Crack‐free cathode of intermediate‐temperature solid oxide fuel cells via electrospray deposition

Abstract

Cracks and delamination primarily revealed in the microscale‐thick cathode have been known as the major cause of increasing the polarization resistance and inhibiting the low‐temperature operation of solid oxide fuel cells (SOFCs). Besides, these defects were originated from the polymer dispersant, essential for the fabrication of the bulk cathode layer. Herein, we manufactured a crack‐free cathode layer by optimizing the deposition temperature (Tdep) of the powder‐suspension electrospray deposition (ESD) process through thermal characterization of polyvinylpyrrolidone (PVP), a polymer used in the slurry of ESD. SOFCs with the cathode deposited at the glass transition temperature of PVP resulted in a maximum power density of 0.481 W/cm2, 37% and 39% improved than those with the cathode deposited at Tdep = 25 and 200℃, respectively, at 650℃. Furthermore, the effect of uniformly dispersed morphology of cathode without defects was demonstrated by the reduction of polarization resistance through electrochemical impedance spectroscopy analysis.