Two different lines of research in Korea and Australia seem to be heading toward practical supercapacitors with energy densities approaching the lower end of battery technology while offering better charging efficiency and extended lifetimes. Santhakumar Kannappan, a researcher at the Gwangju Institute of Science and Technology in Korea has led a team who reduced graphene oxide particles with hydrazine in water, then agitated the slurry with ultrasound. This produces a “highly porous form of graphene that has a huge internal surface area,” equivalent to a basketball court for every gram. They pack the resulting powder into a coin-shaped cell, dry it at 140° C and a pressure of 300 kilograms per centimeter (4,267 pounds per square inch) for five hours. Electrodes made this way and saturated in EBIMF 1 M electrolyte have a specific capacitance of 150 Farads per gram, an energy density of 64 Watt-hours per kilogram and a current density of 5 Amps per gram. MIT’s Technology Review …
The Layered Look in Batteries
Gurpreet Singh, assistant professor of mechanical and nuclear engineering, and his research team at Kansas State University in Manhattan, Kansas, are working out less expensive, more efficient ways to create nanomaterials and lithium-ion batteries. “We are exploring new methods for quick and cost-effective synthesis of two-dimensional materials for rechargeable battery applications,” Singh said. “We are interested in this research because understanding lithium interaction with single-, double- and multiple-layer-thick materials will eventually allow us to design battery electrodes for practical applications. This includes batteries that show improved capacity, efficiency and longer life.” Researchers grew graphene films on copper and nickel foils in less than 30 minutes by quickly heating them in a furnace in the presence of argon, hydrogen and methane gases – significantly at atmospheric pressure. Not needing to use a vacuum to create these films saves energy, time and cost, according to Singh. Researchers used the films to create the negative electrode of a lithium-ion cell and test the …