Preparation of Foam-like Network Structure of Polypyrrole/Graphene Composite Particles Based on Cellulose Nanofibrils as Electrode Material

Abstract

Unusual polypyrrole/graphene/cellulose nanofibril (PPy/GR/CNF) composite particles were fabricated by introducing an in situ oxidative polymerization approach. Structural characterization of the composite particles showed foam-like network morphology with a large surface area of 621 m2/g. The PPy/GR/CNF sample exhibited remarkable capacitance behavior in 1 M Na2SO4. It showed a high specific capacitance of 264.3 F/g at 0.25 A/g, which represents a 51.7% increase compared to that of PPy/GR and a high capacitance of 155.5 F/g even at a high current density of 5 A/g. Meanwhile, it possessed high rate capability and good cycling performance (85.7% capacitance retention even after 1000 cycles). These excellent electrochemical performances were attributed to the structure of PPy/GR/CNF that can provide large surface areas and shorten electron diffusion pathways. More importantly, the CNF stabilized the structure of PPy and prevented chain breakdown during the charge/discharge process, which improved the cycling performance. Hence, this PPy/GR/CNF composite shows great potential for the fabrication of high-capacitance and low-cost supercapacitor electrode materials with good cycling performance.