Ultrafast Porous Carbon Activation Promises High‐Energy Density Supercapacitors

Abstract

Activated porous carbons (APCs) are traditionally produced by heat treatment and KOH activation, where the production time can be as long as 2 h, and the produced activated porous carbons suffer from relatively low specific surface area and porosity. In this study, the fast high‐temperature shock (HTS) carbonization and HTS‐KOH activation method to synthesize activated porous carbons with high specific surface area of ≈843 m2 g‐1, is proposed. During the HTS process, the instant Joule heating (at a heating speed of ≈1100 K s‐1) with high temperature and rapid quenching can effectively produce abundant pores with homogeneous size‐distribution due to the instant melt of KOH into small droplets, which facilitates the interaction between carbon and KOH to form controllable, dense, and small pores. The as‐prepared HTS‐APC‐based supercapacitors deliver a high energy density of 25 Wh kg‐1 at a power density of 582 W kg‐1 in the EMIMBF4 ionic liquid. It is believed that the proposed HTS technique has created a new pathway for manufacturing activated porous carbons with largely enhanced energy density of supercapacitors, which can inspire the development of energy storage materials.

Defect engineering in carbon materials for electrochemical energy storage and catalytic conversion

“…Meanwhile, carbon-based electrodes with hierarchical pores have attracted much attention in recent years. [86][87][88][89] In terms of the types of porous carbon materials used in porous electrodes, porous activated carbon, 90,91 porous carbon nanotubes, 92,93 porous graphene [94][95][96] and porous conductive polymers show great potential for energy storage and conversion applications. In general, the research related to porous electrodes has made great progress and the applications will become more and more widespread.…”

3D nanoflower-like and core–shell structured MCo2O4@MCo2S4@polypyrrole (M = Cu, Mn) composites as supercapacitor electrode materials with ultrahigh specific capacitances

“…The development of efficient, renewable, sustainable and green energy storage and conversion technologies has become the key to settling the problem of continued fossil fuel consumption and energy demand. 1,2 Thus, electrochemical devices including water splitting devices, 3,4 electrochemical biosensors, 5,6 secondary batteries 7,8 and supercapacitor (SC) devices 9,10 have attracted enormous attention from materials scientists worldwide. SCs are emerging as novel energy storage devices, which can offer fantastic advantages, including good reversibility, longer cycling lifespans, shorter charge times and environmentally friendly properties.…”

Reconfiguring the Electronic Structure of Heteroatom Doped Carbon Supported Bimetallic Oxide@Metal Sulfide Core–Shell Heterostructure via In Situ Nb Incorporation toward Extrinsic Pseudocapacitor

“…[6,8,11,12] Though, the polarization phenomenon of these materials hinders the charge transportation, which leading to sluggish electron transfer, slow ion diffusion, and inadequate rate capabilities. [13][14][15] The heteroatom doped lattice distorted, defects and vacancy rich metal-organic framework (MOF)-derived transition metal chalcogenides (TMDs) have unique electronic structures with a 3D scaffold skeleton, district porous geometric structures, and weak interlayer van der Waals coupling. [16] Additionally, the coating of metal atom doped abundant redox active sides of transition metal oxides (TMOs) of cobalt molybdate on heteroatom doped cobalt sulfide TMDs (CMO 4 @C x S y NC) can significantly improve the charge storage capacity and cycling stability by preventing deterioration of the inner core material.…”