Novel Nonstoichiometric Niobium Oxide Anode Material with Rich Oxygen Vacancies for Advanced Lithium-Ion Capacitors.

Given the inherent features of open tunnel-like structures, moderate lithiation potential (1.0-3.0 V vs Li/Li), and reversible redox couples (Nb/Nb and Nb/Nb redox couples), niobium-based oxides with Wadsley-Roth crystallographic shear structure are promising anode materials.

Ultra-Low-Dose Pre-Metallation Strategy Served for Commercial Metal-Ion Capacitors.

Interfacial bonding strategy has been successfully applied to address the high overpotential issue of sacrificial additives, which reduced the decompositon potential of NaCO from 4.50 to 3.95 V.

Electronic Effect and Regiochemistry of Substitution in Pre-sodiation Chemistry.

The low oxidation potential of a pre-sodiation cathode additive intrinsically prevents decomposition of the electrolyte. Although the introduction of electron-donating substitution reduces the oxidation potential, the additional molecular weight restricts the output capacity. Herein, as theroretically predicted, the electrochemical oxidation potential of sodium carboxylate is manipulated by the electronic effect and regiochemistry of the functionality, in which the stronger electron-donating substituent, p-π conjugation, and optimized regiochemistry can dramatically lead to the lower potential originated from the elevation of the highest occupied molecular orbital level.

High content anion (S/Se/P) doping assisted by defect engineering with fast charge transfer kinetics for high-performance sodium ion capacitors.

The rate-determining process for sodium storage in TiO is greatly depending on charge transfer happening in the electrode materials owing to its inferior diffusion coefficient and electronic conductivity. Apart from reducing the diffusion distance of ion/electron, the increasement of ionic/electronic mobility in the crystal lattice is also very important for charge transport. Here, an oxygen vacancy (OV) engineering assisted in high-content anion (S/Se/P) doping strategy to enhance charge transfer kinetics for ultrafast sodium-storage performance is proposed.

Presodiation Strategies for the Promotion of Sodium-Based Energy Storage Systems.

Nowadays sodium-based energy storage systems (Na-based ESSs) have been widely researched as it possesses the possibility to replace traditional energy storage media to become next generation energy storage system. However, due to the irreversible loss of sodium ions in the first cycle, development of Na-based ESSs is limited. Presodiation, as a strategy of adding excess sodium ions to the system in advance, accomplishes the enhancement of electrochemical performance.

Insights into Enhanced Capacitive Behavior of Carbon Cathode for Lithium Ion Capacitors: The Coupling of Pore Size and Graphitization Engineering.

The lack of methods to modulate intrinsic textures of carbon cathode has seriously hindered the revelation of in-depth relationship between inherent natures and capacitive behaviors, limiting the advancement of lithium ion capacitors (LICs). Here, an orientated-designed pore size distribution (range from 0.5 to 200 nm) and graphitization engineering strategy of carbon materials through regulating molar ratios of Zn/Co ions has been proposed, which provides an effective platform to deeply evaluate the capacitive behaviors of carbon cathode.

Molecularly Compensated Pre-Metallation Strategy for Metal-Ion Batteries and Capacitors.

The use of a sacrificial cathode additive as a pre-metallation method could ensure adequate metal sources for advanced energy storage devices. However, this pre-metallation technique suffers from the precise regulation of decomposition potential of additive. Herein, a molecularly compensated pre-metallation (Li/Na/K) strategy has been achieved through Kolbe electrolysis, in which the electrochemical oxidation potential of a metal carboxylate is manipulated by the bonding energy of the oxygen-metal (O-M) moiety.

Correction: Highly stable zinc metal anode enabled by oxygen functional groups for advanced Zn-ion supercapacitors.

Correction for 'Highly stable zinc metal anode enabled by oxygen functional groups for advanced Zn-ion supercapacitors' by Kangyu Zou et al., Chem. Commun.

