Thermally Activated Multilayered Carbon Cloth as Flexible Supercapacitor Electrode Material with Significantly Enhanced Areal Energy Density

Abstract

Carbon cloth, an inexpensive and conductive textile, holds great promise as substrate for constructing electrical double-layer capacitors due to its mechanical and electrochemical superiority. However, its widespread application is significantly hampered by the intrinsic low specific capacity. In this work, we demonstrate that the areal capacitance of commercial carbon cloth is raised for 800-folds by a direct thermal activation strategy. When evaluated as the symmetric supercapacitor electrodes, thermally activated carbon cloth (TACC) displays the outstanding performance with areal capacitance up to 3291 mF cm À 2 and the energy density of 740 μW h cm À 2 at a power density of 9000 μW cm À 2 . In addition, the TACC-based electrode reserves 95.2 % capacitance after 10,000 chargedischarge cycles in a neutral NaBF 4 electrolyte, showing outstanding cycle durability of the material. This work offers a foolproof and scalable method to prepare flexible electrode materials for wearable energy storage devices.

Ultrahigh Areal Capacity Hydrogen‐Ion Batteries with MoO3 Loading Over 90 mg cm−2

“…Faradaic electrodes that can simultaneously deliver high energy capacity comparable to batteries and rate capability comparable to supercapacitors, are highly demanded for electrical energy storage, but remain a grand challenge at the moment. [ 1–3 ] The rate capability of Faradaic electrodes is partially determined by the diffusion rate of charge carriers inside electrodes, which in turn depends on the choice of charge carriers. [ 4–6 ] Group IA alkali metal ions in the periodic table have been popularly employed as charge carriers for rechargeable batteries starting from lithium, sodium down to potassium.…”

Optimizing the micropore-to-mesopore ratio of carbon-fiber-cloth creates record-high specific capacitance

“…4 (d) and S2, considering that obvious pores were observed from the SEM images. The original CFC has a Type-V adsorption-desorption isotherm which proves the presence of mesoporous pores [8] . The BET surface area of the original CFC is 3.9 m 2 /g, probably due to the surface carbon slices.…”

“…The presence of micropores can significantly improve the material capacity, as the hydrated ions strip off the hydrated shells [ 16 , 31 ] or the hydrated shell deforms [ 15 , 32 ] into the micropores. The smaller space in micropores effectively reduces the dis- [11] 88 10 mV/s 0-1 Ag/AgCl thermally activated CC [8] 912 20 mA/cm 2 0-1 Ag/AgCl activated carbon cloths [10] 756 6 mA/cm 2 0 to −1 SCE treated carbon cloth [9] 2367 2.5 mA/cm 2 0 to −1 SCE NCNFs/CC [2] 608 1 mA/cm 2 0 to −1 SCE RGO/m-CC [4] 331 1 mA/cm 2 0-1 Ag/AgCl CFC-750-N-S [13] 362 0.5 mA/cm 2 0-1 Hg/HgO N-doped carbon cloth [1] 1200 8 mA/cm 2 0 to −1 SEC CQDs/PPy-50 [38] 516 10 mV/s 0.5 to −0.5 Ag/AgCl MnO2/graphene [39] 500 5 mV/s 0-0.8 Hg/Hg 2 Cl 2 MnO2@PANI@m-CC [40] 293.3 0.2 mA/cm 2 0-0.8 SCE MnO@C/CC [41] 716 4 mA/cm 2 0.5 to −0.6 Hg/HgO PANI/N-C/SS [42] 624 0.05 mA/cm 2 0-0.8 Ag/AgCl activated carbon fiber paper [43] 750 5 mA/cm 2 0 to −0.9 SCE This work 1324 2 mA/cm 2 0 to −1 SCE https://engine.scichina.com/doi/10.1016/j.jechem.2019.12.014 Table 2. The volumes of pores for CFC, 350CFC, 400CFC, 425CFC, 450CFC and 475CFC.…”

“…EDLC is originated from the electric double layer between electrode and electrolyte, in the form of both inner and outer surfaces of active materials [5][6][7] . Thus, expanding the specific surface area (SSA) of CFCs may be constructive to boost the specific capacitance and address the low energy density issues [8][9][10][11][12][13][14] . Nevertheless, no clear correlation between the specific capacitance and SSA has been found and the capacitance enhancement is still challenging [9] .…”

Flexible Solid‐State Symmetric Supercapacitors Using HxWO3@Reduced Graphene Oxide Composite with High Volumetric Energy and Power Densities

“…For that purpose flexible solid‐state supercapacitor is a promising energy storage device because of its easy fabrication, safety cum comfortably handle‐able, low price and presence of high volumetric energy and power densities . Recently several approaches are made to design high volumetric energy and power dense flexible solid state supercapacitors . Liu et al.…”