Highly Stable Supercapacitor Devices Based on Three-Dimensional Bioderived Carbon Encapsulated g-C₃N₄ Nanosheets

Abstract

Owing to the increasing demand for sustainable and ecofriendly energy storage devices such as supercapacitors, it is vital to continuously search for highly stable and cost-effective electrode materials with high energy and power densities. Herein, a 3D/2D metal-free mesoporous composite of graphitic carbon nitride (GCN) and bioderived carbon (Bio-C x ) is investigated as an energy storage electrode material. This composite overcomes the low conductivity and low capacitance limitations of GCN while enjoying its high corrosion resistance, high nitrogen content, and unique 2D structure. The GCN/Bio-C x composite exhibits a fairly wide operating potential window of 1.2 V in 0.5 M H 2 SO 4 aqueous electrolyte with a high capacitance of 300 F/g at 1 A/g. This high performance was ascribed to the huge number of available active sites, large surface area, and the unique 3D/2D structure. The assembled device employing the GCN/ Bio-C x composite as the positive electrode and mesoporous nitrogen-doped carbon (MPNDC) as the negative electrode showed an ultrahigh-energy density of 53.72 Wh/kg and a power density of 900 W/kg. The GCN/Bio-C x //MPNDC device retains ∼100% of its initial capacitance after 13 000 charge/discharge cycles with 100% Columbic efficiency.

Binder-free Mn–V–Sn oxyhydroxide decorated with metallic Sn as an earth-abundant supercapattery electrode for intensified energy storage

“…The results reveal an enhancement in the performance upon activation, which may be ascribed to the better accessibility of ions, high electronic diffusion rate, enhanced mass transportation, and electronic conduction at the electrode/electrolyte interface. 41 To confirm these assumptions, the potentiostatic electrochemical impedance spectroscopy (PEIS) measurements were recorded. The Nyquist plot shown in Fig.…”

“…Note that the + and − signs refer to polarization charge. The specific capacitances for the three- and two-electrode systems in F g −1 were calculated from (CV) using eqn (2): 40,41 where C CV is the calculated specific capacitance (F g −1 ), Δ V is the potential window ( V ), ν is the potential scan rate (mV s −1 ), m is the active mass of the electrode material ( g ), and I is the capacitive current ( A ). Due to the non-linear discharge profiles of the as-fabricated composite and the device, the specific capacitances can be obtained using the CED curves by using the integral form of C CED = i × d t /Δ V as depicted by eqn (3): 42,43 where I is the applied current ( A ), is the area under the discharge curve, m is the mass of the active material, and Δ V is the potential window ( V ).…”

“…Asymmetric supercapacitors are extremely promising in realworld applications owing to their wide operating voltage window upon the proper combination of negative and positive electrodes. 7,41,46,95 Therefore, a sandwich-like supercapacitor cell was assembled using the SMVS ternary metal oxyhydroxide composite and hierarchical nitrogen-doped carbon (HDC) as the anode and cathode, respectively, separated by a cellulose lter paper. It is worth mentioning that HDC is a good cathode material, producing high capacitance with a wide operating window of 1.2 V; see the ESI † for more details.…”

A Comprehensive Review of Graphitic Carbon Nitride (g-C3N4)–Metal Oxide-Based Nanocomposites: Potential for Photocatalysis and Sensing

“…g-C 3 N 4 has become an important material in chemistry, physics and engineering because of its facile, low-cost, environmentally-friendly preparation methods with promising stability and good physicochemical properties for use in a wide range of applications [2]. Compared with other semiconductors, g-C 3 N 4 can be easily synthesized by various methods with desirable electrical structures as well as morphologies, and high thermal stability up to 600 • C in the air [3,4].…”

Unleashing the Full Potential of Electrochromic Heterostructured Nickel–Cobalt Phosphate for Optically Active High-Performance Asymmetric Quasi-Solid-State Supercapacitor Devices

“…8 Therefore, expanding the operating window would efficiently enhance the energy density of ultracapacitors. 9 Consequently, fabricating asymmetric supercapacitor devices has become a modern approach to achieving a high working range and specific capacity without sacrificing the power density. 10 The asymmetric supercapacitor devices, especially the hybrid type, aim to combine several merits by connecting the redox active electrodes (faradaic), which are usually applied as positive electrodes due to their high conspicuous capacity, and carbonbased electrodes (nonfaradaic electric double layer; EDL), which are considered potential negative electrodes as they are characterized with a high operating window and fair specific capacitance.…”