Modelling and DC-polarisation of a three dimensional electrode/electrolyte interface

Abstract A finite element model (FEM) was developed which is able to calculate and predict the electrical performance of a solid oxide fuel cell (SOFC) with a three dimensional interface between cathode and electrolyte. An enlargement of the electrochemical active surface leads to a significant increase of the electrical performance of a SOFC. Various three dimensional electrolyte/electrode interfaces have been realized by first screen printing of individual 10YSZ particles onto a flat and dense 8YSZ substrate. Surface enlargements between 10 and 50% have been realised and investigated. Second, a screen printed cathode (LSM) layer was applied as a current collector and gas distribution layer. In order to develop a FEM-model for this type of cathode/electrolyte interface, several electrical properties of cathode (LSM) and electrolyte (8YSZ) were examined. Further on, measurements of symmetrical cells (LSM/8YSZ/LSM) to evaluate the electrode resistance R 0 were carried out for different symmetrical cells. Taking into account the enlargement of the interface surface, electrical conductivity and electrode resistance R 0 , the entire DC polarisation-resistance R pol could be calculated by FEM.