Rational nanoarchitectonics of polypyrrole/graphene/polyimide composite fibrous membranes with enhanced electrochemical performance as self-supporting flexible electrodes for supercapacitors

Abstract

Constructing self-supporting electrodes with the combination of excellent flexibility and superior electrochemical properties is essential to the development of high-performance supercapacitors for flexible electronics and wearable devices. Herein, a highly flexible polypyrrole/reduced graphene oxide/modified-polyimide composite fibrous membranes (PPy/RGO/M-PI CFMs) are prepared via electrostatic self-assembly of reduced graphene oxide (RGO) and in-situ deposition of polypyrrole onto SnCl2-modified polyimide electrospun fibrous membranes (M-PI FMs). M-PI FMs ensure rich pore structure and remarkable flexible properties, the electronic conductivity of the sample is greatly promoted by RGO, and polypyrrole (PPy) provide the capability of high redox pseudo capacitive charge storage for the electrode. Benefiting from the compact assembly of RGO and the uniform deposition of polypyrrole on the fiber surface of the M-PI FMs, the synthesized PPy/RGO/M-PI CFMs have a remarkable area capacitance of 1437.1 mF cm−2, a long cycle life of 84.9 % retention over 5000 cycles, and outstanding mechanical stability. And the assembled symmetric supercapacitor with PPy/RGO/M-PI CFMs deliver an exceptional area capacitance of 363.1 mF cm−2, superior energy density of 32.3 μWh cm−2 and 77.6 % capacitance retention after 5000 cycles. Therefore, this flexible and free-standing PPy/RGO/M-PI CFMs can be regarded as a promising candidate for flexible supercapacitor electrodes.