An investigation on the microstructural and electrical properties of La0.85DxSr0.15–xGa0.8Mg0.2O2.825 (D = Ba and Ca) electrolytes in solid oxide fuel cells. Issue 16 (November 2018)

• Record Type: Journal Article
• Authors: Wu, Yu-Chuan; Rao, Chen-Ruei
• Is Part Of: Ceramics international. Volume 44:Issue 16(2018)
• Page Start: 19706
• Page End: 19717
• Publication Date: 2018-11
• Subjects: Solid oxide fuel cell -- Electrolyte -- La1−xSrxGa1−yMgyO3−δ (LSGM) -- Impedance, Solid-state reaction -- LaGaO3; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2018.07.224
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: La0.85 D x Sr0.15– x Ga0.8 Mg0.2 O2.825 ( D = Ba and Ca, x = 0, 0.01, 0.03, 0.05, and 0.07) electrolytes were synthesized using a solid-state reaction method, calcined at 1400 °C for 5 h, and sintered at 1400 °C for 5 h. The microstructures, electrical properties, and cell performances of the electrolytes and fuel cells were analyzed by X-ray diffraction, scanning electron microscopy, impedance analysis, and electrochemical analysis. La0.85 Ba x Sr0.15– x Ga0.8 Mg0.2 O2.825 (LBSGM) and La0.85 Ca x Sr0.15– x Ga0.8 Mg0.2 O2.825 (LCSGM) exhibit a dense structure and a cubic perovskite phase. Further, they contain small amounts of a secondary phase. The lattice constants of LBSGM and LCSGM are 0.3913–0.3914 nm and 0.3906–0.3909 nm, respectively. The average grain size of the sample increases with increasing Ba 2+ or Ca 2+ content. The conductivity of LCSGM (0.197–0.174 S/cm) is usually higher than that of LBSGM (0.181–0.162 S/cm) at 800 °C. The cells with La0.85 Sr0.15 Ga0.8 Mg0.2 O2.825 and La0.85 Ca0.03 Sr0.12 Ga0.8 Mg0.2 O2.825 electrolytes exhibit high open-circuit voltages and maximum power densities of 0.96 V and 542 mW/cm 2 and 0.94 V and 567 mW/cm 2, respectively, at 800 °C.