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N/O self-doped hollow carbon nanorods (HCNs) with micro/mesoporous walls are fabricated based on a new deep-eutectic-solvent that serves as an all-in-one precursor, self-template, and self-dopant agent. The carbon-based supercapacitor using an ionic liquid electrolyte exhibits a high energy density of 116.5 W h kg−1 with excellent long-term cycling performance. [ABSTRACT FROM AUTHOR]

Keywords: carbon superstructures; Lewis pair interactions; self-assemblies; zinc-ion storages EN carbon superstructures Lewis pair interactions self-assemblies zinc-ion storages 1 1 1 11/29/22 20221124 NES 221124 B Lewis Pair Interactions b In article number 2208049, Mingxian Liu and co-workers develop a Lewis pair self-assembly strategy to customize carbon superstructures, triggered by the interactions between ferric chloride (FeCl SB 3 sb , Lewis acid) and I p i -phenylenedimethanol (Lewis base) through H-bonding and - stacking. Carbon superstructures, Lewis pair interactions, zinc-ion storages, self-assemblies Lewis Pair Interaction Self-Assembly of Carbon Superstructures Harvesting High-Energy and Ultralong-Life Zinc-Ion Storage (Adv. Funct. [Extracted from the article]

Despite great advances in carbon synthesis through solution chemistry, a long-standing question is how to choose solvents effectively. Herein, we establish a systematical strategy to answer this question, guided by both the difference of total Hansen solubility parameter and the relative energy difference between the solvent and the precursor. This approach can quickly and accurately screen out the "excellent" solvent or solvent mixture from a lot of possible candidates including single, binary and multicomponent systems to synthesize carbon materials with optimal nanostructure and high surface area. We further find it is convenient to get a series of "excellent" solvents by mixing different grades of solvents ("poor", "fair", and "good"). This finding gives more opportunities for solvent choice to fabricate well-designed carbons, and also provides an economic and eco-friendly synthetic route by selecting cheap, low- or non-toxic solvents. The robust strategy, which has been applied to different carbon precursors, has already succeeded as a proof of concept. As-synthesized carbons feature sphere-like superstructure and high surface area, delivering fast electrochemical kinetics, ultrahigh energy density and excellent high-rate lifespan in energy storage applications. We establish a systematical strategy to quickly and accurately screen out the excellent solvents from a series of candidates including single, binary and multicomponent system to synthesize optimized carbons for efficient energy storage. [Display omitted] [ABSTRACT FROM AUTHOR]

Pore–ion size matching between carbon electrodes and electrolytes is crucial for superior energy storage. However, it remains a great challenge to engineer carbons with perfectly compatible pore dimension for desired electrolytes. Herein we design a simple synthetic route to obtain carbon hydrangeas integrated with unique geometry, high surface areas, N/O doping, and more importantly, well-developed pore structure. The narrow primary subnanopores of 0.80 nm are exactly matched the cation sizes (EMIM+, 0.76 nm) of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIMTFSI) and 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF 4) ionic liquid electrolytes. Besides, the secondary pores of 0.50 nm are size-exclusively accessible for small BF 4 − anions (0.48 nm) but exclude larger TFSI− (0.79 nm), giving enhanced ion diffusion/adsorption kinetics. The solid-state supercapacitor based on EMIMBF 4 gel electrolyte achieves an ultrahigh specific energy of 101.2 Wh kg−1 (29.2% enhancement against the use of EMIMTFSI), superior to the most values of recently reported carbon-based supercapacitors. This study opens new horizons to develop functionalized carbons with perfectly ion-comparable pore architecture, moving toward advanced energy storage systems. Pore–ion size matching criterion is implemented to engineer N, O codoped carbon hydrangeas with perfectly compatible pore dimension for ionic liquid gel electrolytes towards advanced solid-state supercapacitors. Image 1 • A novel and highly efficient design of N, O codoped carbon hydrangeas is demonstrated. • Carbon hydrangeas show perfectly compatible pore dimension with ionic liquid electrolytes. • Pore–ion size matching criterion achieves state-of-the-art solid-state supercapacitors. [ABSTRACT FROM AUTHOR]

