An electrochemically reduced ultra-high mass loading three-dimensional carbon nanofiber network: a high energy density symmetric supercapacitor with a reproducible and stable cell voltage of 2.0 V. Issue 46 (22nd November 2021)

• Record Type: Journal Article
• Authors: Ojha, Gunendra Prasad; Pant, Bishweshwar; Acharya, Jiwan; Park, Mira
• Is Part Of: Nanoscale. Volume 13:Issue 46(2021)
• Page Start: 19537
• Page End: 19548
• Publication Date: 2021-11-22
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/d1nr05943b
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : Thickness and mass-dependent free-standing, highly conductive Na + -LBL 3D-CNF electrodes were fabricated via multi-step fabrication techniques for high-performance symmetric supercapacitors. Abstract : Commercial supercapacitors need a high mass loading of more than 10 mg cm −2 and a high working potential window to resolve the low energy density concern. Herein, we have demonstrated a thick, ultrahigh mass loading (35 mg cm −2 ) and wide cell voltage electrochemically reduced layer-by-layer three-dimensional carbon nanofiber network (LBL 3D-CNF) electrode via electrospinning, sodium borohydride treatment, carbonization, and electro-reduction techniques. During the electro-reduction technique, Na + is adsorbed onto the various defect sites of LBL 3D-CNFs, which properly inhibits the formation of the intermediate HER (hydrogen evolution reaction) product, leading to a wide cell voltage, whereas the LBL 3D-CNF network evokes an opportunity for storing a greater number of charges, resulting in excellent electrochemical performances. A symmetric supercapacitor with a reproducible and stable cell voltage of 2.0 V is constructed and demonstrated. The as-constructed device can deliver an areal energy output of 1922 μW h cm −2 at a power density of 3979 W kg −1 equal to a gravimetric energy density of 27 W h kg −1, and an outstanding cyclic durability of 97.4% after 20 000 GCD cycles. These record-breaking performances would make our device one of the most promising candidates from an industrial point of view.