A British science research team has recently developed a new crystalline material for thermal energy storage, which not only stores 4 months and above solar thermal energy under room temperature, but is also capable of releasing thermal energy according to various needs. The research team believes that this material, which is able to store thermal energy for a prolonged period, will become a potential help in battling the imminent winter season.
This material developed by the Lancaster University is primarily based on the rising star of the porous material sector: metal-organic framework (MOF), which is a carbon-based 3D framework assembled and formed with inorganic metals and organic ligands, and contains the porous property as well as a high specific surface area that absorbs substantial amount of gas, or produces composite materials by combining other small molecules, thus different physics and chemistry properties are formed by various material compositions.
The MOF material studied by the research team is filled with azobenzene, which contains excellent light-harvesting property according to the research team, and can be used as the molecular machine of MOF, which in other words acts as a switch that alters the shape when receiving external stimulations such as light and heat.
The experiment showed that the azobenzene within the MOF will result in a strained configuration for the inside of the material if exposed under UV light, which is somewhat similar to the elastic potential energy of springs that also stores energy through shape changes. The research team points out that reduced MOF pores can also capture azobenzene molecules, and store thermal energy for a long duration. To execute the “on and off” motion, a simple application of external thermal energy will suffice.
John Griffin, senior lecturer in materials chemistry at Lancaster University and the host of the particular project, commented that MOF bears resemblances to phase-change materials, and can be used as an electric hot water bag or a hand warmer, where the only difference is that it receives energy from irradiation without the need of charging, so there will not be any loss of energy during both the storage and release of thermal energy. Griffin commented that he hopes to see further study in the future pertaining to the production of materials that are able to store other energy.
Further testing indicates that the specific material is capable of storing at least 4 months’ worth of energy, which exceeds far from the several hours and days of other photosensitive materials, and can be applied on the cross season thermal energy storage technology. In addition, the MOF material possesses a higher degree of stability due to it being a non-liquid fuel, and can be further developed into a coating or independent equipment that will expand its application range.
The research team believes that this specific material can be used in heating systems in remote areas or regions that are far from the power grid, as well as an eco-friendly heating option for residence and offices. As for the heating methods, one can try spreading it on the external wall of a building, and the windshield of a vehicle, which in a way has transformed the material into a necessary companion for daily lives.
(Cover photo source: pixabay)