Symmetrical solid oxide cells (SSOCs) have recently gained significant attention for their potential in energy
conversion due to their simplified cell configuration, cost-effectiveness, and excellent reversibility. However, previous research efforts
have mainly focused on improving the electrode performance of perovskite-type electrodes through different doping strategies,
neglecting microstructural optimization. This work presents novel approaches for the nanostructural tailoring of
(La0.8Sr0.2)0.95Fe1−xTixO3−δ (LSFTx, x = 0.2 and 0.4) electrodes using a single-step spray-pyrolysis deposition process. By
incorporating these electrodes into a Ce0.9Gd0.1O1.95 (CGO) porous backbone or employing a nanocomposite architecture with
nanoscale particle size, we achieved significant improvements in the polarization resistance (Rp) compared with traditional screenprinted
electrodes. To further boost the fuel oxidation performance, a Ni-doping strategy, coupled with meticulous microstructural
optimization, was implemented. The exsolution of Ni nanoparticles under reducing conditions resulted in remarkable Rp values as
low as 0.34 and 0.11 Ω cm2 in air and wet H2 at 700 °C, respectively. Moreover, an electrolyte-supported cell with symmetrical
electrodes demonstrated a stable maximum power density of 617 mW cm−2 at 800 °C. These findings highlight the importance of
combining electrode composition optimization with advanced morphology control in the design of highly efficient and durable
SSOCs.