https://phys.org/news/2018-07-laser-scribed-disordered-graphene-significantly-sodium-ion.html

The KAUST team led by Husam Alshareef has developed a process using a simple bench-top laser to make three-dimensional hard carbon directly on copper collectors without excessive temperatures or additional coating steps.

The team formed a polymer (urea-containing polyimide) sheet on copper and then exposed this sheet to strong laser light. By introducing nitrogen gas during the process, the team could replace some of the carbon atoms with nitrogen atoms, reaching an extremely high nitrogen level (13 atomic percent), which is unattainable by other techniques. Thus, the three-dimensional graphene was more conductive, had expanded atomic spacing, and was directly bonded to the copper current collectors, eliminating the need for additional processing steps.