Effect of Al2O3 addition on the non-isothermal crystallization kinetics and long-term stability of BCABS sealing glass for IT-SOFCs

Abstract

Owing to adjustable thermal expansion performance, BaO-CaO-Al 2 O 3-B 2 O 3-SiO 2 (BCABS) glass has a promising commercialization prospect for intermediate temperature-solid oxide fuel cells (IT-SOFCs) sealing. Herein, Al 2 O 3 with two different contents was added into the same glass formulation, referred to as A and B glass, respectively. In terms of the non-isothermal crystallization kinetic behavior, the effect of Al 2 O 3 as the unique intermediate was innovatively studied on the long-term performance of BCABS sealing glass. After the heat treatment at 1023 K for 100 h, the change of the network structure and the expansion coefficient of the glass were characterized. The results showed that the addition of Al 2 O 3 as a network forming body could enhance the structure of glass, and increase the activation energy for glass transition, which could effectively inhibit the crystallization ability of sealing glass. Therefore, the B glass with the higher Al 2 O 3 content showed the better long-term sealing ability, which was greatly beneficial for IT-SOFCs sealing. Keywords: intermediate temperature-solid oxide fuel cell (IT-SOFC); BaO-CaO-Al 2 O 3-B 2 O 3-SiO 2 (BCABS) sealing glass; Al 2 O 3 ; non-isothermal crystallization kinetics; long-term stability * Corresponding authors. [3]. According to the stacking design and fabrication, the planar type and sealless tubular design for IT-SOFCs have been given much favor by researchers at present [4]. The sealless tubular design has a relatively long current path through the cell, which would result in the great resistive loss. As compared to the tubular design, the planar-type IT-SOFCs could provide the higher power density due to the effective planar structure that consists of the repeated unit by the combination of anode-electrolyte-cathode structure and interconnector [5]. The suitable sealing materials must be required to prevent fuel leakage and air mixing at the high operating temperature to create a hermetic, rugged, stable, and safe stack, which is the urgent

Glass–Zirconia Composites as Seals for Solid Oxide Cells: Preparation, Properties, and Stability over Repeated Thermal Cycles

“…Such composites also have a self-healing character, as the glass matrix remains viscous. Many different types of reinforcement have been studied to date, including: Al 2 O 3 [ 17 , 18 , 19 ], ZnO [ 20 , 21 ], Nb 2 O 5 [ 22 ], V 2 O 5 [ 21 ], AlN [ 23 ], Y 2 O 3 [ 24 ], Cr 2 O 3 [ 25 ], MgO [ 26 , 27 ], Bi 2 O 3 [ 28 , 29 ], BaO [ 30 ], La 2 O 3 [ 31 ], mica [ 32 , 33 ], and ZrO 2 . ZrO 2 reinforcement is the most interesting one for the authors because it is seen as an additive stimulating crystallization of the seal, which is often desirable for enhancing the mechanical properties of the joint, depending on the SOC stack design.…”

The development of 3D technology for the creation of glass sealants for tubular oxide fuel cells

“…Therefore, numerous studies published in recent decades are devoted to developing a glass sealant composition that meets the requirements of chemical and thermal compatibility with SOFC materials. To date, many suitable compositions have been developed and tested under operating conditions 1–6 …”

“…To date, many suitable compositions have been developed and tested under operating conditions. [1][2][3][4][5][6] At the same time, technological approaches to sealant molding are developed poorly, but this step is essential to commercialize glass sealants, especially those applied for tubular SOFC design. Slip-casting, screen printing, and 3D printing are the most suitable methods for the large-scale production of glass sealants.…”

Additive manufacturing of thin electrolyte layers via inkjet printing of highly-stable ceramic inks

“…Solid oxide fuel cells (SOFCs) are a type of highly efficient and pollution free energy conversion devices with solid-state structures [9,10]. A planar SOFC single cell generally consists of three key layered structures, such as cathode, electrolyte, and anode layers.…”