Fuel cells - Powder - Glass

Solid Oxide Fuel Cells (SOFC) are considered among the most promising methods for the efficient and environmentally-friendly production of energy. They convert chemical energy, generated from a combination of fuel (e.g. H2, natural gas) and oxidant (e.g. air) gases across an oxygen ion conducting ceramic, into electrical energy and heat. Due to harsh conditions that the SOFC operate in, such as high operating temperatures (about 650°C to 850°C) and aggressive environments within the cells (fuel, oxidant and humidity), all the materials used for this application must be carefully selected to ensure a safe, reliable and continuous operation of the SOFC. With a wide portfolio of glass and glass-ceramics with unique properties, SCHOTT Electronic Packaging has the ideal products for this demanding application.

Product Description

For generating power on a large scale, multiple SOFC are combined into high-performance cell stacks. The planar SOFC configuration, commonly used in stacks, provides a simple manufacturing process and high current densities. However, to prevent fuel-oxidant mixing, it also requires hermetic sealing of the metallic layers, serving as interconnects between the individual cells.

SCHOTT offers specially formulated glasses and glass-ceramics, which can withstand the harsh environments and high operating temperatures of SOFC, as sealing materials. They are from the system MO (M=Mg, Ca)-Al2O3-BaO-SiO2-B2O3.

Product Advantages

Glass and glass-ceramic sealants from SCHOTT Electronic Packaging stand out due to their exceptional longevity and robustness, particularly in aggressive environments. They offer the following advantages:

High temperature resistance
Chemical stability in reducing and oxidizing atmospheres
Closely matched CTE to all common materials used in SOFC
Viscosity curves adjusted to the particular operating temperature of different SOFC designs
Glass-ceramics and glass-ceramic composites with a stable structure and a residual amorphous phase providing them with self-healing properties.
Electrical resistance of > 2kΩ*cm at operating temperature
Variety of standard designs as well as customized products

Applications

SCHOTT provides a wide variety of glasses and glass-ceramics for cell and stack sealing of metallic and ceramic interconnects in all SOFC designs. The fields of application for SOFC are multiple. The high operating temperature allows SOFC to reform hydrocarbons internally, thus enabling the use of natural gas or reformed diesel as fuel. Therefore, SOFC are suitable candidates for application with heat engine energy recovery devices or combined heat and power systems.

Large market potentials have been forecast for Auxiliary Power Units (APUs) in long-haul trucks and buses for supplying air conditioning and other electrical services using the already available diesel fuel. Moreover, SOFC can serve as fuel-saving alternative in Remote Area Power Supplies (RAPS).

Technology

SCHOTT sealing glasses are made of special glass powders. For more information about our Glass Powder Technology, please click. In addition, SCHOTT has accumulated more than 50 years of experience in the field of glass-to-metal-sealing (GTMS) technology. This technology page provides detailed information.

Features / Specifications

Table I provides an overview of the physical properties of SCHOTT sealing materials, and Figure I illustrates their different viscosity behaviors.


Table 1 (click image to enlarge)	Figure 1 (click image to enlarge)

Forms of Supply and Product Packaging

All materials are available as finely ground powders and as dispensable pastes. Please contact us if you have special requests concerning supply and packaging.

Quality Assurance

All of our glass-to-metal sealing products are manufactured in our ISO 9001/14001 certified plant. Please refer to our quality and testing pages for more information.

Glass and Glass Ceramic Sealants for Solid Oxide Fuel Cells (Landshut address)