Glass sealing material as well as preparation and use methods thereof

Abstract

The invention relates to a glass sealing material as well as preparation and use methods thereof. The glass sealing material comprises the following raw material components at a molar ratio: 0-10 of B2O3, 0-5 of Al2O3, 25-60 of SiO2, 10-25 of CaO, 10-25 of SrO and 5-25 of Ca2O3. According to the invention, a Ga element is added in the glass sealing material so as to form a non-proliferation layer, thus effectively reducing the proliferation of Cr ions in a Cr-containing stainless steel alloy connection pole toward the sealing glass and significantly improving the high temperature chemical stability of sealing microcrystal glass; preparation raw materials are simple and available, and process is stable; and a reverse glass network structure in which SiO2 is used as a main body is obtained,cost is low, and process is simple and practicable, thereby achieving the conditions of practicality and industrialization.

Description

technical field [0001] The invention belongs to the field of solid oxide fuel cells, and in particular relates to a glass-ceramic sealing material with high-temperature chemical stability and its preparation and use. Background technique [0002] Solid oxide fuel cell (SOFC) adopts solid oxide (ceramic) electrolyte, operates at high temperature, has high power generation efficiency, low material cost, and is compatible with various fuels (such as methane, gas, methanol, alcohol, liquefied petroleum gas, etc. )Etc. However, the main problem facing the development of SOFC is how to effectively isolate and seal the fuel gas and oxidant gas at high temperatures. Due to the high operating temperature of the battery (700-750°C), the selection of suitable sealing materials and sealing technologies has become the key to restricting the development of planar SOFCs. In order to solve the problem of sealing failure between sealing materials and Cr-containing stainless steels, researc...

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Problems solved by technology

However, how to pass containing B 2 o 3 The high-temperature stability of the material remains an open question

[0004] Due to the thermal expansion coefficient mismatch between the sealing material and other components (such as sealing glass (11~13) ×10 -6 / K, chromium-containing stainless steel alloy connector ~13×10 -6 / K) leads to the generation of thermal stress, and then induces the initiation and expansion of cracks, resulting in the final failure of the seal. A lot of research at home and abroad has invested a lot of energy in the development of self-healing sealing materials that can maintain the glassy state for a long time at high temperatures, trying to pass Viscous flow of the glass phase relieves thermal stress accumulated at the sealing interface

However, the network ligand ions (such as group IIA) used to improve the viscosity of the sealing glass react easily with the Cr-containing alloy linker at the working temperature of the SOFC, forming such as BaCrO 4 , SrCrO 4 and CaCrO 4 etc. have extremely high coefficient of thermal expansion (18~20×10 -6 / K), which again causes the thermal expansion coefficient mismatch with other components of the sealing interface, destroys the bonding force of the seal, and seriously restricts the service life of the sealing material and SOFC, especially the stability in the thermal cycle process.

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