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The thriving energy demand of the gradually increasing population and modernised life style requires development in energy storage devices for usage in commercial electronic devices. In this particular work, we have explored electrochemical performances of bimetallic oxide Ag 2 WO 4 nanorods and tuned its performance by decorating it on the nitrogen doped carbon nanofiber (N-CNF). The Ag 2 WO 4 nanorods are synthesised by a facile route of co-precipitation method followed by ultrasonication with N-CNF. The synthesised Ag 2 WO 4 nanorods was found electrochemically active and the incorporation of N-CNF end up boosting its electrochemical performances. The obtained nanocomposites were characterised by various advanced techniques. The amount of N-CNF was determined by characterisation via the potentiostatic and galvanostatic cycle measurements and electrochemical impedance spectroscopy (EIS). The electrochemically active Ag 2 WO 4 with 20 wt% of N-CNF (Ag 2 WO 4 /N-CNF b) exhibited 2.2-fold higher charge storage capacity than pristine Ag 2 WO 4. The Ag 2 WO 4 /N-CNF b exhibited specific capacitance as high as 330 F g−1 at a constant applied current density of 1 A g−1 in 1 M KOH. The improved capacity may be due to conductive pathways provided by N-CNF. The Ag 2 WO 4 got well decorated over the N-CNF facilitating the active sites interaction with electrolyte. The symmetric device fabricated with Ag 2 WO 4 /N-CNF b electrodes exhibited excellent energy density of 10 W h kg−1 at 6000 W kg−1 at 5 A g−1. The Ag 2 WO 4 /N-CNF b electrode long-term stability has been minutely observed; the high Coulombic efficiency of 90% and high rate of capacity retention 98% even after 3000 cycles. Owing to these excellent electrochemical properties, the research work can potentially widen the opportunity to explore other profound bimetallic oxides and its nanocomposites with conductive carbon-based matrix for energy storage applications. [Display omitted] • Ag 2 WO 4 nanorods, easily synthesised by co-precipitation method is found to be electrochemically active in 1 M KOH. • Decorating Ag 2 WO 4 on N-doped CNF boost electrochemical charge storage owing to high active sites and improved conductivity. • The Ag 2 WO 4 @N-CNF nanocomposite electrode has been used further to develop electrochemical symmetric supercapacitors. • Such work open door for exploring other bimetal oxides and carbon composites and synergistic effect for various applications. [ABSTRACT FROM AUTHOR]

A series of highly homogeneous polyaniline@N/P co-doped carbon nanofibers (PANI@NPCNFs) composites have been prepared by in-situ polymerization of aniline on the surface of NPCNFs. Vertically oriented PANI nanothorns are achieved by introducing phosphorus groups on the surface of NPCNFs. The optimized PANI@NPCNFs composite demonstrates outstanding electrochemical performance with high specific capacitance (436 F g −1 at 0.5 A g −1 ), high rate capability (79% capacitance retention at 20 A g −1 relative to that at 0.5 A g −1 ), and good stability (96% capacitance retention after 1000 cycles at 10 A g −1 ). The excellent electrochemical performance can be attributed to the surface phosphorus-oxygen groups which bridge the gaps between PANI and NPCNFs, leading to highly enhanced charge transfer dynamics. [ABSTRACT FROM AUTHOR]

Heteroatom-doped mesoporous carbon nanofibers (HMCNFs) were prepared by direct carbonization of highly cross-linked organic–inorganic hybrid polymeric nanofibers (PNFs) under an inert atmosphere. The HMCNFs were of large Brunauer–Emmett–Teller (BET) surface area, uniform mesopore (with diameter 4 nm), and high content of heteroatoms. Electrodes prepared by using HMCNFs showed a high specific capacitance of 214.9 F/g in 6 M KOH electrolyte, because of the large BET surface area and high content of heteroatoms. This work involved preparation of carbon nanofibers from a novel precursor and used the nanofibers in the fabrication of high-performance supercapacitor electrodes. [ABSTRACT FROM AUTHOR]