supercapacitors can store several times more charge in a given volume or mass than traditional capacitors, have faster charge and discharge rates, and are very stable. Over the past few years, researchers have begun working on making supercapacitors that are transparent and flexible due to their potential use in a wide variety of applications.
“Potential applications can be roughly divided into two categories: high-aesthetic-value products, such as activity bands and smart clothes, and inherently transparent end-uses, such as displays and windows,” coauthor Tanja Kallio, an associate professor at Aalto University who is currently a visiting professor at the Skolkovo Institute of Science and Technology. “The latter include, for example, such future applications as smart windows for automobiles and aerospace vehicles, self-powered rolled-up displays, self-powered wearable optoelectronics, and electronic skin.
The type of supercapacitor developed here, called an electrochemical double-layer capacitor, is based on high-surface-area carbon. One prime candidate for this material is single-walled carbon nanotubes due to their combination of many appealing properties, including a large surface area, high strength, high elasticity, and the ability to withstand extremely high currents, which is essential for fast charging and discharging.
Transparent and flexible energy storage devices have garnered great interest due to their suitability for display, sensor and photovoltaic applications. In this paper, researchers report the application of aerosol synthesized and dry deposited single-walled carbon nanotube (SWCNT) thin films as electrodes for an electrochemical double-layer capacitor (EDLC). SWCNT films exhibit extremely large specific capacitance (178 F g−1 or 552 μF cm−2), high optical transparency (92%) and stability for 10 000 charge/discharge cycles. A transparent and flexible EDLC prototype is constructed with a polyethylene casing and a gel electrolyte.
The researchers are currently working on a new type of stretchable and transparent single-walled carbon nanotube supercapacitor. They are confident that one can create prototypes based on carbon nanotubes that might withstand 100% elongation with no performance degradation
SOURCE – journal Nanotechnology, Physorg, Aalto University