The enhanced capacitance performance of the modified polypyrrole with the mixture of carbon nanomaterials

Abstract

In this work, the polypyrrole modified with copper phthalocyanine‑3,4′,4″,4‴‑tetrasulfonic acid tetrasodium salt (CuPcTs), named as c-PPy, was mixed with different carbon nanomaterials (single-walled carbon nanotubes (SWCNTs), multi-walled carbon nanotubes (MWCNTs), graphene (G), graphene oxide (GO), signal-walled carbon nanohorns (CNH)) to investigate the influence on the capacitance performance. Herein, compared with the specific capacitance of c-PPy, the c-PPy/SWCNTs exhibited the maximum specific capacitance according to cyclic voltammetry (CV) curves at the scan rate of 1 to 100mVs−1 and the maximum specific capacitance was 238Fg−1 @ 1mVs−1. The c-PPy/MWCNTs exhibited the highest specific capacitance according to galvanostatic charge/discharge (GCD) characteristics at the current density of 0.1 to 1Ag−1, while the c-PPy/SWCNTs exhibited the highest specific capacitance at the current density of 1 to 10Ag−1. The capacitance performance of c-PPy/G hybrid electrodes was larger than that of c-PPy electrode, while that of c-PPy/GO and c-PPy/CNH hybrid electrodes was smaller. And the specific capacitance of c-PPy/SWCNTs hybrid electrodes was slightly decreased at high current densities and scan rates. The capacitance retention of c-PPy/MWCNTs and c-PPy/SWCMTs hybrid electrodes was approximately 80% and 75% (after 6000cycles). It was assumed that the crosslink of CNTs was overlapped with c-PPy in c-PPy/CNTs hybrid electrodes to construct a three dimension (3D) porous conductive network to provide ion diffusion channels, electron transport pathways, high specific surface area and active sites. The cowered G played a slightly positive influence on the construction of continuous conductive c-PPy network, while the relative flat GO had a very negative impact. The particle-like CNH was not tightly adhered to the fiber-like c-PPy, which made the fluffy hybrid nanostructure. Therefore, the c-PPy/SWCNTs can be used as the active electrode of high-capacity energy storage devices.