Co electro deposition of the MnO2 PEDOT:PSS nanostructured composite for high areal mass, flexible asymmetric supercapacitor devices
To meet the rapidly growing demand, it is necessary to develop novel flexible energy storage devices with a high energy density in a limited area, a fast charging ability, a low cost for mass production and a miniaturized device size. To address the above issues, here we introduce the co electro deposition strategy, which is able to prepare an electrode material with a high areal capacitance (1670 mF cm 2 at 0.5 mA cm 2) a high areal mass (8.5 mg cm 2) an excellent mechanical robustness, a high through put and great convenience even on a piece of a ubiquitous stainless steel mesh current collector. Based on this advancement, we are able to obtain an ultrathin (less than 200 mm) aqueous asymmetric supercapacitor device with a high energy density (1.8 x 10 3 W h cm 3) a high power density (0.38 W cm 3 at 3.62 x 10 4 W h cm 3) and an excellent rate capability. This energy storage device is integrated into a prototype smart card to drive a light emitting diode (LED) indicator, which is charged for 5 seconds and can light up the indicator for more than 2 hours, demonstrating great promise in miniaturized novel flexible energy storage devices.