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 (T-dep) 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/cm(2), 37% and 39% improved than those with the cathode deposited at T-dep = 25 and 200celcius, respectively, at 650celcius. Furthermore, the effect of uniformly dispersed morphology of cathode without defects was demonstrated by the reduction of polarization resistance through electrochemical impedance spectroscopy analysis.