Influence of ZnO on Electrochemical and Physiochemical Properties of Lanthanum Strontium Cobalt Ferrite as Cathode for Intermediate Temperature Solid Oxide Fuel Cells

Abstract

This study investigates the impact of zinc oxide on the physical characteristics and electrochemical behavior of the LaSrCoFe (LSCF) cathode. Electrochemical impedance spectra in conjunction with the bode phase were used to optimize the amount of zinc oxide addition in the LSCF cathode. Brunauer-Emmett-Teller (BET) and thermal analysis were utilized to substantiate the electrochemical discovery that the LSCF: ZnO ratio yields rational oxygen reduction reaction and stoichiometric outcomes. Initial characterization, comprising of phase and bonding analyses, indicated that LSCF-ZnO was successfully synthesized at 800 ºC using an improved modified sol-gel technique. The addition of 5% zinc oxide to LSCF results in the lowest overall area-specific resistance (ASR) rating. The Bode phase implies that the addition of 5% zinc oxide to LSCF reduces the low-frequency impedance by 64.28%, indicating that the cathode experienced a greater oxygen reduction reaction. After the addition of 5% zinc oxide, a single LSCF-ZnO cell may function at temperatures as low as 650 °C, and the LSCF cathode power density is increased by 25.35%. The surface morphology of the LSCF-ZnO cathode reveals an overall particle size of less than 100 nm, and mapping analysis reveals a homogeneous distribution of ZnO over the cathode layer. Consequently, LSCF-ZnO demonstrated outstanding chemical compatibility between LSCF and ZnO, bonding characteristics, and electrochemical performance with the capacity to function at an intermediate temperature (600 °C – 800 °C).

Keywords

• active surface area
• intermediate temperature solid oxide fuel cell
• lscf-zinc oxide
• oxygen reduction reaction