SBIR Phase I:Mesoporous Graphene Electrodes for Supercapacitors

This Small Business Innovation Research Phase I Project will develop high capacitance, low resistance graphene electrodes for supercapacitors to achieve high power and energy densities. One of the major technical barriers to high performance supercapacitors is low specific capacitance of the currently used activated carbon electrodes. This barrier is primarily due to poor access to the activated carbon surface area by an electrolyte: a substantial fraction of the surface area is in the form of micropores (< 2nm diameter) and consequently inaccessible to ion migration and therefore, unable to contribute to energy storage. This difficulty can be ameliorated by replacing microporous activated carbon with graphene, a one-atom-thick, conductive allotrope of carbon with a rare combination of extremely high specific surface area, remarkable thermal/electrical conductivity, an open microstructure, and good thermal stability. The small business, in collaboration with the University of North Carolina, will exploit the newly discovered route to graphene to produce mechanically stable, flexible, mesoporous electrodes for supercapacitors, electrodes that will achieve higher energy storage capacity and enhanced performance. The broader/commercial impact of this project lies in the many applications that can be enabled by supercapacitors. It is expected that the demand for supercapacitors in consumer electronics will increase from $122 million in 2008 to over $550 million in 2014. And, in large storage applications such as wind turbines and hybrid electric vehicles (HEVs), the market value of supercapacitors is expected to expand from $86 million last year, to over $320 million in five years. In the critical technologies of HEVs, supercapacitors will enable improved gas mileage via two primary functions: leveling the dynamic power loads, and recovering available energy from regenerative breaking. The U.S. government has a strong interest in advancing HEVs to lessen dependence on foreign oil and address the global climate challenge. In the private sector, leading automotive companies are developing HEVs as an alternative to internal combustion engine-powered vehicles. Graphene-based supercapacitors offer the potential for attaining the requisite high energy/power density for high pulse power in HEV application.