Preparation of nano-crystalline strontium-doped lanthanum manganate (LSM) powder and porous film by aerosol flame deposition

To improve the performance of the cathode, many groups have studied the relationship between the cathode microstructure and the electrochemical performance. In this study, a porous La0.8Sr0.2MnO3±δ (LSM) cathode film with primary particles of under 10 nm diameters was prepared by aerosol flame deposition (AFD). The AFD technique was applied to synthesize the spherical particles and dense LSM thin film. The cathode performance was improved, and the polarization resistance was decreased by extending the active triple phase boundary. The electrochemical characteristics were investigated in the temperature range of 600-900 °C and oxygen partial pressure range of 0.1-1.0 atm. For oxygen reduction reaction on the LSM cathode, it was turned out that both oxygen atom diffusion and oxygen ion transfer from the three phase boundary to the yttria-stabilized zirconia electrolyte lattice were the rate-determining steps with comparable contributions. The polarization resistance of the prepared LSM film decreased from 206 to 1.7 Ω cm2 with increasing temperature from about 600 to 900 °C and the activation energy was 1.48 eV.