The regions indicated by arrows identify the performances achieved by the UCLA group. Credit: George Gruner
A UCLA team has reported in Nano Letters that it has “printed” a supercapacitor for the first time.
The group, led by George Grüner, accomplished their feat by spraying carbon nanotubes onto paired sheets of film separated by a gel electrolyte. Each sheet acts a charge collector. News about Grüner’s work started appearing in 2007, when he reported using a similar process to make batteries from two layers of film containing carbon nanotubes and a third layer of zinc foil.
A paper on Gruner’s web site says his group uses “a combination of novel, high surface area electro-active andelectrically conducting materials. Novel forms of carbon, called carbon nanotubes and graphene are experimented with together with various polymer, such as polyaniline, fibers and oxide materials such as TiO2 in nanoscale form. Research to date has demonstrated that by a combination of such materials performance figures significantly exceeding that of devices currently available are feasible.
The IEEE’s Spectrum Online reports that the supercapacitor “has a power density of 70 kilowatts per kilogram and an energy density of 9 watt-hours per kilogram, which is comparable to other supercapacitors made using carbon nanotubes.”