High-performance symmetric supercapacitors based on carbon nanotube/graphite nanofiber nanocomposites

Abstract

This work reports the nanocomposites of graphitic nanofibers (GNFs) and carbon nanotubes (CNTs) as the electrode material for supercapacitors. The hybrid CNTs/GNFs was prepared via a synthesis route that involved catalytic chemical vapor deposition (CVD) method. The structure and morphology of CNTs/GNFs can be precisely controlled by adjusting the flow rates of reactant gases. The nest shape entanglement of CNTs and GNFs which could not only have high conductivity to facilitate ion transmission, but could also increase surface area for more electrolyte ions access. When assembled in a symmetric two-electrode system, the CNTs/GNFs-based supercapacitor showed a very good cycling stability of 96% after 10 000 charge/discharge cycles. Moreover, CNTs/GNFs-based symmetric device can deliver a maximum specific energy of 72.2 Wh kg−1 at a power density of 686.0 W kg−1. The high performance of the hybrid performance can be attributed to the wheat like GNFs which provide sufficient accessible sites for charge storage, and the CNTs skeleton which provide channels for charge transport.

Fabrication of 9.6 V High-performance Asymmetric Supercapacitors Stack Based on Nickel Hexacyanoferrate-derived Ni(OH)2 Nanosheets and Bio-derived Activated Carbon

“…EDLC typically involves using high surface area carbon based materials like activated carbon, carbon nanotube and graphene as electrode materials 13,14 . Since EDLC does not involve charge transfer at electrode/electrolyte interface, the chance of chemical or composition changes associated with the non-faradaic process is none 15,16 . For this reason, charge storage in EDLC is highly reversible, which makes them worthy candidate for achieving very high cycling stabilities and they generally operate with stable performance characteristics for a great many charge-discharge cycles 17–19 .…”

“…However, because of its high cost and toxicity, RuO 2 as an electrode material for supercapacitors in a commercial level is being lot more cogitated. Hence, transition metal (such as Fe, Co, Cu, Ni and Mn) oxides/hydroxides are under extensive investigation as alternate electrode materials for supercapacitors 15,28,29 . Among these metal oxides/hydroxide, Ni(OH) 2 is a potential candidate due to its elemental abundance (second most abundant element in the earth’s core), non-toxicity, easy preparation in various shapes at the nanoscale with excellent electrochemical performance like high theoretical specific capacity of 1041 C/g 25 .…”

Molybdenum Disulphide Heterointerfaces as Potential Materials for Solar Cells, Energy Storage, and Hydrogen Evolution

“…Broadly these can be classified into two main categories. One is an electrochemical double‐layer capacitor (EDLC), wherein the charge is stored by forming an electrical double layer, also known as a Helmholtz layer, in close vicinity with the electrode surface and electrolyte, typically with just a monolayer separation . Second is a pseudo (Faradic)‐capacitor, wherein energy is stored by a fast reversible surface reduction/oxidation process in addition to the presence of EDLC.…”

Novel mesoporous electrode materials for symmetric, asymmetric and hybrid supercapacitors

“…Their entanglement in the nanocomposites helps in enhancing the supercapacitor performance as the charge transfer between the filler components will be easy and the transport of electrons through the 1D CNTs are very fast. Zhou et al have synthesized a novel CNT/graphite nanofiber nanocomposite by CVD method [99]. The schematic of CNTs/graphite nanofibers architecture is depicted in figure 5(a) and a symmetric supercapacitor was fabricated using CNTs/graphite nanofibers electrodes (figure 5(b)).…”