Fabrication and Characterization of Nanoporous LSM Cathode for SOFC by Electrostatic Spray Deposition

초록

Lanthanum strontium manganate (LSM) is the most widely used cathode material in solid oxide fuel cells (SOFCs). However, the polarization resistance of LSM increases dramatically from 1Ωcm-2 at 1000 oC to 2000 Ωcm-2 at 500 oC. Nowadays, three approaches have been developed to overcome this problem. One way is to find mixed conducting materials such as LSCF. Another way is to form composite electrode with a high electron-conducting phase mixed with a highly ionic conducting phase. The other way is the control of microstructure between electrolyte and electrodes and thin film technique are essential in order to minimize interfacial resistances. In this paper, electrostatic spray deposition was applied to prepare nano-porous LSM layers for SOFCs cathode. Deposition parameters were optimized to obtain porous cathodes with high specfic area. The electrochemical performance of LSM cathodes was characterized by AC impedance and DC polarization in the temperature range of 546 oC to 777 oC.