Physical and sealing properties of BaO–Al2O3–SiO2–CaO–V2O5 glasses for solid oxide fuel cell applications

Abstract

In this study, the properties of BaO–Al 2 O 3 –SiO 2 (SAB) glasses incorporated with CaO and V 2 O 5 as the network modifier and additive, respectively, are evaluated. The electrical resistivities of the glasses decrease upon the addition of CaO but increase upon increasing their V 2 O 5 content because the V 5+ species lower the ionic mobility of the glasses. The addition of V 2 O 5 improves the wettability of the glasses on the Crofer 22 APU substrate, and thus, increases the fracture strength at the glass–Crofer 22 APU couple. Among the glasses evaluated, the SAB glass with a CaO content of 20 wt% and V 2 O 5 content of 2 wt% (SAB-Ca20V2) present excellent sealing properties because it adheres well to both the Zr 0·92 Y 0·08 O 2-δ (YSZ) and Crofer 22 APU substrates; no pores, cracks, or interfacial phases are present at the interfaces, confirming the good chemical and thermal compatibility of the glass–substrate pairs at high temperatures. After SAB-Ca20V2 is sealed on the Crofer 22 APU substrate at 850 °C, the leakage rate of the glass is low (<0.015 sccm⋅cm −1 at 800 °C for 200 h), indicating negligible deterioration of its sealing efficiency and revealing its remarkable potential for use in solid oxide fuel cell applications. • BaO–Al 2 O 3 –SiO 2 glasses added with CaO and V 2 O 5 were studied for SOFC applications. • Electrical resistivity declined with CaO addition, but escalated with V 2 O 5 content. • V 2 O 5 addition increased the fracture strength at the glass–Crofer 22 APU interface. • Excess CaO and V 2 O 5 ruined sealing/mechanical properties as bonded to Crofer22APU. • SAB-Ca20V2 glass showed trivial degradation at 800 °C displays its great potential for use in SOFCs.