Encapsulation of Redox p-Benzoquinone into Microporous Carbon Frameworks by a Diamine Covalent-Grafted Strategy for Aqueous Hybrid Supercapacitors

Abstract

Aqueous hybrid supercapacitors (AHSs) with a wide operating voltage and intrinsic safety are emerging as promising energy storage devices, while their energy densities are still greatly restricted by carbon-based negative electrodes. Developing a high-performance redox system for carbon electrodes is one of the potential strategies to realize the practical utilization of AHSs. Herein, we present a covalent-grafted strategy to encapsulate redox p-benzoquinone (PBQ) into microporous carbon frameworks by using p-phenylenediamine (PPD) as a bridging agent. Both experimental and theoretical analysis reveal that the diamine groups from PPD play a vital role in chemically bonding PBQ with the microporous surfaces of carbon materials, which deliver a great deal of electronic delocalization throughout the redox-active sites and conductive carbon regions. As such, the obtained carbon electrodes grafted by the redox PBQ and PPD species facilitate charge transfer and consequently exhibit excellent charge storage performances. These are highlighted by an extremely high specific capacitance of 377 F g–1 at a current density of 0.5 A g–1 and 276 F g–1 at 100 A g–1 with a superior rate capability of 73%. Impressively, the assembled AHSs based on covalently grafted carbon electrodes (AC-PPD-PBQ) and NiCoAl-layered double hydroxides/carbon nanotubes (NiCoAl-LDH@CNT) demonstrate a maximum energy density of 70.9 W h kg–1 with a wide voltage window of 1.8 V and good cycling stability with 84.4% of initial capacitance after 5000 cycles. This work provides insights into the fabrication of high-performance carbon electrodes by encapsulating redox species into microporous frameworks.

Recent advances in aqueous and non-aqueous alkali metal hybrid ion capacitors

“…Bonding redox-active molecules to specic functional groups on the surface of carbon electrodes is also a direction worth going into, where stronger interfacial interactions between the redox-active molecules and the conductive network also endow the carbon electrodes with fast reaction kinetics and good cycling stability. 510 In addition to enhancing the capacitance of porous carbon itself, researchers have explored ways to boost the energy density of hybrid capacitors by expanding the operating potential range of the activated carbon cathode while meeting high power requirements. AC's high specic surface area and the presence of oxygenated substances on its surface are advantageous properties.…”

“…Bonding redox-active molecules to specific functional groups on the surface of carbon electrodes is also a direction worth going into, where stronger interfacial interactions between the redox-active molecules and the conductive network also endow the carbon electrodes with fast reaction kinetics and good cycling stability. 510…”

From wasted polymers to N/O co-doped partially graphitic carbon with hierarchical porous architecture as a promising cathode for high performance Zn-ion hybrid supercapacitors

“…[1][2][3][4][5][6][7][8] Of these renewable energy storage technologies, the novel aqueous Zn-ion hybrid supercapacitors (ZIHSCs) constructed from a battery-like Zn metal anode via a reversible Zn 2+ deposition/stripping reaction and a capacitor-like carbon-based cathode via a speedy Zn 2+ adsorption/desorption with Zn-ion electrolyte integrate the high power output of supercapacitors and high energy output of batteries, which can meet the requirements for electronics applications with increasing demand for higher energy and power densities and are considered as an ideal candidate for next-generation energy storage. [9][10][11][12][13][14] Besides, in contrast to the other energy sources of geothermal energy, tidal energy, wind energy, hydropower and solar energy, ZIHSCs are not limited by insufficient conversion efficiency and geographical regionality. [15][16][17][18][19] Specically, the Zn metal anode has material abundance, good electrical conductivity, eminent compatibility with water, low redox potential of −0.76 V vs. the standard hydrogen electrode and high theoretical capacity of 823 mA h g −1 , thus contributing to multiple merits of low cost, high safety, wide potential window, long cycle life and high energy capacity.…”

Microporous carbons derived from nitrogen-rich triazatruxene-based porous organic polymers for efficient cathodic supercapacitors

“…Notable examples include their use in gas separation and capture, catalytic processes, fuel cell technologies, energy storage, water treatment, as well as shielding electromagnetic interfaces. [37][38][39][40][41][42][43][44] As stated in the literature, the synthesis of porous carbonaceous materials possessing exceptional porosity and substantial surface area can be accomplished through chemical activation techniques, applicable to numerous polymer precursors. Notable examples of these polymers encompass CMPs, metal-organic frameworks (MOFs), porous aromatic frameworks (PAFs), and hypercrosslinked polymers (HCPs).…”