Not so hot. Materials scientist Keerti Kappagantula and her colleagues at DOE's Pacific Northwest National Laboratory discovered that graphene, single layers of the same graphite found in pencils, can enhance an important property of metals called the temperature coefficient of resistance.
This property explains why metal wires get hot when an electric current runs through them. Researchers want to reduce this resistance while enhancing a metal's ability to conduct electricity. For several years, they have been asking whether metal conductivity can be increased, especially at high temperatures, by adding other materials to it. And if yes, can these composites be viable at a commercial scale?
Now, they've demonstrated they can do just that, using a PNNL-patented advanced manufacturing platform called ShAPE.
When the research team added 18 parts per million of graphene to electrical-grade copper, the temperature coefficient of resistance decreased by 11 percent without decreasing electrical conductivity at room temperature. This is relevant for the manufacturing of electric vehicle motors, where an 11 percent increase in the electrical conductivity of copper wire winding translates into a 1 percent gain in motor efficiency.
The research team continues its work to customize the copper-graphene material and measure other essential properties, such as strength, fatigue, corrosion, and wear resistance, which are crucial to qualify such materials for industrial applications. Adding a small amount of solid carbon to copper boosts its conductivity (phys.org) b.