Facile self-templating large scale preparation of biomass-derived 3D hierarchical porous carbon for advanced supercapacitors

Abstract

Routine or incremental work, however competently researched and reported, should not be recommended for publication if it does not meet our expectations with regard to novelty and impact.It is the responsibility of authors to provide fully convincing evidence for the homogeneity and identity of all compounds they claim as new. Evidence of both purity and identity is required to establish that the properties and constants reported are those of the compound with the new structure claimed.Thank you for your effort in reviewing this submission. It is only through the continued service of referees that we can maintain both the high quality of the publication and the rapid response times to authors.Corn husk, a renewable biomass, has been successfully explored as low-cost crude carbon source to prepare advanced higher-value 3D HPCs by means of KOH pre-treatment and direct pyrolysis, and the route is simple, self-template and easy to implement scale-up for industrialization. The CHHPCs present many advantages for supercapacior application, including higher surface area (928 m 2 g -1 ), hierarchical porosity consisting of macro, meso, and micropores, turbostratic carbon structure, uniform pore size, 3D architecture and rich O-doping (17.1 wt%). The supercapacitor performance of CHHPCs was evaluated in 6 M KOH electrolyte and 1 M Na 2 SO 4 electrolyte. The CHHPCs exhibits a high specific capacitance of 356 F g -1 and 300 F g -1 at 1 A g -1 , 20 A g -1 , respectively, ultra-high rate capability with 88% retention rate from 1 to 10 A g -1 and outstanding cycling stability with 95% capacitance retention after 2500 cycles. The CHHPCs symmetric supercapacitor displays a high energy density of 21 Wh kg -1 at a power density of 875 W kg -1 and retains as high as 11 Wh kg -1 at 5600 W kg -1 in 1M Na 2 SO 4 electrolyte. The facile, efficient and template-free synthesis strategy for novel 3D-HPCs from biomass sources may promote commercial application of 3D-HPCs in the fields of supercapacitors, lithium ion batteries, fuel cells and sorbents.

Activated Carbon Fibers with Hierarchical Nanostructure Derived from Waste Cotton Gloves as High-Performance Electrodes for Supercapacitors

“…4b, numerous micropores and small mesopores are concentrated at 1.3 and 2.7 nm, respectively, consisting with the TEM observation. It is believed that the KOH activation not only creates a substantial number of micropores but also continues widening them into small mesopores [21, 35, 36]. Comparatively, the commercial AC only shows an uptake at low P / P 0 , suggesting a micropore peak at 1.3 nm (Fig.…”

Recent progress in carbon-based nanoarchitectures for advanced supercapacitors

“…Compared to conventional porous carbon materials, 3D carbon-based nanostructures possess hierarchical porous paths, superior electrical conductivity, and stable structural mechanical property. Moreover, the 3D nanoscale designs could not only deliver continuous electron paths to guarantee excellent electrical accessibility, but also accelerate ion transfer through shortening diffusion paths in 3D hierarchical porous nanostructures with different wellinterconnected pore models, which can be acceptable for high-performance electrode materials of SCs [110,136]. Hence, it is advisable to design and fabricate novel 3D carbon-based nanostructures by integrating the benefits of various carbon building blocks.…”

“…The interconnected hierarchical porous structure could shorten the ion diffusion distances as well as offer large specific surface area to enhance ion accessibility [136,137]. The adequate pore size and shape of carbon materials play the decisive roles in their ultimate performances, and both larger and smaller pores would lead to an evident decline in capacitive performances owing to the ion-sieving effect.…”

“…Recently, researchers have made enormous efforts to obtain numerous porous carbons from low-cost renewable biomass sources. For example, Wan et al [136] prepared advanced higher-value 3D HPCs through the carbonization of the KOH-pre-treated corn husks. In the pre-treated process, KOH not only acted as the pre-treated agent to separate cellulose from hemicellulose and lignin in corn husk, but also served as the activating agent to develop the hierarchically interconnected pore network structure.…”

Biomass Inspired Nitrogen Doped Porous Carbon Anode with High Performance for Lithium Ion Batteries

“…[18][19][20] The preparation of porous carbon materials always involves the silica template method, chemical activation (KOH, H 3 PO 4 and ZnCl 2 ) method, spray pyrolysis, electrospinning-carbonization using precursors of melamine and polyacrylonitrile, ice-templating-carbonization of polyacrylonitrile precursor and so on. [21][22][23][24][25][26][27][28] However, most of the fabrication methods need high-cost reagents, special equipment or complex process control. Therefore, it is necessary to develop a simple and low cost approach to fabricate porous carbon with appropriate heteroatom doping and satisfactory electrochemical performance in the application of lithium ion batteries.…”