Metal-supported solid oxide fuel cells (SOFCs) are one of the most promising candidates for applications in power plants as well as in portable applications due to their good mechanical and thermal properties. A Ni-supported SOFC that consists of a metal support (Ni, similar to 180 mu m), an anode functional layer (Ni-yttrium stabilized zirconia YSZ, similar to 15 mu m), an electrolyte (YSZ, similar to 5 mu m), and a nanocrystalline La0.6Sr0.4CO0.2Fe0.8O3-delta (LSCF) cathode is prepared. A nanocrystalline LSCF synthesized with ethylenediaminetetraacetic acid, citric acid, and inorganic nanodispersants, is used as an in situ sinterable cathode. The Ni-supported SOFC with nanocrystalline LSCFs is operated without a high temperature treatment for cathode sintering. The cell exhibits the maximum power density of 580 mW cm(-2) at 780 degrees C. A current treatment for 8 h (0.5 A cm(-2) at 780 degrees C) enhances the interfacial contact between the cathode and the electrolyte. After the current treatment, the maximum power density at 730 degrees C increase by 1.6 times from 260 mW cm(-2) to 390 mW cm(-2). The ohmic resistance (R-ohm) at 730 degrees C decreases from 0.43 Omega cm(2) to 0.21 Omega cm(2) and the charge transfer polarization at 0.7 V decreases from 0.42 Omega cm(2) to 0.30 Omega cm(2) due to lowered interfacial resistance between the cathode and the electrolyte. However, the mass transfer polarization increases from 0.09 Omega cm(2) to 0.17 Omega cm(2), which may result from the morphological change in the porous microstructure of the Ni support. The current treatment of the Ni-supported SOFC with in situ sintered LSCFs exhibit an increment in fuel cell performance due to the lowered ohmic resistance, which is beneficial for simple and mechanically improved fabrication and operation of metal-supported SOFCs. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.