Electrochemical properties of ceria-based intermediate temperature solid oxide fuel cell using microwave heat-treated La0.1Sr0.9Co0.8Fe0.2O3−δ as a cathode

• Published in: Journal of power sources 2012-12, Vol.220, p.377-382
• Main Authors: Choi, M.-B., Lee, K.-T., Yoon, H.-S., Jeon, S.-Y., Wachsman, E.D., Song, S.-J.
• Format: Article
• Language: English
• Subjects: Air conditioning. Ventilation; Applied sciences; Cathode; Chemical diffusion coefficient; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Fuel cells; Heating, air conditioning and ventilation; IT-SOFC; Microwave sintering; Surface exchange coefficient; Techniques, equipment. Control. Metering
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2012.07.122

The temperature dependence of the chemical diffusion coefficient and the surface exchange coefficient of LSCF1982 is successfully determined from the D.C. conductivity relaxation in the temperature range of 500 ≤ T/°C ≤ 700 and an oxygen partial pressure of 0.21 atm. The kinetic values of chemical diffusion coefficient (D˜) and surface exchange coefficient (k) are 1.85 × 10−5 cm2 s−1 and 2.42 × 10−4 cm s−1 at 650 °C, respectively. The electrochemical properties of La0.1Sr0.9Co0.8Fe0.2O3−δ (LSCF1982) as a cathode for ceria based IT-SOFC are successfully characterized by I–V performance measurement and electrochemical impedance spectroscopy (EIS) in terms of cathode microstructure effects by using microwave heat treatment. The cell with microwave heat-treated cathode shows the higher performance than conventional heat treated cathode. At 650 °C the open circuit potential (OCP) and maximum power density are respectively 0.753 V and 1.79 W cm−2 under 150 sccm of wet hydrogen and air gas flow conditions, and the ohmic and electrode area specific resistance (ASR) are 0.037 and 0.014 Ω cm2, respectively. [Display omitted] Performance of button cell as a function of temperatures under 150 sccm wet hydrogen and air gas. ▸ New promising cathode material of IT-SOFC was suggested. ▸ Cathode microstructure effects by microwave heating were reported. ▸ OCP and maximum power density were respectively 0.753 V and 1.79 W cm−2 at 650 °C.