Scientists at a government research institute have discovered an unusual way heat moves through a crystal material, opening possibilities for converting industrial waste heat into electricity. The Ministry of Science and Technology announced the finding, which could benefit power plants, steel and cement factories, vehicle manufacturers, data centres and battery systems.
Researchers at the Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Bengaluru, an autonomous institution under the Department of Science and Technology, studied a copper-based material called thallium copper selenide (TlCu5Se3). Their work, led by Prof. Kanishka Biswas and published in the journal Science Advances, shows how this material transports heat in an unexpected wave-like pattern rather than through the particle-like movement normally seen in crystals.
How the discovery works
Most heat in solid crystals travels through particles called phonons, which move like individual objects across the material. In this new material, however, the complex crystal structure traps copper atoms in confined spaces, preventing them from moving freely. This confinement creates strong irregularities in atomic vibrations. As a result, heat travels not as distinct particles but as waves that tunnel between different vibrational states, similar to how light behaves as both particle and wave.
The confined copper dynamics suppress heat transport while keeping the material structurally stable, avoiding the instability problems that occur in conventional superionic materials. The research team performed computer simulations and theoretical calculations to understand this behaviour. The material achieved a thermoelectric efficiency rating (called zT) of 1.7, among the highest recorded for similar copper chalcogenide compounds. Higher zT values mean better conversion of waste heat to usable electricity.
What this means for you
This discovery could make industrial waste heat recovery practical and efficient. Factories, power stations and even vehicle exhaust systems generate enormous amounts of unused heat. If this material can be developed for commercial use, it could convert that wasted energy into electricity, reducing both energy costs and environmental impact. The technology may eventually appear in data centres managing server heat and in electric vehicle battery systems requiring thermal management.