Cost-effective suspension formulation for flexible TiB2 tapes

Abstract

The manufacturing of ultra-high temperature ceramic materials has significantly advanced over recent years, allowing for the development of new microstructures, architectures, shapes, and geometries to explore new properties and applications for these materials beyond aerospace. For example, titanium diboride (TiB₂) exhibits high electrical and thermal conductivity that could satisfy the needs of battery applications by tailoring its geometry, microstructure, and architecture. In this work, aqueous tape casting of TiB₂ has been investigated. Zeta potential measurements and suspension rheology were used to understand the role of dispersant, binder, and plasticizer in the suspension and their interaction with the surface chemistry of the TiB₂ particles to develop a stable, homogenous suspension, with minimum additive amounts (0%–2 wt%). Homogeneous, flexible, and strong TiB₂ tapes were prepared using suspensions with 30 vol% solids and characterized to compare different compositions, mixing methods, and thicknesses. The characterization shows the tailoring of the properties as a function of the controlled suspension formulation with a minimum amount of additives. Green tapes with 2 wt% dispersants, 1 wt% binder, and 2 wt% plasticizers had similar microstructure to those with half the plasticizer but quintuple Young's modulus (1.96 GPa). The effect on other relevant properties is also discussed.