Mesoporous nano-microparticles lithium-rich Zn-doped Li1.2Mn0.54Co0.13Ni0.13O2 cathode materials have been synthesized by utilizing the structural characteristics of metal–organic frameworks. The electrochemical performance is improved by the substitution of an appropriate amount of Zn into the layered Li-rich Li1.2Mn0.54Ni0.13Co0.13O2 cathode material.

Hierarchical porous ZnMn2O4 microspheres assembled by nanosheets with an average thickness of several nanometers are successfully synthesized by a facile hydrothermal method and subsequent calcination at 500 °C in air. When used as an anode electrode of lithium ion batteries (LIBs), the ZnMn2O4 microspheres exhibit a high discharge capacity of 1132 mA h g−1 after 500 cycles at a current density of 500 mA g−1 and excellent rate capability. It is believed that the outstanding electrochemical performance benefits from the hierarchical porous structure that can not only increase the contact area between the electrode and the electrolyte to facilitate the transfer of Li+ ions, but also provide sufficient space for volume expansion of the electrode during the cycling process.

•A peapod-inspired MnO@C core-shell anode has been successfully fabricated.•The peapod structure possesses stable interface and high structural reversibility.•The MnO@C exhibits superior electrochemical properties for Li ion storages.Inspired by the structure of peapod, MnO@C hybrid with internal void space has been prepared. In this bionic structure, the MnO nanoparticles are separated and confined in a conductive carbon sheath that leaves enough room for expansion and contraction during lithiation/delithiation process. Such peapod-like MnO@C can address the issues related to MnO dissolution, pulverization, and aggregation. As a result, the sample demonstrates superior electrochemical performances in terms of high reversible capacity, excellent high-rate capability, and good cyclability.Inspired by the structure of a peapod, MnO@C hybrid with internal void space has been prepared. In this bionic structure, the MnO nanoparticles are separated and confined in a conductive carbon sheath that leaves enough room for expansion and contraction following lithiation/delithiation process. The resulting peapod-like MnO@C demonstrates superior electrochemical performances in terms of high reversible capacity, excellent high-rate capability, and good cyclability.

•Facile protocol for microstructure tailoring of Cu-cored nanowire array is described.•The electrode shows high areal capacity, superior rate capability and ultralong cycling life.•Surface roughening of Cu nanowire enhances the interfacial adhesion between Cu and Sn.•Microstructure refinement makes the Cu@Sn electrode competitive for micro-energy storage.The impact of morphological and compositional evolutions of arrayed Cu@Sn nanoelectrodes on their lithium storage capability is investigated in this work. Strikingly, it is found that the diameter of Cu nanowire-core, inter-wire spacing, as well as Sn/Cu ratio of such nanohybrids could be directly adjusted through a synchronous electrochemical dissolution/deposition strategy in a single bath. In line with expectation, nanoarchitecture tailoring of the array-type electrode brings in expanded space available and enhanced interfacial adhesion, which can not only effectively enable high loading of conformal Sn nanolayers on per unit footprint area but also help in suppressing capacity fading, and thus harvesting outstanding areal capacity (∼1.46 mAh cm−2 at 0.2 mA cm−2) and rate capability. It is envisioned that such work will shed light on ways to facilely tune the characteristic parameters of a series of Cu-cored hybrid nanowire arrays with desired functionalities for nanodevice applications.

•A novel structure that ZnO nanoparticles encapsulated in a 3D hierarchical carbon framework (ZnO@CF) has been fabricated.•The ZnO@CF is prepared through a simple hydrothermal method and subsequent post-processes.•The ZnO@CF exhibits very high initial discharge capacity.•The ZnO@CF exhibits excellent cycling stability and good rate capability.A novel structure that ZnO nanoparticles encapsulated in a 3D hierarchical carbon framework (ZnO@CF) has been fabricated through hydrothermal method and subsequent post-processes. In this structure, the surface carbon coating layer combines with the inside carbon to form a stable 3D carbon framework that encapsulated and anchored the ZnO nanoparticles. The developed ZnO@CF structure can not only improve electronic conductivity, but also alleviates the structural strain associated with repeating Li+ insertion/extraction processes so as to maintain structural stability. When used as anode for lithium ion battery, the ZnO@CF electrode exhibits a high reversible capacity of 850 mAh g−1 at a current density of 0.1 A g−1 after 200 cycles. Moreover, it shows good rate capability even when cycled at 2 A g−1.

