About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advanced Materials for Energy Conversion and Storage 2026
|
| Presentation Title |
Cation Engineering of Water Intercalation in Layered Manganese Dioxide for Low-Temperature Thermal Energy Storage |
| Author(s) |
Hiroki Yoshisako, Norihiko L Okamoto, Kazuya Tanaka, Tetsu Ichitsubo |
| On-Site Speaker (Planned) |
Hiroki Yoshisako |
| Abstract Scope |
Layered manganese dioxide containing K+ between MnO2 layers (δ-K0.33MnO2‧nH2O) is known to accommodate H2O molecules in the interlayer spaces for phase stabilization. These H2O molecules can be reversibly extracted and inserted around 130°C through a rapid (de)intercalation mechanism. Our research group has found that thermal energy exceeding the enthalpy of sublimation of H2O molecules (51 kJ per mol-H2O at 25°C) can be stored and released through this process, demonstrating an energy density over 1000 MJ m-3. Therefore, δ-MnO2 is a promising material for storing low-temperature (100–200°C) waste heat, including solar thermal heat. This study investigates how interlayer cation species influence the properties of thermal energy storage of δ-MnO2. Preliminary results suggest that the nature of the interlayer cation significantly affects both the thermal energy density and the (de)intercalation kinetics. Ongoing work aims to clarify the underlying mechanisms, particularly focusing on the hydration behavior and ion–water interactions. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Energy Conversion and Storage, Environmental Effects, Phase Transformations |