Polymer-based flexible electrodes for supercapacitor applications

In recent years, with the rapid proliferation of portable and wearable electronics, the fabrication of flexible energy storage devices (FESDs) has become one of the prime interests of current research. Among the flexible energy storage electrode materials, conducting polymers (CPs) are more significant materials, because of their unique advantages, which include ease of synthesis, economy, good conductivity, and flexibility. Combination of the CPs with either carbon-based materials or metal oxide and metal sulfide materials can greatly enhance their physicochemical properties, as well as their electrochemical properties. The current chapter summarizes current research based on innovative configurations of flexible supercapacitors (FSCs) for energy storage applications, including freestanding, interdigitated, asymmetric, and fiber-based SCs. We also demonstrate the synthesis and electrochemical applications of individual CPs-in particular, polyaniline (PANI), polypyrrole (PPy), and poly(3,4-ethylenedioxythiophene) (PEDOT), as well as their binary and ternary composites. The effects of one-dimensional materials, as well as redox electrolytes, on electrochemical properties are discussed. The realtime practical applications of these composite materials are also demonstrated. In addition, a summary of various recent flexible electrodes is also presented.