The Effect of LSM Nanoparticles on SOFC Cathode Performance

Abstract

Nanoparticles of La1-xSrxMnO3{plus minus}¸ (LSM) were developed in the hopes that their high surface area would translate into enhanced oxygen reduction (ORR) kinetics when used as SOFC cathode materials. A novel sol gel derived synthesis was developed to produce both powders and a sol of LSM. Two distinct cathode fabrication approaches were utilized in this work in an effort to test the effects of sintering temperature. The first involved the pre-calcination of LSM nanopowders at 900 åC that were than subjected to the same high temperatures commonly used to sinter micron-sized LSM:YSZ electrodes. The second made use of a two stage sintering process, where the nano LSM component was introduced into a pre-sintered YSZ matrix by a liquid phase impregnation technique, which was followed by low temperature calcination. A comparison of the electrochemical activities between conventional LSM and LSM:YSZ cathodes has shown that higher ORR rates are obtainable by utilization of LSM nanoparticles.