A review of key parameters for effective electrophoretic deposition in the fabrication of solid oxide fuel cells

This paper reviews recent progress in electrophoretic deposition (EPD), particularly in solid oxide fuel cells (SOFCs). EPD is a simple, cost-effective, and geometrical flexible colloidal process. With its excellent control of thickness and other morphological characteristics, it is favored for the fabrication of SOFCs because each component layer of an SOFC has different requirements. However, the effectiveness of EPD is closely related to the suspension stability and EPD processing parameters. Maintaining a stable suspension and optimizing the EPD processing parameters are essential to achieve a dense and uniform deposition layer. Key parameters in maintaining the suspension stability are generally categorized into colloidal related parameters, including particle size and solid loading, and suspension media related parameters, including dielectric constant and conductivity. The effects of these parameters are often reflected by the zeta potential of the suspension, which can be manipulated by using charging agents to maintain a stable state. The deposition time and applied voltage are key parameters in optimizing the EPD process through their effects on the deposition rate. The effects of these parameters on particle surface charges and on the EPD mechanism are discussed.