Electrochemically captured Zintl cluster-induced bismuthene for sodium-ion storage.

Bismuthene was prepared via the oxidation of Zintl clusters by electrochemical cathodic corrosion. It was found that the conversion of Zintl clusters from Bi to Bi occurred in the electrolyte having short alkyl chains due to the faster kinetics of highly reactive carbocation. Considering that c-NaBi exists in a wide voltage range, monitored by in situ XRD, a new wide peak for the as-obtained bismuthene in the CV curve was noticed, which benefits the improvement of electrochemical performances.

Highly stable zinc metal anode enabled by oxygen functional groups for advanced Zn-ion supercapacitors.

Konjac glucomannan (KGM) featuring abundant oxygen functional groups has been elaborately designed to enhance Zn reversibility. Importantly, -OH and C[double bond, length as m-dash]O groups as active sites could redistribute the Zn concentration field and modulate the plating/stripping rate, further enabling uniform Zn deposition without dendrite growth. The Zn@KGM anode enables an advanced Zn-ion supercapacitor to deliver an impressive rate performance and cycling stability (up to 5000 cycles accompanied by a coulombic efficiency of 99.

Defect Rich Hierarchical Porous Carbon for High Power Supercapacitors.

Tuning hierarchical pore structure of carbon materials is an effective way to achieve high energy density under high power density of carbon-based supercapacitors. However, at present, most of methods for regulating pores of carbon materials are too complicated to be achieved. In this work, a durian shell derived porous carbon (DSPC) with abundant porous is prepared through chemical activation as a defect strategy.

Quinone/ester-based oxygen functional group-incorporated full carbon Li-ion capacitor for enhanced performance.

Lithium ion capacitors (LICs) are regarded as one of the most promising energy storage devices since they can bridge the gap between lithium ion batteries and supercapacitors. However, the mismatches in specific capacity, high-rate behavior, and cycling stability between the two electrodes are the most critical issues that need to be addressed, severely limiting the large energy density and long cycling life of LICs while delivering high-power density output. Herein, quinone and ester-type oxygen-modified carbon has been successfully obtained by chemical activation with alkali, which is beneficial to the absorption of PF together with lithium ions, which would largely improve the electrode kinetics.

Controllable Syntheses of MOF-Derived Materials.

Metal-organic frameworks (MOFs), as an important kind of porous inorganic-organic hybrid materials with inherent outstanding physicochemistry characteristics, can be widely applied as versatile precursors for the facile preparation of functional MOF-derived materials. However, there are plenty of sophisticated factors during the synthetic process, which is far from reaching the goal of effectively controlling the nature of MOF-derived materials (such as the composition, morphology and surface area). Therefore, it is urgently necessary to develop regular protocols and concepts for controllable syntheses of MOF-derived materials.

Solvent-Induced Cadmium(II) Metal-Organic Frameworks with Adjustable Guest-Evacuated Porosity: Application in the Controllable Assembly of MOF-Derived Porous Carbon Materials for Supercapacitors.

In this work, five new cadmium metal-organic frameworks (Cd-MOFs 1-5) have been synthesized from solvothermal reactions of Cd(NO ) ⋅4 H O with isophthalic acid and 1,4-bis(imidazol-1-yl)-benzene under different solvent systems of CH OH, C H OH, (CH ) CHOH, DMF, and N-methyl-2-pyrrolidone (NMP), respectively. Cd-MOF 1 shows a 3D diamondoid framework with 1D rhombic and hexagonal channels, and the porosity is 12.9 %.

Benzoate Acid-Dependent Lattice Dimension of Co-MOFs and MOF-Derived CoS@CNTs with Tunable Pore Diameters for Supercapacitors.

