Synthesis Strategies of Porous Carbon for Supercapacitor Applications

Abstract

Supercapacitors (SCs) have experienced a significant increase in research activity and commercialization during the past few decades. As the primary and most important electrode active material for commercial SCs, porous carbon is produced at an industrial‐scale through traditional carbonization‐activation strategies. Nevertheless, commercial porous carbon materials have some disadvantages such as high production cost, corrosion of equipment, and emission of toxic gases and byproduct pollutants during production. In recent years, huge efforts have been made to develop novel synthesis strategies for porous carbon materials. This review focuses on the pore formation mechanisms in traditional carbonization‐activation methods, emerging activation methods, template methods, self‐template methods, and novel emerging methods for the synthesis of porous carbons for SCs. Strategies developed so far for the synthesis of porous carbon materials are summarized. The mechanisms and recent advances for each strategy are reviewed. Furthermore, future directions and synthesis strategies for porous carbons are proposed.

Asymmetric Supercapacitors Based on Hierarchically Nanoporous Carbon and ZnCo2O4 From a Single Biometallic Metal-Organic Frameworks (Zn/Co-MOF)

“…At the current density of 0.5 A/g, the specific capacitance of ZnCo 2 O 4 , NPC, and C@ZnCo 2 O 4 is 420, 270, and 173 F/g. Obviously, the capacitance of NPC is higher than most carbons (Bi et al, 2019 ; Yin et al, 2020 ). In addition, the capacitance performance of ZnCo 2 O 4 is much better than that of C@ZnCo 2 O 4 , because the latter contains a large amount of organic carbons that reduces its conductivity, resulting in poor electrochemical performance.…”

Electrochemical Zinc Ion Capacitors Enhanced by Redox Reactions of Porous Carbon Cathodes

“…[ 1 ] Among various rechargeable batteries and supercapacitors, aqueous electrochemical energy storage systems are preferred due to their high safety and low capital cost. [ 2 ] However, commercial aqueous lead‐ and nickel‐based rechargeable batteries possess low energy densities (≈45 Wh kg −1 for Pb–acid batteries; [ 3 ] ≈50 Wh kg −1 for Ni–Cd batteries [ 4 ] ) and limited life spans, which increases the energy storage cost per unit energy output, [ 5,6 ] thus limits their practical applications. Zinc metal is considered as an ideal anode for aqueous energy storage devices because of its high theoretical capacity (gravimetric, 820 mAh g −1 ; volumetric, 5851 mAh cm −3 ), low potential (−0.76 V vs standard hydrogen electrode (SHE)), and high hydrogen evolution overpotential.…”

Recent advances in carbon-based supercapacitors

“…Besides, the simultaneous carbonization-activation process was considered to be another noteworthy template-free approach for the construction of 3D interconnected macrostructures because of the high-temperature decomposition of organics in alkaline media. [114][115][116][117][118] As a typical example, Fan's group reported the one-step pyrolysis of KOH-assisted wheat flour to obtain interconnected honeycomb-like porous carbons. 119 The alkalitreated flour gelatin as the self-porogen could undergo a series of stages such as framework decomposition, volume expansion, and intermediate foaming during annealing to form hierarchical porous structures.…”