“We have developed a ‘designer carbon’ that is both versatile and controllable,” said Zhenan Bao, the senior author of the study and a professor of chemical engineering at Stanford. “Our study shows that this material has exceptional energy-storage capacity, enabling unprecedented performance in lithium-sulfur batteries and supercapacitors.”
The new material is a dramatic improvement over conventional activated carbon that is made by burning coconut shells at high temperatures and then chemically treating them. That process creates nanosized holes that increase the surface area of the carbon, allowing it to catalyze more chemical reactions and store more electrical charges.
But activated carbon has drawbacks, Bao said. For example, there is little interconnectivity between the pores, which limits their ability to transport electricity.
Instead of using coconut shells, Bao and her colleagues developed a new way to synthesise high-quality carbon using inexpensive – and uncontaminated – chemicals and polymers that form an interconnected, three-dimensional framework that’s ideal for conducting electricity.
“This framework also contains organic molecules and functional atoms, such as nitrogen, which allow us to tune the electronic properties of the carbon.”