Supercapacitors, which have started to garner quite a bit of research interest in the last few years, are a form of electrochemical capacitors capable of extremely high charge and discharge rates, long life cycles and unusually high power densities. Because of those attributes, supercaps, as they stood before UC-Riverside’s announcement, had the potential to wield dramatic influence over the future of electronics design. Today that potential seems even greater.
According to the team at UC-Riverside their research yielded a porous 3D carbon nanotube foam that has roughly double the power density and specific energy of today’s commercially available supercaps. Key to this increase in potential is the new material’s porous structure. Because of its microscopic hills and valleys the newly developed material can retain more electrolytes, which allows it to store more energy.
To construct their new wonder material researchers laced a vapor deposition of graphene and carbon nanotubes over a 3D nickel substrate. It was then coated with successive layers of hydrous ruthenium oxide (RuO2), which formed the material’s foamy, porous body and grounded the material’s graphene undercoat to its nickel body. With the graphene and carbon nanotubes fixed, researchers believed the graphene would both store current and absorb energy.
Their hunch proved to be right.
Over the course of an 8,000 cycle test researchers were able to verify that their foam electrode was not only capable of holding and absorbing energy without degradation but even became 6 percent more efficient after use.
“Besides high energy and power density, the designed graphene foam electrode system also demonstrates a facile and scalable binder-free technique for preparing high energy supercapacitor electrodes,” said graduate student Wei Wang. “These promising properties mean that this design could be ideal for future energy storage applications.”
While graphene-based supercapacitors have a long way to go before they displace traditional batteries their continued development means that one day cars, power grids and other power hungry arenas could perform their work with much higher efficiency.
Image Courtesy of UC-Riverside