Herein three novel cobalt metal-organic frameworks (Co-MOFs) with similar ingredients, [Co(bib)(o-bdc)] (1), [Co(bib)(m-bdc)] (2), and {[Co(bib)(p-bdc)(HO)](HO)} (3), have been synthesized from the reaction of cobalt nitrate with 1,4-bis(imidazol-1-yl)benzene (bib) and structure-related aromatic acids (1,2-benzenedicarboxylic acid = o-bdc, 1,3-benzenedicarboxylic acid = m-bdc, and 1,4-benzenedicarboxylic acid = p-bdc) by the solvothermal method. It is aimed to perform systematic research on the relationship among the conformation of benzoate acid, lattice dimension of Co-MOF, and pore diameter of MOF-derived carbon composite. Through the precursor strategy, Co-MOFs 1-3 have been utilized to synthesize porous cobalt@carbon nanotube composites (Co@CNTs).

Controlling the BET Surface Area of Porous Carbon by Using the Cd/C Ratio of a Cd-MOF Precursor and Enhancing the Capacitance by Activation with KOH.

Herein, four new cadmium metal-organic frameworks (Cd-MOFs), [Cd(bib)(bdc)] (1), [Cd(bbib)(bdc)(H O)] (2), [Cd(bibp)(bdc)] (3), and [Cd (bbibp) (bdc) (H O)] (4), have been constructed from the reaction of Cd(NO ) ⋅4 H O with 1,4-benzenedicarboxylate (H bdc) and structure-related bis(imidazole) ligands (1,4-bis(imidazol-1-yl)benzene (bib), 1,4-bis(benzoimidazol-1-yl)benzene (bbib), 4,4'-bis(imidazol-1-yl)biphenyl (bibp), and 4,4'-bis(benzoimidazol-1-yl)biphenyl (bbibp)) under solvothermal conditions. Cd-MOF 1 shows a 2D (4,4) lattice with parallel interpenetration, whereas 2 displays an interesting 3D interpenetrating dia network, 3 exhibits an unusual 3D interpenetrating dmp network, and 4 presents a 3D self-catenated pillar-layered framework with a Schäfli symbol of [4 ⋅6 ] ⋅[4 ⋅6 ⋅8 ]. The structural diversity indicates that the backbone of the bis(imidazole) ligand (including the terminal group and spacer) plays a crucial role in the assembly of mixed-ligand frameworks.

Hierarchically Flower-like N-Doped Porous Carbon Materials Derived from an Explosive 3-Fold Interpenetrating Diamondoid Copper Metal-Organic Framework for a Supercapacitor.

A peculiar copper metal-organic framework (Cu-MOF) was synthesized by a self-assembly method, which presents a 3-fold interpenetrating diamondoid net based on the square-planar Cu(II) node. Although it exhibits a high degree of interpenetration, the Cu-MOF still exhibits a one-dimensional channel, which provides a template for constructing porous materials through the "precursor" strategy. Furthermore, the explosive ClO4(-) ion, which resided in the channel, could induce the quick decomposition of organic ingredients and release a huge amount of gas, which is beneficial for the porosity of postsynthetic materials.

1D-3D mixed-ligand frameworks with an unusual dmp topology tuned by intersection angles of isomeric benzenedicarboxylates: magnetic properties, gas-dependent calcination-thermolysis and energy storage performances.

In this work, three isomeric benzenedicarboxylates, 1,2-benzenedicarboxylic acid (o-H2bdc), 1,3-benzenedicarboxylic acid (m-H2bdc), and 1,4-benzenedicarboxylic acid (p-H2bdc) have been utilized as the ancillary ligands to perform a systematic study on the structural diversity of mixed-ligand frameworks. The solvothermal reactions of Co(NO3)2 with these aromatic acids and the primary ligand 4,4'-bis(imidazolyl)biphenyl (bibp) afford three novel coordination polymers, {[Co6(bibp)3(o-bdc)6(H2O)](CH3CN)1.5}∞ (1), [Co(bibp)(m-bdc)]∞ (2), and [Co(bibp)(p-bdc)]∞ (3).