Synthesis of partially graphitic nanoflake-like carbon/Fe₃O₄magnetic composites from chitosan as high-performance electrode materials in supercapacitors

Abstract

Flake-like carbon-based iron oxide composites were prepared via a hydrothermal reaction, followed by a carbonization processes, and they exhibit excellent recycling durability.

A reduced graphene oxide modified metallic cobalt composite with superior electrochemical performance for supercapacitors

“…Characterization of electrode materials 25 The XRD patterns of GO, reduce graphene oxide (rGO) and rGO/Co composite are presented in Fig. 1.…”

“…In the Raman spectrum of rGO/Co, the bands observed at 1349 and 1589 cm -1 were attributed to the D and G band of rGO component, respectively. 4b, bare GO is featured with a layer-by-layer structure with 25 dense stacking of GO sheets. 27 For comparison 5 purpose, we also tested the Raman spectrum of GO, in which the D and G band were positioned at 1352 and 1594 cm -1 , respectively.…”

“…Supercapacitors, as one of the important electrochemical energy storage devices, have received intensive attentions due to their outstanding characteristics including high power density, fast 25 charge/discharge process, environmentally benignity and long lifespan which have been widely used in portable electronics, power gids, electrical vehicles and aerospace applications. [1][2][3][4][5][6] However, the relatively lower energy density compared with rechargeable batteries and fuel cells highly restrict its practical 30 applications.…”

“…As a result, rGO/Co displayed good electrochemical 15 performances, especially in an asymmetric supercapacitor test system, which achieved a maximum energy density of 40.7 Wh·kg -1 at a power density of 1585.0 W·kg -1 . The suspension was continuously 25 stirred for 30 min and then at 35 °C for 2 h. After the suspension cooled down to room temperature, it was placed into 400 mL of ice solution under stirring. Graphite oxide (GO) was synthesized by an improved Hummers' method.…”

“…[23][24][25][26] Nevertheless, on the one hand, the previous reported research of such kind of 70 composites were in generl in a symmetric capacitor system resulted in a limited improvement in energy density; on the other The prepared rGO/Co//AC asymmetric supercapacitor displayed good electrochemical performances, which achieved a maximum energy density of 40.7 Wh·kg -1 at a power density of 1585.0 W·kg -1 . Such a composite exhibited an impressive performance when used in (asymmetric) supercapacitors.…”