Development of electroless plating process for multiscale solid oxide fuel cell anode fabrication

Abstract

The purpose of this thesis is to develop an electroless plating process to implement a multiscale fuel electrode by plating nanoscale metal particles onto a microporous substrate. In previous research performed by other groups, a small amount of co-catalysts, such as Ag and Cu, was applied for the electrode. These researchers focused on catalysts for activating the surface reaction. In contrast, in this thesis, we present a process to implement a multiscale fuel electrode by electrolessly plating nickel, which is utilized as the main catalyst of the fuel electrode, to form a continuous nanoscale particle network. In Chapter 3, research investigating the stability of plating bath additives was conducted to identify appropriate additives for stable and slow plating characteristics. In Chapter 4, we focused on confirming the possibility of using electroless plating to produce Ni-LSGM multiscale electrodes. A microstructure analysis, X-ray diffraction pattern analysis, and impedance spectroscopy measurements were performed to determine the possibility of nickel electroless plating. In Chapter 5, we attempted to investigate how to remove the gas bubbles generated inside the microporous substrate by applying ultrasonication rather than the improvement of the 2-D surface characteristics. We attempted to fabricate an MS-SOFC cell by adopting the ultrasonic-assisted electroless plating process. When ultrasonication was applied, penetrating the plating bath solution to the TPB region was possible due to the effective removal of the bubble. Furthermore, the ohmic resistance was confirmed to be dramatically reduced compared with the case in which ultrasonication was not applied (~1/4.2 times lower ohmic resistance) because the nickel particles, which had been plated only on the surface by gas generation during the electroless plating process, could be plated on the inside of the anode substrate due to the proper bubble removal characteristics after the ultrasonication application.