High conductive (LiNaK)2CO3Ce0.85Sm0.15O2 electrolyte compositions for IT-SOFC applications. (10th August 2017)

• Record Type: Journal Article
• Authors: Khan, Ieeba; Asghar, Muhammad Imran; Lund, Peter D.; Basu, Suddhasatwa
• Is Part Of: International journal of hydrogen energy. Volume 42:Number 32(2017)
• Page Start: 20904
• Page End: 20909
• Publication Date: 2017-08-10
• Subjects: IT-SOFC -- Ternary carbonate–SDC electrolyte -- Carbonate loading -- Composite electrolytes; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2017.05.152
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Composite electrolytes of lithium, sodium, and potassium carbonate ((LiNaK)2 CO3 ), and samarium doped ceria (SDC) have been synthesized and the carbonate content optimized to study conductivity and its performance in intermediate-temperature solid oxide fuel cell (IT-SOFC). Electrolyte compositions of 20, 25, 30, 35, 45 wt% (LiNaK)2 CO3 –SDC are fabricated and the physical and electrochemical characterization is carried out using X-ray diffraction, scanning electron microscopy, electrochemical impedance spectroscope, and current–voltage measurements. The ionic conductivity of (LiNaK)2 CO3 –SDC electrolytes increases with increasing carbonate content. The best ionic conductivity is obtained for 45 wt% (LiNaK)2 CO3 –SDC composite electrolyte (0.72 S cm −1 at 600 °C) followed by the 35 wt% (LiNaK)2 CO3 –SDC composite electrolyte (0.55 S cm −1 at 600 °C). The symmetrical cell of the 35 wt% (LiNaK)2 CO3 –SDC composite electrolyte with lanthanum strontium cobalt ferrite (LSCF) electrode in air gives an area specific resistance of 0.155 Ω cm 2 at 500 °C. The maximum power density of the fuel cell using 35 wt% (LiNaK)2 CO3 –SDC composite electrolyte, composite NiO anode and composite LSCF cathode is found to be 801 mW cm −2 at 550 °C. Highlights: Optimisation of (LiNaK)2 CO3 content in SDC for stability and higher conductivity. 35wt% (LiNaK)2 CO3 –SDC electrolyte gives conductivity of 0.55 S cm −1 at 600 °C. Symmetrical cell (LiNaK)2 CO3 –SDC electrolytes and LSCF gives ASR of 0.155 Ω cm 2 . 801 mW cm −2 power density at 550 °C for IT-SOFC using 35wt% (LiNaK)2 CO3 –SDC electrolyte.