All-Organic Electrochromic Supercapacitor Electrodes

The need for determining the instant capacity of an energy storage device has led to the integration of an indicator gauge in batteries. Consumers only have to press the contact points on the battery to activate a thermochromic indicator, which measures the heat resistance of the device. This can be implemented in a supercapacitor through electrochromism, eliminating the necessity to press on the contact points. With this motivation, here we report on the fabrication and characterization of all-organic multichromatic electrodes for supercapacitors. A new conducting polymer (CP) has emerged as a promising active material both for its electrochromic and electrochemical properties combined in a single device, where single walled carbon nanotube (SWNT) thin films are used as the current collectors. CP experiences reversible and rapid multiple color changes with respect to its charged state. The specific capacitance of the SWNT/CP nanocomposite electrodes was found to be 112.4 F/g at a current density of 1 A/g. The power density can reach 16.6 kW/kg and electrodes show good capacity retention (82%) upon cycling for 12500 times. Fabricated all-organic supercapacitor electrodes simply integrate electrochromism and energy storage in one device and this structure holds high potential for the development of smart supercapacitors.