We develop a novel self-doped and self-template strategy to synthesize N, S doped porous carbon nanosheets (N/S-HCSs) by pre-carbonization and post-activation of a low-cost protic salt of p -phenylenediamine toluenesulfate ([pPD][2CH 3 PhSO 3 ]). [pPD][2CH 3 PhSO 3 ] is obtained by a simple neutralization reaction at room temperature and behaves as an “all-in-one” precursor, serving as C, N, S sources and a self-template. As-prepared N/S-HCSs possess large specific surface area and nanosheet geometry which provide enough adsorbing sites for charge accumulation and shorten diffusion distance of electrolyte ions at electrode/electrolyte interface. Besides, N/S-HCSs exhibit unique porous nanoarchitecture with uniform ultramicropores and a well-developed network of supermicropores and mesopores, which guarantees highly efficient ion-highways for electrolyte diffusion and transport. Furthermore, incorporated heteroatoms in the carbon framework structure improve the electrical conductivity and surface wettability, and provide extra pseudocapacitance. As a result, N/S-HCS electrode delivers superior electrochemical performance including high gravimetric capacitance (280 F g −1 at 1.0 A g −1 ), good rate performance (134F g −1 at 50 A g −1 ) and cycling stability (94.4% retention after 10,000 cycles at 2.0 A g −1 ) in 6 M KOH electrolyte. The present innovative synthetic concept can be easily implemented, without complicated procedure and particular template, and thus opens up a new window towards the simple and highly efficient synthesis of well-designed carbon-based materials for supercapacitor applications. [ABSTRACT FROM AUTHOR]

We design a novel solvent- and self-template strategy to fabricate carbon materials with ultramicro-, supermicro- and mesopores through a simple solvothermal reaction of phloroglucinol and terephthaldehyde in dioxane using acetic acid as the catalyst, followed by carbonization. Dioxane serves simultaneously as a solvent in the reaction system and a template to generate mesopores (3.6 nm). Meanwhile, phloroglucinol/terephthaldehyde polymeric organic frameworks act as a self-template to produce regular and well-developed ultramicropores (0.54 nm) and some supermicropores (0.86 and 1.3 nm) during carbonization. High specific surface area (1003 m 2 g −1 ) coupled with hierarchical porous structure endow the resultant carbon electrode excellent electrochemical properties including a satisfactory specific capacitance (214 F g −1 at 1.0 A g −1 ), excellent rate capability (154 F g −1 at a very high current density of 50 A g −1 ) as well as superb long-term cycling stability (95.5% retention of initial capacitance after 10000 cycles) in alkaline electrolyte. Compared with traditional synthetic strategy for porous carbons, the present approach can be easily carried out, avoiding tedious procedure, customized hard/soft template or extra activation step, and thus highlights new opportunities towards the simple and highly efficient synthesis of well-designed porous carbons for supercapacitor applications. [ABSTRACT FROM AUTHOR]

We demonstrate a novel and efficient approach to fabricate reduced graphene oxide (RGO)/MnO x @carbon hollow nanospheres (HCNs) nanohybrids for high performance supercapacitor application. Mn 2+ ions can bind with negatively charged O atoms on graphene oxide (GO) via electrostatic forces to generate RGO/MnO x ( x ⩽ 2) under hydrothermal condition. This process was utilized to grow MnO x layers on the surfaces of RGO, and the RGO/MnO x was encapsulated within the outer carbon shell to obtain RGO/MnO x @HCNs. RGO/MnO x @HCNs have a regular hollow structure with uniform outer shells (∼10 nm) and inner spherical pores (∼150 nm), high surface areas (493–668 m 2 g −1 ), and high contents of MnO 2 (12.2–19.6 wt%). As-designed ternary core–shell 3D nanoarchitecture prevents the leaching of loaded manganese oxides and avoids the aggregation of RGO within the carbon shell, which effectively guarantees the electrochemical activity of each electroactive components. Consequently, a typical RGO/MnO x @HCNs as a supercapacitor electrode exhibits a high specific capacitance (355 and 270 F g −1 in a three-electrode and two-electrode system at 1.0 A g −1 , respectively) in 6 M KOH electrolyte. Besides, the electrode shows a high rate charge–discharge capability (20.0 A g −1 ), and good electrochemical stability (88% capacitance retention after 5000 cycles at 0.5 A g −1 ). The results suggest that the core–shell RGO/MnO x @HCNs nanostructures provide promising prospects for electrochemical energy storage applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Crystal splitting growth and self-assembly of carbon superstructures is proposed. • Carbon superstructures harvest superb energy density and cycling stability. • The alternate uptake of opposite charges occurs in superstructural carbon cathodes. The sluggish ion-migration kinetics and structural instability are critical limits of isolated single-level carbon structures, inhibiting capacitive activity and durability of Zn-ion capacitors. To conquer the roadblocks, making well-defined arrangement of low-dimensional building blocks into integrative carbon superstructures gives a promising solution, but remains challenging. Herein, we report a crystal splitting growth and self-assembly strategy to customize nanorod-integrated carbon superstructures for activating superior Zn-ion storage. The coordination between 3-aminobenzoic acid as an organic linker and Cu2+ as a metal node triggers the crystal splitting growth of polymeric clusters to yield nanorod modules, which further couple with 4,4′-bipyridine to self-assemble into exquisite superstructures. Featured with well-arranged one-piece topographies and beneficial diheteroatomic attributes, the robust carbon superstructures empower fast ion transport and easy accessibility of zincophilic sites with low energy barriers. The fabricated Zn-ion capacitors thus deliver ultrahigh energy density (157 Wh kg−1) and extraordinary cyclability (300,000 cycles@20 A g−1). Systematic studies identify the root of excellent electrochemical metrics as high-kinetics alternately physical uptake of Zn2+/SO 4 2− charge carriers and multielectron chemical redox reaction of pyridine/carbonyl motifs with Zn2+ to form N−Zn−O bonds. This work provides new avenues to engineer carbon superstructures for propelling advanced energy storage. [ABSTRACT FROM AUTHOR]