Arrays of self-supported core–shell nanowire have attracted considerable attention with respect to improved capability for electrochemical energy storage. Herein, we report a facile strategy, involving hydrothermal and liquid phase deposition (LPD) routes, to fabricate nano-coaxial Co3O4/TiO2 arrays with intriguing morphologies, architectures, and chemical compositions. When tested as anode materials for lithium ion batteries, these nanohybrids exhibited high reversible capacity, excellent cycling stability and good rate capability. It is assumed that the excellent electrochemical performance originates from the intricate core–shell nanoarchitecture and the coating effect of TiO2, including improved mechanical/chemical stability and good strain accommodation. The improved lithium ion storage performance of the Co3O4/TiO2 nanostructure indicates its potential application as an anode material for electrochemical energy storage and the potential use of TiO2 coating for modification of other anode materials.

Lithium-rich layered Li1.2Ni0.13Co0.13Mn0.54O2 cathode materials have been successfully fabricated by a glucose-assisted combustion method combined with a calcination treatment. The effect of the amount of glucose fuel on the properties of the prepared materials is investigated by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and electrochemical measurements. The results show that the nano-sized cathode material obtained at a fuel ratio of φ = 1 exhibits uniform fine well-crystallized particles with the largest specific surface area, leading to excellent cyclic capability and rate performance. It delivers the highest initial discharge capacity of 280.5 mA h g−1 with a capacity retention of 84% after 50 cycles at 0.1C (25 mA g−1). Besides, after cycling at an increasing rate from 0.2C to 3C, the electrode retained 90.3% (230.2 mA h g−1) of the initial discharge capacity when the rate was recovered back to 0.2C.

The future development of large-scale energy store systems requires Li-ion batteries (LIBs) with not only an outstanding electrochemical performance but also sustainability and cost-effectiveness. Herein, unique carbon-sheets (CSs) with rich porosity and high graphitization have been synthesized from sugarcane-stalk for LIBs application. These derived CSs exhibit a superior electrochemical behavior to commercial graphite. Moreover, the performance of CSs can be further upgraded by growing MnO nanoparticles to form a synergetic MnO–C hybrid. As a result, the MnO–C hybrid shows a high capacity, excellent rate capability (354 mA h g−1 at 3 A g−1), and superior cycling performance (814 mA h g−1 at 0.2 A g−1 after 400 cycles).

A 3D defect controllable graphene foam (GF) with a conductive interconnected network is prepared by a CVD process in a closed environment, which we refer to as the closed-environment CVD method. The resulting GF is not only high quality, but is also provided with controllable defect density, offering a great potential in Lithium-ion battery (LIB) applications. When ZnO is anchored on the 3D GF to construct a ZnO/GF composite as the anode for LIBs, benefiting from the advantages of graphene and unique structural features, it exhibits a high reversible capacity of 851.5 mA h g−1 at 0.2 A g−1, good cycling performance and excellent rate capability. Notably, the higher defect density of GF leads to an increase in the capacity of ZnO/GF, meanwhile, it maintains an excellent rate performance.

A binder-free method is applied to avoid the huge irreversible capacity of Sn-based composite anodes in this paper. We report two types of copper-based current collector: (i) a light and flexible current collector, which is fabricated from copper nanowires (CuNWs), and (ii) Cu foam with copper nanowires grown on it. The charge capacity of the thin CuNW sheet based Sn–Cu composite anode remains above 760 mA h g−1 after 60 cycles with a relatively stable coulombic efficiency fluctuating around 97%. The Cu foam based composite anode also shows a good capacity retention of 79.8% after the same test, compared with the Cu foil based anode. According to the good rate performance and the light weight of the composite electrode, the CuNW sheet based current collector may be a promising material in energy fields in the future.

