Graphene Nanoribbons @ Vanadium Oxide Nanostrips for Supercapacitive Energy Storage

•∼15 wt% GNR in VOS@GNRnanocompositeplaysacrucialroleinminimizationtheiR-drop. (*).•VOS@GNR shows high capacitance 335.8 F g−1 at 1 A g−1.•High cycling stability with ∼98.5% capacitance retention & high workable current density.•V2O5 over GNR, improved conductivity and ionic accessibility leading to low iR-drop.

Nanocomposite GNR@VOS composed of V2O5 nanostrips (VOS) embedded over graphene nanoribbons (GNR) is synthesized by facile hydrothermal route and examined as supercapacitor electrode. GNR as support in mere ∼15 wt% plays an important role in patterning the nanocomposite growth as a template. Selective formation of VOS leads to ordered growth and at the same time channelizes the microstructural (shape/size, porosity) as well electrochemical characteristics of the nanocomposite. GNR@VOS so formed is highly accessible electrode matrix in which the underlying GNR acts as conducting support to efficiently minimize the internal resistance (iR-drop) of the electrode. The study suggests that the conductive properties of VOS can be enhanced by integration with GNR displaying increased solid-state conductivity by two orders (bare VOS: 4.2 × 10−4 S m−1 and GNR@VOS: 1.4 × 10−2 S m−1). These attributes result in high energy density for GNR@VOS as 42.09 Wh kg−1 at power density 475 W kg−1. The enhanced performance of GNR@VOS supercapacitor cell from low (1 A g−1) to high current density (20 A g−1) is attributed to the balanced ionic and electronic conduction.

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