Two‐Dimensional Layered Metallic VSe₂/SWCNTs/rGO Based Ternary Hybrid Materials for High Performance Energy Storage Applications

Abstract

In this work, the ternary hybrid structure VSe 2 / SWCNTs/rGO is reported for supercapacitor applications. The ternary composite exhibits ah igh specific capacitance of 450 Fg À1 in as ymmetric cell configuration, with maximum energy density of 131.4 Wh kg À1 and power density of 27.49 kW kg À1 .The ternary hybrid also shows acyclic stability of 91 %a fter 5000 cycles. Extensive density functional theory (DFT) simulations on the structure as well as on the electronic properties of the binary hybrid structure VSe 2 /SWCNTsa nd the ternary hybrid structure VSe 2 /SWCNTs/rGO have been carriedo ut. Due to as ynergic effect, there are enhanced density of states near the Fermi level and higher quantum capacitance for the hybrid ternary structure compared to VSe 2 /SWCNTs, leading to higher energy and powerd ensity for VSe 2 /SWCNTs/rGO, supporting our experimental observation. Computed diffusione nergyb arriero fe lectrolyte ions (K + )p redicts that ions move faster in the ternary structure, providing higherchargestorage performance.[a] K. A. Sree Raj Centre for Nanoa nd MaterialS cience, Jain University Jain global campus,J akkasandra, Ramanagaram, Banglore562112 (India)

1T-VS2/MXene Hybrid as a Superior Electrode Material for Asymmetric Supercapacitors: Experimental and Theoretical Investigations

“…Typically, if b = 1, then the process is dominated by surface dominant non-faradaic reactions. If b = 0.5, then the process is dominated by faradaic or slow-diffusion reactions, which obeys Cortell’s equations i = a υ b …”

“…Generally, supercapacitors have three parts of charge storage kinetics: first, the formation of the EDL, second, the rapid redox interaction at the interface of the electrode and electrolyte, both parts contributing to the solid-state diffusion of ions into the electrode material . The total charge storage contribution can be defined as below in eq . where K 1 (υ) and K 2 (υ) 0.5 attribute to the total current contribution of both capacitive and diffusion-controlled regions.…”

“…The K 1 and K 2 are calculated from the slope and intercept of i ( V )/ v 0.5 versus (υ) 0.5 the plot, respectively …”

“…The slurry of active material was prepared by dispersing the sample in isopropyl alcohol and Nafion resin in a ratio of 1:19 . After ultrasonication for 15 min, the slurry was drop cast on nickel foam substrates followed by drying in a vacuum oven for 2 h at 60 °C.…”

“…The slurry of active material was prepared by dispersing the sample in isopropyl alcohol and Nafion resin in a ratio of 1:19. 25 After ultrasonication for 15 min, the slurry was drop cast on nickel foam substrates followed by drying in a vacuum oven for 2 h at 60 °C. Finally, the nickel foam electrodes were compressed by applying hydraulic pressure of 5 Ton before doing the electrochemical measurements.…”