Search

Graphical abstract Highlights • p -aminophenyl graphene/polyaniline nanocomposites have a cross-linking structure. • The cross-linking structure improves the electrochemical performance. • The electrode displays a large specific capacitance of 1092.3 F g−1 at 5 mV s−1. Abstract The purpose of this study is to report an effective approach to improve the electrochemical performance of polyaniline electrode by fabricating para-aminophenyl graphene/polyaniline cross-linking nanocomposites (PAG/PANI). The chemical graft between PAG and PANI, and the electrostatic incorporation between PANI inter-chains could provide the stable structural foundation for the improvement of cyclic stability. HCl and 1,5-naphthalene sulfonic acid (NSA) were both used as dopants to guarantee high doping level of PANI. The PAG/PANI electrode had a high specific capacitance of 1092.3 F g−1 at 5 mV s−1, and also showed a high cyclic stability after 3000 cycles. These results indicated that the PAG/PANI electrode would have a broad application prospect in energy storage device. [ABSTRACT FROM AUTHOR]

• A brand-new two-step reaction mechanism of ONA electrode is proposed in AIB. • The π-π stacking structures of π-COCs can contribute capacity directly. • The ONA show the co-existence of high capacity and excellent cycle stability in AIB. Π-conjugated organic compounds (π-COCs), as a potential electrode material, mainly emphasized the effects of functional groups and intramolecular π-conjugated system on charge storage in the past studies. In this work, we discovered a brand-new two step energy storage mechanism for π-COCs using oligomeric naphthalene (ONA) with intermolecular π-π stacking structure as electrode material in Al ion battery system. The electrochemical reaction of ONA is identified as the synergistic work of the chemical-adsorption of AlCl 4 - anions at low potential and the π···[AlCl 4 ]···π interaction at high potential. Based on this, the Al-ONA battery exhibits an excellent electrochemical performance (high specific capacity of 450 mAh/g at 0.1 A/g, long cycle life without attenuation for 4000 cycles at 1 A/g). This discovery of the energy storage mechanism, especially for the π···anion···π interaction, for π-COCs materials opens the door to exploring high performance organic electrode materials in energy storage field. [ABSTRACT FROM AUTHOR]

Polyaniline attracts increasing attention in electrochemical devices, present works focus on improving its specific capacitance and electrochemical stability. In this paper, graphene grafted polyaniline copolymer (G-PC) with conjugated structure was prepared via in-situ chemical oxidation polymerization using p -phenylenediamine (PPDA) and triphenylamine (TPA) as comonomers. The large conjugated system facilitates the charge transfer of the G-PC composites, thereby enhances their electrical conductivity and electrochemical properties. The resultant G-PC electrode demonstrated an enhanced specific capacitance of 1701.1 F/g at a scan rate of 5 mV/s and a high retention after 4000 charge/discharge cycles in a three-electrode system. Finally, the assembled solid-state supercapacitor (SSC) with G-PC electrodes improved energy density up to 15.3 Wh/kg at a power density of 50 W/kg showing a capacitance retention of 94.9% after 5000 electrochemical cycles. Unlabelled Image • Graphene grafted polyaniline copolymers are prepared for supercapacitor. • The electrodes exhibit an enhanced specific capacitance and cyclic stability. • The assembled solid-state supercapacitor is promising in energy storage. [ABSTRACT FROM AUTHOR]