Paper EH-WeP19
Flexible and Stackable All-solid-state PPy/CNT-web Paper Supercapacitors

Wednesday, December 14, 2016, 4:00 pm, Room Mauka

Increasing demand for wearable and portable electronic devices facilitates development of flexible energy storage systems such as Li-ion batteries and supercapacitors. Carbon nanotubes (CNTs) have a great potential for supercapacitors due to their great electrical properties and excellent flexibility, making them appropriate materials to be used in the backbone of flexible devices. However, low specific capacitance of CNTs limits their practical application in supercapacitors. Combination of CNT and conductive polymer is an effective way to improve the performance of supercapacitors. Among conductive polymers, polypyrrole (PPy) is a promising material for supercapacitor electrodes because of its high capacitance, facile synthesis, and low cost. However, there are several demerits such as poor rate capability and cycling stability of PPy. To overcome these drawbacks, in this study, PPy is deposited onto an ultra-thin CNT paper. Ultra-thin CNT-web paper is prepared by using chemical vapor deposition and direct spinning method, and PPy is electrochemically deposited on the CNT-web paper. Electrochemical characterization of the PPy/CNT-web paper electrodes has been carried out by means of cyclic voltammetry and galvanostatic charge/discharge. They exhibit high specific capacitance of 396 Fg^-1 at a scan rate of 2 mVs^-1 and retain the specific capacitance of 208 Fg^-1 at a scan rate of 500 mVs^-1, which indicates the high rate capability of the electrodes. All-solid-state flexible symmetric supercapacitor is assembled with two PPy/CNT-web paper electrodes, and the symmetric supercapacitor devices can be stacked to form high-density energy devices. Electrochemical performance of the single and stacked PPy/CNT-web paper supercapacitors will be discussed in the presentation.