Boosting copper wire conductivity by a mere 5% can result in big motor efficiency gains and lighter weight components for electric vehicles as less copper is consumed. U.S. Pacific Northwest National Laboratory (PNNL) and General Motors researchers achieved these dual benefits by the addition of graphene flakes during the wire extrusion process.

The Shear Assisted Processing and Extrusion (ShAPE™) manufacturing platform developed at PNNL was used to produce the improved wire. The system applies shear force by rotating a metal or composite as it is pushed An ultra-high conductivity copper wire with graphene additives is 5% more conductive than annealed copper, the industry standard for motor applications. Source: Andrea Starr/PNNLthrough a die to create a new form. The scalable process generates internal heating by deforming the metal, which softens it and allows the formation of wires, tubes and bars. Any industry that uses copper to transmit electrical energy, including electric motors, generators and batteries, can benefit from the technology.

General Motors engineers verified the higher conductivity copper wire can be welded, brazed and formed in the same way as conventional copper wire, indicating seamless integration with existing motor manufacturing processes. The increase in conductivity was validated and greater ductility was also observed. Since the enhanced wire can be welded and subjected to other mechanical stresses with no degradation of performance, no specialized manufacturing methods are needed to assemble motors.