A facile one-step template-free method based on a novel inside-out Ostwald ripening mechanism is developed for inexpensive mass preparation of hollow and core/shell-type SnO2 nanostructures using potassium stannate as the precursor. As-prepared nanospheres (see figure) exhibit ultrahigh lithium storage capacity improved cycle performance high-energy anode materials in lithium-ion secondary batteries. Supporting information this article available WWW under...

Graphene has aroused intensive interest because of its unique structure, superior properties, and various promising applications. nanostructures with significant disorder defects have been considered to be poor materials lower their electrical conductivity. In this paper, we report that highly disordered graphene nanosheets can find applications in high-capacity Li ion batteries exceptionally high reversible capacities (794−1054 mA h/g) good cyclic stability. To understand the storage...

Conjugated polymeric molecules have been heralded as promising electrode materials for the next-generation energy-storage technologies owing to their chemical flexibility at molecular level, environmental benefit, and cost advantage. However, before any practical implementation takes place, low capacity, poor structural stability, sluggish ion/electron diffusion kinetics remain obstacles that be overcome. Here, we report synthesis of a few-layered two-dimensional covalent organic framework...

Abstract A Li‐air battery could potentially provide three to five times higher energy density/specific than conventional batteries and, thus, enable the driving range of an electric vehicle be comparable gasoline vehicles. However, making rechargeable presents significant challenges, mostly related materials. Here, key factors that influence rechargeability are discussed with a focus on nonaqueous systems. The status and materials challenges for reviewed. These include electrolytes, cathode...

The preparation of SnO2 nanotubes with coaxially grown carbon nanotube overlayers good conformal control shape and size is reported. SnO2-core/carbon-shell (see Figure) are excellent reversible lithium-ion storage compounds combining the best features (for cyclability) capacity). These structures deliver high specific capacity (∼ 540–600 mA h g–1) cyclability (0.0375% loss per cycle).

The Li–air battery has recently emerged as a potentially transformational energy storage technology for both transportation and stationary applications because of its very high specific energy; however, practical application is currently limited by the poor power capability (low current density), cyclability, low efficiency. All these are largely determined interfacial reactions on oxygen electrocatalysts in air electrode. In this article, we review fundamental understanding electrocatalysis...

In this work we demonstrated that uniform polycrystalline SnO2 nanotubes, in either array or free-standing form, can be fabricated by an infiltration technique using nanoparticles as starting building units. With method, the diameter, length, thickness, and texture of nanotubes further controlled. The tubular shows a significant improvement electrochemical performance over unorganized nanoparticles. specific capacity Sn-based nanotube electrode was 525 mAh/g after 80 cycles. principle,...

Abstract The development of a feasible and inexpensive strategy to obtain utilize sustainable energy is an important issue for the human society. Over past decade, significant progress has been made in novel functional materials conversion storage. Owing their unique physico‐chemical properties, 2D layered materials, such as graphene transition metal dichalcogenides, have attracted great interest energy‐related research. 1T‐MoS 2 metallic phase molybdenum disulfide (MoS ) with extraordinary...

A few types of crystalline hollow structures, carbon spheres (750 nm), with encapsulated or decorated 1−3 nm SnO2 nanoparticles, and (200−300 nm) synthesized by various methods, have been evaluated for reversible Li+ storage. The experimental results showed noticeable improvements in a number performance areas such as specific capacity, rate capability, cyclability. could be attributed to high degree crystallinity, which increases the electronic conductivity, facile transport Li ions shell...

This paper reports a hydrothermal preparation of NiO–graphene sheet-on-sheet and nanoparticle-on-sheet nanostructures. The nanocomposite showed highly reversible large capacities at common current 0.1 C good rate capabilities. A initial charge capacity 1056 mAh/g was observed for the composite C, which decreased by only 2.4% to 1031 after 40 cycles discharge charge. cycling performance is better than that NiO nanosheets, graphene NiO-graphene nanoparticle-on-sheet, previous carbon/carbon...

A unique CuO@NiO microsphere with three-layer ball-in-ball hollow morphology is successfully synthesized by Cu–Ni bimetallic organic frameworks. The beforehand facile microwave-assisted production of the Ni framework sphere used as template to induce control oxides. Designed controlled surface cationic exchange reactions between Cu and ions, there an elemental gradient (decreased amount CuO but increased NiO) from shell core product. This ternary metal oxide structure found be very suitable...

