Hydrothermal synthesis of nanostructured graphene/polyaniline composites as high-capacitance electrode materials for supercapacitors

Abstract

As known to all, hydrothermal synthesis is a powerful technique for preparing inorganic and organic materials or composites with different architectures. In this reports, by controlling hydrothermal conditions, nanostructured polyaniline (PANi) in different morphologies were composited with graphene sheets (GNS) and used as electrode materials of supercapacitors. Specifically, ultrathin PANi layers with total thickness of 10–20 nm are uniformly composited with GNS by a two-step hydrothermal-assistant chemical oxidation polymerization process; while PANi nanofibers with diameter of 50~100 nm are obtained by a one-step direct hydrothermal process. Benefitting from the ultrathin layer and porous structure, the sheet-like GNS/PANi composites can deliver specific capacitances of 532.3 to 304.9 F/g at scan rates of 2 to 50 mV/s. And also, this active material showed very good stability with capacitance retention as high as ~99.6% at scan rate of 50 mV/s, indicating a great potential for using in supercapacitors. Furthermore, the effects of hydrothermal temperatures on the electrochemical performances were systematically studied and discussed.

Flexible and Mechanically Durable Asymmetric Supercapacitor Based on NiCo‐Layered Double Hydroxide and Nitrogen‐Doped Graphene Using a Simple Fabrication Method

“…This is significantly higher than previously reported for NG materials (Table S4, Supporting Information). Furthermore, the C s value of NG obtained by the present method was even comparable to those of metal oxide, metal oxide/graphene, and polymer/graphene materials . It is important to note that C s of NG was still as high as 200 F g −1 even at a high current density of 50 A g −1 (Figure c).…”

Graphene-Based Heterogeneous Electrodes for Energy Storage

“…Hydrothermal method is an efficient and cost-effective approach for the assembly of metastable crystalline structures [53][54][55][56][57], especially for the heterogeneous structure with solid interface contact [58][59][60][61]. As for the graphene based heterogeneous electrode materials, the use of hydrothermal assembly could effectively reduce the cost, improve the crystallinity, and consolidate the interface contact, and therefore improve the energy storage performance.…”

“…In other cases, hydrothermal assembly could also be used to fabricate the polyaniline (PANI)/graphene [58,63], TiO 2 /graphene [64], Mn 3 O 4 /CeO 2 /graphene [65], α-Fe 2 O 3 /graphene [59], and Mn 3 O 4 /graphene electrode materials [66]. As illustrated in the literatures, the hydrothermal assembly of graphene based heterogeneous electrode materials is usually starting with the graphite oxide (GO), the active electrode materials and/or surfactants, which should be Schematic illustration for ball milling synthesis of Si@SiO x /grapheme anode material [47].…”

Synthesis, characterization and Hall-effect studies of highly conductive polyaniline/graphene nanocomposites

“…The important properties being having thermal conductivity of ~ 5 × 10 3 W m −1 K −1 , the higher electron mobility about 200,000 cm 2 V −1 s −1 with electron densities in the order of ~ 2 × 10 11 cm −2 . The fact that all of these exceptional properties being originated from a single material has stimulated greater interest in Gr and has attracted researchers to use it in numerous scientific and technological applications such as field effect transistors, field emission devices, solar cells, actuators, batteries and in super capacitors [2][3][4][5][6][7][8]. The combination of PANI with Gr is intentive not only to fortify conducting polymers but also to produce interesting electronic properties on the basis of morphological modification or electronic interaction between the two materials.…”