U of Bristol leading nanoCAGE project to use new approach to hydrogen storage; potential 10x improvement
A low-density gas, hydrogen is challenging to store on-board a vehicle. Nanoporous materials (materials containing holes only a few nanometers in diameter) have been shown to adsorb hydrogen spontaneously so that it can be stored at exceedingly high densities under the right conditions.
However, storage of industrially relevant amounts of hydrogen (i.e. at levels approaching US Department of Energy technical targets) via adsorption in porous materials necessitates storage at very high pressures (typically >350 bar) or very low temperatures (e.g. 77 K / -196.15 °C).
The nanoCAGE project will challenge conventional approaches to the development of porous materials for storage of hydrogen which rely on simple adsorption of gases onto materials surfaces, and instead will change the mechanism by which the hydrogen is stored.
These new composites will be based on encapsulating existing nanoporous adsorbents in a continuous matrix of an active material that can control when gases are allowed in or out of the pores of the adsorbent.
The novel approach is that the active components will be triggered to undergo a reversible change in structure to induce controlled and reversible pore blocking to either allow or obstruct the movement of gases to or from the pores of the adsorbent, allowing these materials to act as a “nanocage” for gas molecules.
Another key innovation of the nanoCAGE project is the introduction of control over the trapping and release mechanisms using changes in external conditions such as light, heat or application of a magnetic field to change the structure of the active phase.
This approach, building upon Principal Investigator Dr. Valeska Ting’s expertise in hydrogen densification in nanoporous materials, could increase the amount of hydrogen stored in these materials at room temperature by ten times, making economical storage of hydrogen possible and providing a gateway to use of hydrogen for sustainable energy applications.
These composite materials could furthermore find application in many other fields of research (for example in carbon dioxide capture, controllable drug delivery and smart packaging) and will allow the PI to develop a new research area in active gas trapping composites.