Fabrication of 2D-Borophene nanosheets anchored S, N-mesoporous carbon nanocomposite (SNC-Bp//SNC-Bp) symmetric device for high-performance supercapacitor application

Innovative advancements in the field of electrochemical energy storage devices have been achieved through the utilization of two-dimensional (2D) materials. These materials possess the remarkable ability to modify the bandgap between layers, exhibit distinctive quantum chemical properties, and feature active functional groups. However, the application of 2D materials such as borophene (Bp) is hindered by issues such as pi-pi restacking and poor ambident stability. In view of this, our research team has successfully synthesized a symmetric supercapacitor device by generating a nanocomposite composed of S, N doped mesoporous carbon (SNC) and 2D-Borophene (SNC-Bp//SNC-Bp). The Bp-nanosheets were effectively synthesized using a liquid phase exfoliation technique and composited with SNC through a solvent-mediated ultrasonication method. Moreover, the synthesized SNC-Bp NCs were comprehensively examined using a range of advanced analytical methodologies to ascertain their elemental composition, morphological attributes, and structural characteristics. Additionally, the cyclic voltammetry and galvanostatic charge-discharge analysis reveal an impressive specific capacitance of 805.3 F/g (Cs1) and 607 F/g (Cs2) at 10 mV/s scan rate and 1 A/g current density, underscoring the remarkable electrochemical performance of the SNC-Bp NCs. Trasatti and Dunn's analysis reveals that the charge storage process is predominantly governed by the capacitive contribution (qi∗)of 95.2 %, with diffusive contributions (qo∗)constituting a minor portion of 4.8 %. Remarkably, the SNC-Bp//SNC-Bp symmetric supercapacitor device (SSD) exhibited outstanding energy and power density values of 29.2 Wh/kg and 3500 W/kg respectively, while maintaining an original capacitance of 90.67 % and a coulombic efficiency of 91.27 %. [Display omitted] •2D-Borophene sheets were composited with S, N-carbon via a facile ultrasonication process.•L-cysteine amino acid functioned as S, N-source which was doped on the porous carbon derived from biowaste.•SNC-Bp NCs showcased 805 F/g at 10 mV/s scan rate in a three-electrode set-up (3 M KOH).•Fabricated SNC-BP//SNC-Bp SSD delivered 230 F/g at 1 A/g within 0–1.4 V operating voltage.•Superior energy and power density of 29.2 Wh/kg and 3500 W/kg were obtained from the SNC-BP//SNC-Bp SSD.