Abstract Rechargeable lithium batteries have attracted great attention as next generation power systems for electric vehicles (EVs). Lithium ion batteries, lithium–sulfur and lithium–oxygen are all suitable to be the EVs, but their densities cycling performance still need improved match requirements of practical EVs. Thus, rational design controllable synthesis electrode materials with unique microstructure outstanding electrochemical crucially desired. Porous carbon‐based composites many...

The metal–organic-framework (MOF) approach is demonstrated as an effective strategy for the morphology evolution control of MIL-53(Fe) with assistance microwave irradiation. Owing to homogeneous nucleation offered by irradiation and confined porosity skeleton MOF templates, various porous Fe2O3 nanostructures including spindle, concave octahedron, solid yolk–shell nanorod are derived simply adjusting time. formation mechanism precursors their iron oxides investigated. main product mesoporous...

Covalent organic frameworks (COFs) with reversible redox behaviors are potential electrode materials for lithium-ion batteries (LIBs). However, the sluggish lithium diffusion kinetics, poor electronic conductivity, low capacities, and rate performance most reported COF limit their further application. Herein, a new 2D (TFPB-COF) six unsaturated benzene rings per repeating unit ordered mesoporous pores (≈2.1 nm) is designed. A chemical stripping strategy developed to obtain exfoliated...

Abstract A novel metal–organic‐framework‐engaged strategy is demonstrated for the preparation of multishelled Co 3 O 4 @Co V 2 8 hybrid nanoboxes. This relies on unique reaction zeolitic imidazolate framework‐67 with vanadium source oxytriisopropoxide. Benefitting from synthetic versatility, a series nanostructures can be realized including triple‐shelled and double‐shelled nanoboxes single‐shelled When evaluated as electrode materials lithium‐ion batteries, these hollow structures...

Abstract Nonprecious metal single‐atom materials have attracted extensive attention in the field of electrocatalysis due to their low cost, high reactivity, selectivity, and atomic utilization. However, surface energy a single atom causes agglomeration during preparation catalytic measurement, resulting damage sites. The strong interaction between substrate monoatoms is key factor prevent aggregation individual atoms, geometry electronic structure catalysts can be adjusted optimize activity....

This paper reports the microwave-assisted synthesis of a Co3O4–graphene sheet-on-sheet nanostructure. nanocomposite showed an excellent high rate capability and highly reversible large capacity at common rate. A 931 mA h g−1 was observed current 5C (4450 g−1), which still larger than theoretical Co3O4 (890 mAh g−1). The substantially improved electrochemical properties were ascribed to unique nanosheets tightly stacked with graphene (GNS), therefore volume changes materials accommodated in...

Organic electrodes for low-cost potassium ion batteries (PIBs) are attracting more interest by virtue of their molecular diversity, environmental friendliness, and operation safety. But the sluggish diffusion kinetics, dissolution in organic electrolyte, poor electronic conductivity, low reversible capacities several drawbacks compared with inorganic counterparts. Herein, boronic ester based covalent framework (COF) material is successfully prepared on exterior surface carbon nanotubes...

Abstract Efficient and stable nonprecious metal electrocatalysts for oxygen reduction are of great significance in some important electrochemical energy storage conversion systems. As a unique class porous hybrid materials, metal–organic frameworks (MOFs) their composites recently considered as promising precursors to derive advanced functional materials with controlled structures compositions. Here, an “MOF‐in‐MOF hybrid” confined pyrolysis strategy is developed the synthesis Fe–Co...

Development of materials with carefully crafted nanostructures has been an important strategy for the next-generation lithium-ion batteries to achieve higher capacity, longer cycle life, and better rate capability. Graphene-based Sn-based anode are promising anodes capacities than graphite; however, most them exhibit fast capacity fading at prolonged cycling poor This paper reports a hierarchical Sn@CNT nanostructure rooted in graphene, which exhibits larger theoretical reversible 1160–982...

Graphene-wrapped CoS nanoparticles are synthesized by a solvothermal approach. The product is significantly different from porous microspheres prepared in the absence of graphene under similar preparation conditions. and CoS/graphene composite fabricated as anode materials for lithium-ion batteries. found to be better suitable an terms higher capacity cycling performances. nanocomposite exhibits unprecedented high reversible 1056 mA h/g among all cobalt sulfide-based materials. Good...