Chemical compatibility of Sr₂MgMoO_6−δ with representative electrolyte materials and interlayer materials for solid oxide fuel cells

Abstract

Sr 2 MgMoO 6¹¤ (SMM) is one of promising anode materials for direct internal reforming solid oxide fuel cells as its excellent performance has been demonstrated. However, it is necessary to be chemically compatible with the electrolyte material to realize the original performance. In this study, we investigate chemical compatibility between SMM and typical electrolyte materials (8% mol Y 2 O 3 92% mol ZrO 2 ; YSZ, 10% mol Sc 2 O 3 1% mol CeO 2 89% mol ZrO 2 ; ScSZ, La 0.9 Sr 0.1 Ga 0.8 Mg 0.2 O 3¹¤ ; LSGM) and anode interlayer materials (Gd 0.1 Ce 0.9 O 2¹¤ ; GDC, Ce 0.8 La 0.2 O 2¹¤ ; LDC) under conditions for preparing SMM electrode and operation. SMM formed a reaction layer with all of the typical electrolyte materials studied. LDC was the only material for the interlayer that maintains chemical compatibility with SMM, though it forms the reaction layer with YSZ and ScSZ. From these results, this study clarifies that LSGM and LDC should be used as electrolyte and interlayer, respectively, when SMM is used as the anode.

Recent Progress in the Design, Characterisation and Application of LaAlO3- and LaGaO3-Based Solid Oxide Fuel Cell Electrolytes

“…Good chemical compatibility between LSGM and anodes with a double perovskite structure was shown for: La 0.9 Sr 0.1 Ga 0.8 Mg 0.2 O 3−δ and Sr 2 TiMoO 6−δ after calcining the samples at 1000 • C for 10 h in an atmosphere of 5% H 2 /Ar [160], La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 3−δ and Sr 2 Fe 1.5 Mo 0.5 O 6−δ after heat treatment at 1200 • C for 24 h in air [161], La 0.88 Sr 0.12 Ga 0.82 Mg 0.18 O 3−δ with Sr 2 NiMoO 6−δ at 1000 • C for 20 h [162,163] and Sr 2 Ni 0.75 Mg 0.25 MoO 6−δ at 1100 • C for 20 h [164] and at 1250 • C for 2 h [163]. The formation of secondary phases between LSGM and double perovskite anodes was observed for La 0.9 Sr 0.1 Ga 0.8 Mg 0.2 O 3−δ and Sr 2 MgMoO 6−δ after calcining at 1100 • C [165], for La 0.88 Sr 0.12 Ga 0.82 Mg 0.18 O 3−δ and Sr 2 ZnMoO 6 at 1000 • C for 20 h [166] and for La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 3−δ at 1300 • C for 10 h with Sr 2 Ni 0.7 Mg 0.3 MoO 6−δ [167] and, after heat treatment at 1200 • C for 24 h, with Sr 2 CoMoO 6−δ [161], Sr 2 NiMoO 6−δ [161] and Sr 2 MgMoO 6−δ [168].…”

“…The chemical compatibility of La 1−x Sr x Ga 1−y Mg y O 3−δ was investigated with oxide materials used in SOFCs, cathodes [141][142][143][144][145][146][147][148][149][150][151][152] and anodes [153][154][155][156][157][158][159][160][161][162][163][164][165][166][167]: this is presented in the corresponding reviews [28,56,153].…”

Undoped Sr2MMoO6 Double Perovskite Molybdates (M = Ni, Mg, Fe) as Promising Anode Materials for Solid Oxide Fuel Cells

“…As Sr 2 NiMoO 6-δ , Sr 2 MgMoO 6-δ can be obtained through different synthesis methods: solid state synthesis [ 19 , 97 , 98 , 99 , 100 , 101 , 102 , 103 ], solution methods (including sol-gel technology using citric acid [ 24 , 37 , 45 , 72 , 104 , 105 , 106 , 107 ] and EDTA [ 20 , 76 , 77 , 108 , 109 ]), the combustion method using glycine as a fuel and complexing agent [ 110 , 111 ] and the freeze-drying method [ 88 , 108 ]. The main disadvantage of this compound is its non-single phase after synthesis in air ( Figure 8 ).…”

“…The thermal compatibility of Sr 2 MgMoO 6-δ with an LSGM electrolyte was studied in [ 99 ]. It was found that an insignificant interaction between these components begins after annealing at 700 °C ( Figure 9 ).…”

“… XRD patterns recorded for mixtures of Sr 2 MgMoO 6-δ and LSGM calcined in air at different temperatures. Reproduced with permission [ 99 ]. Copyright 2018, The Ceramic Society of Japan.…”