Discovery of a new inorganic material with the lowest thermal conductivity ever reported
A collaborative research team, led by the University of Liverpool, has discovered a new inorganic material with the lowest thermal conductivity ever reported. This discovery paves the way for the development of new thermoelectric materials that will be essential for a sustainable society.
Reported in the newspaper Science, this discovery represents a breakthrough in the control of heat flow at the atomic scale, achieved through materials design. It offers new fundamental perspectives on energy management. The new understanding will accelerate the development of new materials to convert waste heat into electricity and for 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 so that it combines two different arrangements. atoms that each slow down the rate at which heat moves through the structure of a solid.
They identified the mechanisms responsible for reducing 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, as researchers have to control exactly how the atoms are arranged in it. Intuitively, scientists would expect to get 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 them both (represented by the yellow and blue plates in the image).
This new material, with two arrangements combined, has a much lower thermal conductivity than either 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 is the reason why the properties of the whole structure are superior to those of the two individual parts.
If we take the thermal conductivity of steel to be 1, then a titanium bar is 0.1, water and a building brick are 0.01, the new material is 0.001, and air is 0.0005.
About 70 percent of all the energy produced in the world is wasted as heat. Materials with low thermal conductivity are essential to reduce and exploit this waste. The development of new, more efficient thermoelectric materials capable of converting heat into electricity is seen as a key source of clean energy.
Professor Matt Rosseinsky said: “The material we have discovered has the lowest thermal conductivity of all inorganic solids and is almost as bad a heat conductor as air itself.
“The implications of this discovery are important, both for fundamental scientific understanding and for practical applications in thermoelectric devices that recover waste heat and as thermal barrier coatings for more efficient gas turbines. “
Dr Jon Alaria said: “The exciting discovery of this study is that it is possible to improve the properties of a material using complementary physics concepts and an appropriate atomistic interface. Beyond heat transport, this strategy could be applied to other important fundamental physical properties such as magnetism and superconductivity, leading to low power computation and more efficient transport of electricity.
Reference: “Low thermal conductivity in a modular inorganic material with bonding anisotropy and mismatch” by Quinn D. Gibson, Tianqi Zhao, Luke M. Daniels, Helen C. Walker, Ramzy Daou, Sylvie Hébert, Marco Zanella, Matthew S. Dyer, John B. Claridge, Ben Slater, Michael W. Gaultois, Furio Corà, Jonathan Alaria and Matthew J. Rosseinsky, July 15, 2021, Science.
DOI: 10.1126 / science.abh1619
The research team includes researchers from the University of Liverpool Leverhulme Research Center for the Design of Functional Materials, University College London, ISIS Rutherford Appleton Laboratory and CRISMAT Laboratory.
This project received funding from the Engineering and Physical Science Research Council (EPSRC grant EP / N004884), the Leverhulme Trust and the Royal Society.