Selection of cathode materials for forsterite supported solid oxide fuel cells - Part Ⅰ: Materials interactions

摘要

An inert-supported cell (ISC) was developed by Bosch with the aim of lowering the manufacturing costs of SOFCs and thus increasing their marketability and prolonging their lifetime. This ISC concept uses forsterite, a magnesium silicate doped with Zn and Ca, as support material. The cell can be described as air side inert-supported cell, since forsterite faces the air compartment.Forsterite was chosen as a support material, as it is abundant and therefore relatively inexpensive. All functional layers are subsequently applied and co-sintered at T < 1300 degrees C to further reduce cell manufacturing costs.At present, LSM is used as a cathode. However, the performance of the cell is drastically reduced due to the formation of a Zn-Mn spinel at the triple-phase boundaries during co-firing.Based on these findings, seven different cathodes were synthesized to identify a cathode that is less reactive with forsterite. In order to investigate their reactivity, different types of samples were prepared: mixed pellets, double-layered pellets and screen-printed cathode inks on forsterite green substrates. These samples and their cross sections were then investigated by using XRD, SEM, EDX, and WDX. Their reactivity was as follows (ascending order): LSFM > LSF > LSC > PSCF > LSCF > LCCF.