Low Temperature Solid Oxide Fuel Cells Using LaGaO₃-based Oxide Electrolyte on Metal Support

Abstract

Solid oxide fuel cells (SOFCs) can directly convert the chemical energy of various fuels to electric power with unmatched energy conversion efficiency. The oxide ion conductivity of LaGaO3 doped with Sr and Mg (LSGM) is introduced and application of LSGM to low temperature SOFCs is explained. Power density at lower temperature was dramatically increased by application of LSGM film manufactured with laser ablation techniques. By application of a suitable buffer layer, the cell using LSGM thin film electrolyte had reasonable power density (0.2 W cm -2 ) at 773 K. Ce0.6Mn0.3Fe0.1O2 (CMF) oxide had high activity for the anodic reaction and insertion of a CMF layer much improved the maximum power density (0.17 W cm -2 at 673 K). Oxide anode consisting of Ce0.6Mn0.3Fe0.1O2 (CMF) _ La0.6Sr0.4Fe0.9Mn0.1O3 (LSFM) ( 12.5 : 87.5 wt%) enabled the use of dry hydrocarbon for fuel with almost no coke deposition.

Investigating the effect of rGO on microstructural and electrical properties of La0.9Sr0.1Ga0.8Mg0.2O3 in intermediate temperature SOFCs

“…[1][2][3][4][5][6][7][8] According to various reported studies, La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 3 (LSGM) has been considered as a promising electrolyte material for IT-SOFCs in the temperature range of 600-800 C owing to its higher ionic conductivity and stability over a broad range of O 2 partial pressures. The ionic conductivity of LSGM has been reported to be almost >0.005 S cm À1 at 500 C which is comparable to that of conventional yttria-stabilized zirconia (YSZ) which shows this ionic conductivity at 680 C. 9,10 In addition, LSGM possesses remarkable chemical compatibility with various perovskite electrode materials employed in SOFCs. Pure LaGaO 3 offers poor conductivity.…”

“…In the case of LSGM, impurity phases were increased with an increased ratio of La site/Ga site ions which is responsible for the reduction of the corresponding conductivity. 12 Ishihara et al 9 continued their studies to investigate the effect of a small amount of rare earth (neodymium (Nd), samarium (Sm), gadolinium (Gd), yttrium (Y), etc.) cations on the conductivity of the doped La site in LSGM and concluded that total conductivity was minimized and the magnitude relationship of conductivity was as follows: Nd 3+ > Sm 3+ > Gd 3+ > Y 3+ > Yb 3+ .…”

“…The ionic conductivity of LSGM has been reported to be almost >0.005 S cm −1 at 500 °C which is comparable to that of conventional yttria-stabilized zirconia (YSZ) which shows this ionic conductivity at 680 °C. 9,10 In addition, LSGM possesses remarkable chemical compatibility with various perovskite electrode materials employed in SOFCs. Pure LaGaO 3 offers poor conductivity.…”

“…Ishihara et al 9 investigated the doping and substitution of lanthanum gallate perovskites (LaGaO 3 ) with Sr and Mg and found that doping with Sr and Mg provides preferable results. They also reported that the proposed La 0.9 Sr 0.1 Ga 0.8 Mg 0.2 O 3 system (LSGM) exhibits remarkable conductivity and functions as a pure ionic conductor in the presence of large oxygen partial pressures ranging from 1 to 10 −15 Pa even at an elevated temperature (850 °C).…”

Modifying Grain Boundary Ionic/Electronic Transport in Nano-Sr- and Mg- Doped LaGaO3-δ by Sintering Variations

“…z E-mail: nhperry@illinois.edu perovskite electrodes. [7][8][9] Compared to well-established fluoritestructured yttria stabilized zirconia electrolytes, which have ionic transference numbers close to 1 across a wide range of oxygen partial pressures, 10 LSGM can exhibit non-negligible p-type electronic conductivity under oxidizing conditions. [11][12][13] In LaGaO 3 , the process of ionic compensation with oxygen vacancies (v •• O ) for Sr-and Mg-acceptor doping can be presented in Krӧger-Vink notation by:…”