Optimization of functional layers for SOFC by PLD

Abstract

The deposition of thin layers on solid oxide fuel cells (SOFCs) has proved as a highly relevant method for improvement of the fuel cell's performance. Physical vapour deposition methods (PVD) such as pulsed laser deposition (PLD) have emerged to fabricate thin and dense electrolyte and functional barrier films as they enable a great control of stoichiometry and microstructure. Recently, a protective barrier layer of gadolinium-doped ceria (GDC) has been proposed to prevent unwanted interfacial reactions between the state-of-the-art electrolyte, yttria-strabilized zirconia (YSZ), and the cathode, lanthanium strontium cobalt ferrite (LSCF). However, the fabrication step of the barrier layer and adjacent components of the cell requires control as cation interdiffusion commonly occurs through the pores and grain boundaries of the GDC barrier. Such thermally activated processes lead to a rapid degradation of the cell limiting its potential for application. It is therefore essential to apply an effective barrier layer that enhances the performance of the cells and minimizes interdiffusion. The focus of this research internship at IREC (Catalonia Institute for Energy Research) will be on the fabrication of thin and dense barrier layers deposited by the PLD method in large area planar SOFCs and the improved cell will be tested in realistic conditions to evaluate its application aiming at upscaling of the PLD technique. IREC is one of the key institutions worldwide to develop SOFCs using the PLD method and our group at IPEN recently installed a PLD system. Therefore, the internship is an excellent opportunity to train students in this powerful technique and to exchange knowledge through scientific collaboration. (AU)