High-Entropy Alloys for Hydrogen Storage
High-Entropy-Alloys are an emerging class of advanced materials that have attracted considerable attention in recent years due to their promising properties for a wide range of applications: excellent mechanical properties at high temperatures, magnetism, energy storage and conversion, and corrosion protection. High-Entropy-Alloys consist of at least five metallic elements alloyed in nearly equimolar proportions, and it is believed that the high configurational entropy in this multi-element alloy plays a crucial role in stabilizing the material in a single phase. Since every metal element of the periodic table could potentially be alloyed in various concentrations, this broad design freedom opens up a vast field. In the context of hydrogen storage, it has been shown that the thermodynamic properties of potential storage materials can be tailored by changing the composition and concentration of the alloying elements.
The Felderhoff group has been conducting research for many years on the development of novel High-Entropy Alloys (HEAs), with a focus on integrating these materials into practical technical applications. Their work includes:
- Lightweight HEAs for use in mobile applications,
- HEAs capable of storing hydrogen at high pressures for hydrogen compression,
- HEAs with optimized hydrogen cycling behavior for the design of efficient storage tanks, and
- HEAs operate as reversible hydrogen storage materials across both low and high temperatures for various gas separation and purification processes.
Another focus in our group is the development of simple and sustainable synthesis methods for HEAs in mechanochemical processes. Conventionally, alloys are synthesized in melting procedures, which require high temperatures. In contrast, our group is working on various ball-milling techniques that enable HEA synthesis at ambient temperature.