Development of New Fast Oxide Ion Conductor and Application for Intermediate Temperature Solid Oxide Fuel Cells

Abstract

Solid Oxide Fuel Cell (SOFC) show great promise as new power generators with high efficiency. Decreasing the operating temperature is critically required for the further development of SOFC. This review introduces that oxide ion conductivity in the perovskite oxide of LaGaO 3 , which was found by our group. LaGaO 3 doped with La and Mg exhibits the high oxide ion conductivity over a wide P O2 range; the value is higher than that of Y 2 O 3 -stabilized ZrO 2 by an order of magnitude. When LaGaO 3 -based oxide was used as the electrolyte of SOFC, the power density could be improved greatly, in particular over the low-temperature range. In this study, the power generating property of LSGM using a thin film of LaGaO 3 is also introduced. The maximum power density of the cell using LaGaO 3 -based oxide is as high as 0.6 W cm À2 at 773 K. This suggests that SOFC could be operable at temperature lower than 773 K.

Rare earth elements based oxide ion conductors

“…Nevertheless, interstitial oxide ion conduction has been found to exist in apatite, scheelite, mellite, and β-SnWO 4 -structured systems with excess oxide ions, which exhibit high interstitial oxide ion conductivities. 31,[42][43][44][45][46] The Arrhenius plots of the conductivities of oxide ion conductors with various structures are shown in Fig. 3.…”

Efeito da co-dopagem com Pr e Mn nas propriedades elétricas de Sr-LaAlO3

“…Dessa forma, intensificou-se a busca por novos materiais com condutividade iônica superior à da zircônia estabilizada com ítria e foi estabelecido que um estudo sobre a estrutura dos materiais seria um dos possíveis caminhos [14]. Neste contexto, eletrólitos baseados em óxidos do tipo perovskita (ABO 3 ) receberam muita atenção nos últimos anos como uma alternativa aos eletrólitos baseados em zircônia [15][16], pois esta estrutura cristalina única é muito tolerante à vários tamanhos de cátions em ambas as subredes catiônicas A e B. Assim, cátions aliovalentes podem ser introduzidos em ambos os sítios das sub-redes e, por conseqüência vacâncias de oxigênio são geradas para garantir a neutralidade elétrica. Portanto, óxidos tipo perovskita oferecem numerosas vantagens, especialmente pela estabilidade da estrutura, a variedade de elementos que podem ser acomodados na rede cristalina e a facilidade com que vacâncias de oxigênio podem ser produzidas através da substituição parcial dos cátions dos sítios A e/ou B com cátions de valência mais baixa [17][18].…”

Electrophretic Deposition of LDC/LSGM/LDC Tri-layers on NiO-YSZ for Anode-supported SOFC

“…The oxide ionic conductivity of LaGaO 3 can be further improved by partially substituting the La and Ga ions with Sr and Mg, respectively. The simultaneous doping of the Sr and Mg ions into LaGaO 3 is denoted as LSGM; the optimized composition is well known as La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 3-d (specifically denoted as LSGM8282) which has the highest oxide ionic conductivity among the LaGaO 3 -based oxides [1][2][3]. LSGM has a high oxygen conductivity at low temperatures; however, it reacts with the electrode materials during operation.…”