Boosting the Electrochemical Activity of BSMO Cathode by Compositing (Sm0.20Ce0.50Bi0.30)2O3+δ for Low Temperature Solid Oxide Fuel Cell

Abstract

Among energy conversion devices solid oxide fuel cells (SOFCs)are promising candidates due to their fuel flexibility and highly efficient; though, but their commercial application is limited due the high temperature. In this research work barium and strontium based low temperature solid oxide fuel cells (LT-SOFCs) were fabricated and characterized as cathode material for LT-SOFCs. Solid state method was adopted to synthesize barium strontium manganese oxide (Ba₀.₇₅Sr₀.₂₅MnO)₃−δ (BSMO) and (Sm₀.₂₀Ce₀.₅₀Bi₀.₃₀)₂O₃+δ (SCBO) was synthesized via the reverse co-precipitation route. The crystallographic crystal of the synthesized material was analyzed by employing XRD and all the samples shows highly crystalline structure. The characteristic vibrational modes of Sm-O, Ba–O, Ce-O, and Mn–O were confirmed from Raman spectroscopy. The BSMO, SCBO and BSMO/SCBO composite were fabricated via solid state mixing and electrochemical impedance spectroscopy (EIS) spectroscopy measurements were recorded with in the temperature range 400oC-700oC and enhanced electrochemical characteristics of the SCBO material was observed. It was observed that the BSMO/SCBO composite exhibited lower polarization resistance compared to pristine BSMO and SCBO within the temperature range of 550°C –650 °C, that results the improved ionic–electronic conductivity balance and enhanced charge transfer. DC conductivity measurements showed the semiconducting behavior of BSMO material and reduce and stable conductivity for SCBO, and intermediate conductivity value of conductivity for the composite material. All samples show the high open circuit voltage value (1.05 V) at 650 °C. The Fourier transfer Infrared (FTIR) spectroscopy was employed to study the functional groups. The results shows that the synthesized novel BSMO, SCBO and their composites can be the efficient materials for the future low temperature SOFCs applications.