber scaffold is an effective approach to achieve high performance cathode for solid oxide fuel cells (SOFCs). In addition, the performance of composite cathode in this work was also compared with that of our previous nanorod structured LSCF/GDC composite cathode.