About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advanced Materials for Energy Conversion and Storage 2026
|
| Presentation Title |
Impact of Tunnel Chemistry on Ion Transport, Lattice Dynamics and Thermodynamic Stability in Hollandite-type Materials |
| Author(s) |
Nakeshma Cassell, Kyle Brinkman |
| On-Site Speaker (Planned) |
Nakeshma Cassell |
| Abstract Scope |
Titanate-based hollandite-type materials, with one-dimensional tunnels and exceptional compositional tunability, are promising candidates for solid-state ionic conductors in next-generation energy systems. While their crystal chemistry is well established, the effects of tunnel occupancy and A-site cation identity on thermodynamic stability and ionic transport remain poorly understood. In this work, we investigate a series of hollandite compositions to evaluate how A-site cation size and tunnel filling influence structural, thermodynamic, and functional behavior. Drop solution calorimetry is used to determine enthalpies of formation from binary oxides, providing insight into composition-dependent stability. Low-temperature heat capacity measurements (2–300 K) probe lattice dynamics and entropy contributions. Electrochemical impedance spectroscopy evaluates ionic conductivity and activation energy as a function of composition and tunnel occupancy. Together, these results establish a link between tunnel chemistry and functional performance, offering guidance for the design of hollandite materials as solid-state electrolytes in advanced energy storage and conversion technologies. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Ceramics, Energy Conversion and Storage, High-Temperature Materials |