Using freeze tape casting, Glacigen has demonstrated the engineering of unique microstructures in ceramic and metal substrates with the purpose of creating sheets of materials with anisotropic properties and graded compositions. A key purpose of Glacigen's research and development work is to demonstrate applications and refine material compositions for freeze tape cast materials and thereby reduce the risk and barriers for commercial partners to adopt such materials on their production lines. Applications for these materials can be found in batteries for electric vehicles and electric aircraft, solid-oxide fuel cells, thermal interface materials, and high temperature ceramic-metal interfaces.
Battery components are an area which stands to immediately benefit from the application of freeze tape casting. The microstructures produced by this process are advantageous for battery components including electrodes for rechargeable lithium ion batteries and gas diffusion layers in PEM fuel cells. Most importantly, the freeze tape casting process is functionally similar to the tape casting already widely used in the battery industry. Glacigen's funded research in this area includes a Phase I SBIR from the Department of Energy entitled "Advanced Manufacturing of Gas Diffusion Layers with Highly Engineered Porosity."
In the context of Glacigen's work, functionally graded materials refer to systems in which two different materials are joined based on the creation of a microstructure of one material and subsequent infiltration of that structure by a second material. This yields a sheet of material in which one face is substantially 100% material A, and the second face is substantially 100% material B. For example, a metal-ceramic functionally graded sheet provides a robust interface that terminates with ceramic on one face and metal on the other. Traditional metal-to-metal and ceramic-to-ceramic joining methods can then be used to bond either face of the functionally graded material to bulk parts, which will form a much thicker, stronger, and more damage-tolerant interface than can be achieved using traditional metal-to-ceramic joining methods. Glacigen's work in this area was launched with a Phase I SBIR from NASA entitled "Ceramic-Metal Interfaces by Functional Grading." A cross-section of the resulting material (alumina infiltrated with copper) is shown to the right. Application areas for this class of materials include hypersonic structures and propulsion, electric propulsion, and specialized heat transfer systems.
Glacigen is working to advance the state of the art in developing next generation solid oxide fuel cells (SOFCs) with exceptionally high performance and stability. A representative SOFC cell microstructure is shown at left. SOFCs are notable for their ability to reliably produce clean energy with very high efficiencies. Previously, their commercial potential has been limited by inadequate power densities and short lifetimes. Glacigen seeks to change this by uniquely incorporating concepts of additive manufacturing, synthesis of highly ordered micron-scale structures, and catalytic enhancement. Glacigen's work in this area was launched with a Phase I STTR from the Department of Energy entitled "Hybridization of Freeze Casting with Additive Manufacturing for Simplified Production of High Performance SOFCs." A critical innovation enabling this process is the demonstration of the capacity to co-sinter an entire SOFC in a single thermal treatment.
Glacigen's thermal interface materials are different from our other functionally graded materials, which also have advantageous thermal properties, in that the thermal interface materials are intended to be a superior alternative to existing thermal gap pads and greases, and to be used in the same applications as those existing solutions. In this role, the thermal interface material is applied as a removable pad between two elements, such as a battery and an associated heatsink. While the material offers the convenience and serviceability of a gap pad, it offers performance typical of greases - the best of both worlds. This behavior was achieved through the infiltration of a thermal grease into the microstructure. Initial work in this area was funded by a Phase I SBIR from the Navy entitled "High Performance Thermal Interface Material for Energy Storage Devices and Other Electronic Components." An example of the resulting polymer-based microstructure is shown at right.