In this paper, we report a facile and novel synthesis of nitrogen-containing ultramicroporous carbon nanospheres (N-UCNs) for high performance supercapacitor electrodes. Phloroglucinol and terephthalaldehyde are polymerized to obtain polymer nanoparticles with a mean diameter of ∼15 nm. Hexamethylenetetramine (HMTA) is utilized to substitute ammonia and formaldehyde to polymerize with resorcinol on the surfaces of the polymer colloids for the fabrication of carbon spheres under the Stöber condition. The introduction of phloroglucinol/terephthalaldehyde brings regular ultramicroporous (0.58 nm) to the typical N-UCNs. Besides, the polymerization of resorcinol and HMTA on the surfaces of polymer nanoparticles reduces the diameter of carbon nanospheres from submicrometer sizes to nanoscaled sizes (∼36 nm). Furthermore, the NH 4 + released from the hydrolysis of HMTA also acts a source of nitrogen in the carbon framework (1.21 at.%), which can improve the surface properties and electric conductivity of N-UCNs. The typical N-UCNs (N-UCN 4.50 ) with spherical geometry, high surface area (1439 m 2 g −1 ), regular ultramicropores and nitrogen functional groups shows excellent electrochemical performance such as high specific capacitance (269 F g −1 at 1.0 A g −1 ), long-term cycle stability (90.3% retention after 10000 charge/discharge cycles) in 6 M KOH aqueous electrolyte. This finding provides new opportunities for well-designed carbon nanospheres to achieve advanced supercapacitor electrodes. [ABSTRACT FROM AUTHOR]

• Core-shell carbon spheres are fabricated based on the dynamic Schiff-base chemistry. • The compact π-conjugated polymer shell enhances the architecture robustness to withstand the pyrolysis/hybrid modification. • A high ion-matching/adsorbing interface and hierarchical diffusion shortcuts contribute to high-energy storage. • MnO 2 deposited on the robust carbon architecture paves another way toward efficient energy storage. Cost-effective synthesis of core-shell carbon spheres for supercapacitor applications remains a challenge. N/O codoped hierarchical porous carbon spheres with the core-shell architecture (MPG 2) are fabricated based on the dynamic Schiff-base chemistry free from any templates or complicated procedures. The nanoarchitectures of carbon materials are strongly determined by the addition of glyoxal which not only plays a key role in guiding the reassembly of dynamic imine intermediates to construct a stable core-shell architecture, but also endows carbon spheres with high mechanical strength/stability for the pyrolysis/hybrid modification due to the compact π-conjugated polymer shell. Benefiting from diffusion highways in hierarchical porous structure, a high ion-matching/adsorbing shell surface (1514 m2 g–1) with abundant micropores (0.5–0.8 nm) and N/O functionalities, the resultant MPG 2 -based symmetric supercapacitor using the lithium bis(trifluoromethane sulfonyl)imide electrolyte (the size of Li+/TFSI– is 0.069/0.79 nm) yields the large energy storage of 31.6 Wh kg–1 at 550 W kg–1 under the high aqueous voltage of 2.25 V, accompanied with a well-behaved cycling stability (capacitance retention of 86.2% over 10,000 rounds at 1 A g−1) and broad temperature applicability from 20 to 80 °C. Furthermore, MnO 2 is further deposited on the robust MPG 2 architecture to obtain the MPG 2 /MnO 2 composite as a positive electrode in the asymmetric device, and the overlapped voltage window of the MPG 2 /MnO 2 composite and the capacitive MPG 2 paves another efficient avenue toward a high energy-power aqueous device of 43.74 Wh kg–1 at 450 W kg–1. Image, graphical abstract [ABSTRACT FROM AUTHOR]