Facile synthesis of bowl-shaped nitrogen-doped carbon hollow particles templated by block copolymer “kippah vesicles” for high performance supercapacitors

Abstract

This paper reports a simple self-assembly strategy towards bowl-shaped carbon-containing hollow particles, as well as an unprecedented potential application for block copolymer vesicles in energy storage.Kippah vesicles (fully collapsed vesicles), formed by solution self-assembly of an amphiphilic polystyreneblock-poly(ethylene oxide) block copolymer, were employed as the template to guide the formation of bowl-shaped nitrogen-doped carbon hollow particles (BNCHPs). As electrode materials of supercapacitors, BNCHPs exhibit superior electrochemical performance. In particular, compared with their spherical counterpart, BNCHPs largely increase their volumetric packing density, leading to much higher volumetric capacitance or volume reduction of electrodes, which is desired for practical supercapacitor devices. † Electronic supplementary information (ESI) available: ESI figures and tables.

Anisotropic polydopamine capsules with an ellipsoidal shape that can tolerate harsh conditions: efficient adsorbents for organic dyes and precursors for ellipsoidal hollow carbon particles

“…8B) Compared to their spherical counterparts, capsules with an ellipsoidal or other non-spherical shape have many additional advantages such as enhanced cargo loading efficiency for drug delivering, improved cell uptake in the cases of cancer treatment and enhanced packing efficiency in solid materials as indicated by previous works. [13][14][15] Relative to the current work, we think the advantage of enhanced packing efficiency in solid materials is very benecial. In the format of dried powders in which particles are randomly packed, ellipsoidal particles can randomly pack more densely and achieve a volume fraction (4) up to 0.74, higher than 0.64 of spherical ones.…”

“…4,6,7,9,10,[22][23][24][25] Furthermore, polymeric capsules oen need to be processed into other materials in the dried state and under high temperature and pressure. 15,26,27 Keeping the intactness of their precious capsule-like shape is demanding during such stringent processes since the loss of the shape unavoidably devalues the advantages brought by the hollow cavity, and high specic surface area. For instance, highly charged spherical polystyrene capsules were dried into three dimensional colloidal crystals that can be used as photonic crystals for chemical sensing by the change of the structure color.…”

“…5,6,[8][9][10][11][12] It is noted that most of PDA capsules prepared so far have a spherical shape, [4][5][6][7]11 while non-spherical ones may have additional advantages in cargo loading, cell uptake and enhanced packing efficiency in energetic materials. [13][14][15] However, preparation of non-spherical polymeric capsules is generally challenging.…”

Designing Carbon Based Supercapacitors with High Energy Density: A Summary of Recent Progress

“…In contrast, the soft-template method refers to utilizings elfassembled soft templates to obtain porous structure through condensation and carbonization.S omee asily removed templates are also employed in soft-template systems, such as emulsion droplets, [56] micelles, [57] vesicles, [58] and gas bubbles, [59] which usually originate from additives like polymers and surfactants. For examples, Zhang, with his co-authors, [60] employed as elf-assembled soft-template to obtain MXene-derived layer-by-layer ordered mesoporous carbon, based on phenol-formaldehyde resol as carbon source.T he as-fabricated ordered mesoporous carbon (OMC) electrode showed excellent specific capacitance of 240 Fg À1 at 1Ag À1 even with ah igh mass loading of 12 mg cm À2 .M ore importantly,t he assembled symmetric CSCs exhibited an outstanding capacitance of 162 Fg À1 at 1Ag À1 in 6 m KOH electrolyte.…”

Role of High‐Molecular‐Weight Homopolymers on Block Copolymer Self‐Assembly: From Morphology Modifier to Template

“…Amphiphilic block copolymers (BCPs) are capable of self‐assembling into diverse nanostructures in selective solvents . Tuning morphology of the assembled aggregates becomes one of the key topics for BCPs self‐assembly research, since the morphology of the self‐assembled aggregates influences their properties and application performance .…”