Advanced Functional Carbons and Their Hybrid Nanoarchitectures towards Supercapacitor Applications

Abstract

Porous carbons have attracted much attention as electrode materials for supercapacitors due to their enormous surface area, high electrical conductivity, excellent corrosion resistance, high temperature stability, and relatively low cost. The design of porous architectures is considered key for determining electrochemical performance. Pore size distribution, pore size, and pore connectivity strongly affect electrochemical performance. Various carbon materials with pore size ranging from micro- to macropores were extensively studied. Herein, various types of porous carbon-based and hybrid materials from different approaches and their electrochemical applications are summarized. Appropriate tuning of the pore size of carbon materials is essential for ensuring good transport of ions with different sizes throughout the electrolyte, so that the electrode materials can be fully utilized. Many carbon materials were produced from a series of carbonization and activation processes that possess controllable pore structures, including activated carbons, graphite, carbon nanotubes, carbon aerogels, and templated porous carbons. Templated carbon materials were prepared by various approaches, such as direct carbonization from carbon precursors and soft- and hard-template methods. To enhance the electrochemical performance of the electrode materials, heteroatoms, such as nitrogen, sulfur, and boron, were doped into porous carbons. In addition, to optimize the overall capacitance without destroying the stability and morphology of electrode materials, pseudocapacitive materials, such as transition-metal oxides, were introduced into the carbon frameworks. In this review, recent advances in the fabrication of nanoarchitectured porous carbons and metal oxides through various approaches for supercapacitor applications are summarized.

Biomass‐Derived Carbon: A Value‐Added Journey Towards Constructing High‐Energy Supercapacitors in an Asymmetric Fashion

“…The surfacea rea can be increased by increasing the porosity of the carbon material. [103] Commercial AC can offer as pecific capacitance of 70-200 Fg À1 in aqueous electrolytes. Importantly,P SD andt uning the porosity of carbon materials have asignificant role in the capacitance.…”

“…Among them, AC stands out because of its large surfacea rea (> 1000 m 2 g À1 ), large pore volume (> 0.5 cm 2 g À1 ), and relativelyl ow cost. [103] As their performance is affected by PSD and internal resistance. Similar to battery applications, the cost of the active material used in the electrode is also al imitingf actor for SC applications.…”

“…Similar to battery applications, the cost of the active material used in the electrode is also al imitingf actor for SC applications. [103] Different porous templates can be used for the synthesis of carbon materials with suitable distributions of meso-and macropores.A ctivation is another methodu sed to control porosity, which can increase micropored istribution. Other factors, such as the time and temperature of the activation step, have arole in fixing the PSD.…”

Gel–Emulsion‐Templated Polymeric Aerogels for Water Treatment by Organic Liquid Removal and Solar Vapor Generation

“…Among materials used in water purification, porous materials have attracted extensive attention because of their low density, high porosity, and large specific surface area . A series of porous materials has been developed, and many have been proven to be efficient in water purification .…”

Metal–Organic Framework (MOF)‐Derived Nanoporous Carbon Materials

“…These outstanding properties make them attractive for various applications, such as environmental remediations, energy storage systems (i.e. batteries, supercapacitors), and as catalysts . To date, various carbon materials with different pore sizes, from micropores to macropores, have been extensively studied.…”