Silica-Assisted Controlled Engineering of Nitrogen-Doped Carbon Cages with Bulges for High-Performance Supercapacitors

Abstract

The bulge structure of N-doped carbon cages is beneficial to improving the specific surface area and increasing the active sites of a chemical reaction. Therefore, this structure plays a role in increasing capacity in energy storage. However, the precise and most effective method of ensuring the bulge structures is still a challenge. Herein, a silicaassisted method is used to prepare N-doped carbon cages with bulges. The effective assembly of a nitrogen-rich resin and silica precursor is employed to construct the bulge structure on the surface. The reaction temperature of the assembly system and the amount of silica precursor are the key influences on the number and degree of bulges. In contrast to conventional carbon materials that have a smooth surface, the bulge structure allows for exposure and accessibility of the activity sites. Due to the N-doping features, a rich mesoporous structure and controllable bulges, the synergism of the high density, large ionaccessible surface area, and fast charge transfer, lead to high performance under the premise of high rate capability in supercapacitor. This silica-assisted strategy can also work on other preprepared corresponding templates that have a different architecture to prepare core−shell carbon tubes, carbon spheres, and carbon rods with a bulge structure.

Facile and Tunable Synthesis of Nitrogen-Doped Graphene with Different Microstructures for High-Performance Supercapacitors

“…Accordingly, the corresponding Ragone plot is displayed in Figure d, which shows the highest energy density is 14.6 Wh kg –1 at a power density of 252.3 W kg –1 , and the highest power density is 9000 W kg –1 at 12.5 Wh kg –1 . The obtained results are highly competitive or comparable to many of the N-doped carbon-based supercapacitor devices in literatures. − The stability of the BNG-based supercapacitor was also evaluated at a current density of 10 A g –1 (Figure e). The supercapacitor demonstrates a superb long-term cycling stability with a capacitance retention of 96% over 10,000 cycles.…”

Spatial Confinement Strategy for Micelle-Size-Mediated Modulation of Mesopores in Hierarchical Porous Carbon Nanosheets with an Efficient Capacitive Response

“…Commercial supercapacitor systems relying on rapid ion-adsorption behaviors of the electrolyte layer and the activated carbon surface are sustainably popularized for instant energy storage and mobile power supply, as the energy can be reversibly harvested/delivered in seconds. − Characterized by a prominent specific surface area (SSA), commercial carbon electrodes are highly valued for their surface energy-storage mechanisms because the extensive adsorption space within carbons can guarantee a high storage capacity of electrolyte ions. , Actually, most of the supercapacitors utilizing commercial carbon products display an unsatisfactory specific capacitance and energy delivery because of poor SSA utilization, which hinders the system development with an ever-growing energy requirement. − The SSA parameter measured in a gaseous atmosphere cannot accurately characterize the electrolyte-accessible carbon surface in an electrochemical environment. For instance, commercial activated carbon contains a large portion of small-sized pores (<0.5 nm) whose diameter is too small to provide ion adsorption sites, and the consequent under-utilization of the surface blocks the formation of electrochemical double layers. − Inefficient diffusion pathways within activated carbons also result in a lower ion-transport efficiency and slower capacitive response, especially in high-rate electrochemical shuttles, which downgrades the inherent high-rate delivery and long-cycle tolerance .…”

A study on the pesticides-loading capacity of dendritic fibrous nano silica synthesized from 1-pentanol-water microemulsion with a low oil-water ratio

“…Mesoporous silica nanoparticles (MSN) have garnered significant attention due to their large surface area, customizable pore size, modifiable surface, robust thermal and chemical stability, and excellent biocompatibility [8]. MSN has overcome the pore size limitations of microporous materials, resulting in widespread use in various fields, including catalysis [9,10], adsorption separation [11][12][13], molecular detection [14], supercapacitors [15], drug delivery [16,17], and biomedical applications [18][19][20][21][22][23]. Additionally, the numerous silicon hydroxyl groups on the surface of MSN can be used to create novel assembly materials [24].…”