Chemical versus Electrochemical Synthesis of Carbon Nano‐onion/Polypyrrole Composites for Supercapacitor Electrodes

Abstract

The development of high-surface-area carbon electrodes with a defined pore size distribution and the incorporation of pseudo-active materials to optimize the overall capacitance and conductivity without destroying the stability are at present important research areas. Composite electrodes of carbon nano-onions (CNOs) and polypyrrole (Ppy) were fabricated to improve the specific capacitance of a supercapacitor. The carbon nanostructures were uniformly coated with Ppy by chemical polymerization or by electrochemical potentiostatic deposition to form homogenous composites or bilayers. The materials were characterized by transmission- and scanning electron microscopy, differential thermogravimetric analyses, FTIR spectroscopy, piezoelectric microgravimetry, and cyclic voltammetry. The composites show higher mechanical and electrochemical stabilities, with high specific capacitances of up to about 800 F g(-1) for the CNOs/SDS/Ppy composites (chemical synthesis) and about 1300 F g(-1) for the CNOs/Ppy bilayer (electrochemical deposition).

Highly Flexible and Planar Supercapacitors Using Graphite Flakes/Polypyrrole in Polymer Lapping Film

“…Among these polymers, polypyrrole is a potential material exhibits high conductivity, good stability in water and air, easy to process and relatively low cost. Polypyrrole/Carbon composite materials such as carbon black/polypyrrole, 24 carbon nanotubes/PPy, 25 carbon onion/PPy, 22 graphene/PPy 26 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 Finally the space between the electrodes were filled with PVA/H 3 PO 4 electrolyte and dried over night in a vacuum oven at 60 °C. The bare GF planar SC was fabricated as same procedure without deposition of polypyrrole film.…”

Recent progress in carbon-based nanoarchitectures for advanced supercapacitors

“…Up to now, several methods have been used for OLC synthesis, and the thermal annealing toward nanodiamond powders has become the most practical strategy [69]. Different synthetic approaches that used various precursors mainly led to the difference in the number of layers and the core character [71]. Recent studies of OLC nanostructures show very interesting physicochemical properties that are attractive for SCs.…”

“…To overcome this drawback, the decoration of OLC outer surface with redox-active, pseudocapacitive materials has been widely explored and verified as an effective approach. PlonskaBrzezinska et al [71] synthesized the CNO/polypyrrole (Ppy) and CNO/SDS/Ppy composites via the pyrrole polymerization on the CNO surface via chemical or electrochemical methods. The synthetic procedures resulted in the difference of their microstructure and electrochemical performances.…”

Carbon Nano‐Onion and Zinc Oxide Composites as an Electron Transport Layer in Inverted Organic Solar Cells

“…Composite materials based on the integration of CNs with other substances can lead to substances possessing the properties of the individual components. The preparation of composites containing CNOs and organic or inorganic components has been reported . In this work, we prepared hybrid nanocomposites containing CNOs and inorganic materials, namely zinc oxide or hydroxide.…”