A research team led by the University of Liverpool, in UK, has discovered a new inorganic material with the lowest thermal conductivity ever recorded. This discovery paves the way for the development of new thermoelectric materials that will be fundamental for a sustainable society.
Published in the journal ‘Science’, this discovery represents a breakthrough in atomic-scale heat flow control, achieved through material design. Provides new fundamental insights into energy management. The new understanding will accelerate the development of new materials for convert waste heat into energy and for him efficient use of fuels.
The research team, led by Professor Matt Rosseinsky, from the University’s Department of Chemistry and Materials Innovation Factory, and Dr. Jon Alaria, from the University’s Department of Physics and the Stephenson Institute for Renewable Energy, designed and synthesized the new material in a way that combined two different arrangements of atoms that have been found to be reduce the speed at which heat travels by the structure of a solid.
They identified the mechanisms responsible for the reduction of heat transport in each of these two arrangements by measuring and modeling the thermal conductivities of two different structures, each of which contained one of the required arrangements.
Combining these mechanisms into a single material is difficult, because researchers have to exactly control the arrangement of the atoms in it. Intuitively, scientists would expect to obtain an average of the physical properties of the two components. By choosing favorable chemical interfaces between each of these different atomic arrangements, the team experimentally synthesized a material that combines both.
This new material, with two arrangements combined, has a much lower thermal conductivity than any of the parent materials with a single arrangement. This unexpected result shows the synergistic effect of chemical control of atomic locations in the structure, and it is the reason why the properties of the complete structure are superior to those of the two individual parts.
If we take the thermal conductivity of steel as 1, then a titanium bar is 0.1, water and a building brick is 0.01, the new material is 0.001, and air is 0.0005.
Approximately 70% of all the energy generated in the world is wasted as heat. Low thermal conductivity materials are essential to reduce and take advantage of this waste. The development of new and more efficient thermoelectric materials capable of converting heat into electricity is seen as a key source of clean energy.
Professor Matt Rosseinsky notes that “the discovered material has the lowest thermal conductivity of any inorganic solid and is almost as bad a conductor of heat as the air itselfHe stresses that “the implications of this discovery are important, both for fundamental scientific understanding and for practical applications in thermoelectric devices that collect waste heat and as thermal barrier coatings for more efficient gas turbines.”
For his part, Dr. Jon Alaria assures that “this exciting finding is that it is possible to improve the property of a material using concepts of complementary physics and a suitable atomistic interface. Beyond heat transport,” he explains, “this strategy could applied to other important fundamental physical properties, such as magnetism and superconductivity, which would lead to less energy computation and more efficient transport of electricity. ”