A 3D carbon framework has been introduced into a MnO yolk–shell structure, which functions as an electrical highway and a mechanical framework that improves the reaction kinetics, prevents MnO from fracturing and agglomerating, and limits most SEI formation to the carbon surface instead of on the MnO–electrolyte interface. As a result of this arrangement, the sample demonstrates a maximum reversible specific capacity of 1040 mA h g−1 at rate of 0.2 A g−1 with a long cycle life (without any decrease after 500 cycles), and an outstanding charge/discharge rate capability (513 mA h g−1 at 4 A g−1).

A porous carbon nanofibers/nanosheets hybrid (CNFS) is converted from cornstalk waste by a simple treatment. The resulting material displays a superhigh surface area and rich porosity. Benefiting from unique structural features, the evolved CNFS possesses an ultrahigh rate capability of 454 mA h g−1 at 3 A g−1.

In this study, a scalable one-pot template-free synthesis strategy was employed to fabricate CuO-incorporated TiO2 hollow microspheres in large scale. The as-prepared hollow spherical TiO2 nanoparticles possess unique structural characteristics, namely, large surface area and a hierarchical nanoarchitecture composed of a hollow macroporous core connected with large mesopores in the shell. The large surface area provides a great number of surface active sites for the reactant adsorption and reaction whereas the hierarchical nanoarchitecture enables fast mass transport of reactant and product molecules within the porous framework. In addition, the hollow macroporous core–mesoporous shell nanostructure favors multilight scattering/reflection, resulting in enhanced harvesting of exciting light. Furthermore, the incorporated CuO clusters work efficiently as a cocatalyst to improve the photocatalytic activity. As a result, the CuO-incorporated TiO2 hollow microsphere catalyst demonstrates much higher photocatalytic activity toward photodriven reduction of CO2 with H2O into CH4 compared with the state-of-the-art photocatalyst, commercial Degussa P25 TiO2. Also, the simple synthesis strategy would enable large-scale industrial production of CuO–TiO2 hollow microspheres.Keywords: CuO; Hierarchical nanoarchitecture; Hollow microspheres; Photocatalytic CO2 reduction; Titania;

A metal network fabricated by copper nanowires (CuNWs), synthesized in a facile way, is introduced to silicon composite anode as current collector for lithium-ion battery. The light and flexible sheet can act as the collector and the substrate, and improve the kinetic electron transport and the stability of composite anode. In this configuration, the composite anode exhibits a better capacity retention of 89.4% and a coulombic efficiency of ∼93% after 60 cycles (rate = 0.2C) compared to conventional composite thin film anode in which CuNWs are beneficial for electrochemical performances. There appears to be a promising improvement that the light-weighted anode can also be applied to meet the commercial requirement.

N-doped hollow hierarchical peanut-like carbon-shells with nanorod arrays on the surface and interconnected networks in the core are prepared, which display rich porosity, superhigh specific surface area and a high degree of graphitization. The unique composition and hierarchical structure of the carbon resulted in very promising electrochemical energy storage performance.

Lithium-rich Li1.2Mn0.6Ni0.2O2 microspheres with a few mesopores have been successfully obtained. The results show that the Li1.2Mn0.6Ni0.2O2 material exhibits excellent cycling capability and rate performance. The microsphere morphology with a few mesopores could play a significant role in improving electrochemical performance.

Peanut-like MnO@C core–shell composites with an internal carbon network (P-MnO@C) were prepared via an in situ synchronous graphitization and reduction process. These P-MnO@C composites exhibit high specific capacity and rate capability, good stability and excellent long-term cycling life for application in lithium ion batteries.

Interdispersed MnO nanoparticles that are anchored and encapsulated in a three-dimensional (3D) porous carbon framework (MnO@CF) have been constructed, which display nanosphere architecture with rich porosity, well-defined carbon framework configuration, and excellent structure stability. When evaluated as an anode material, the MnO@CF exhibits relatively high specific capacity of 939 mA h g–1 at current rate of 0.2 A g–1 over 200 cycles and excellent rate capability of 560.2 mA h g–1 at 4 A g–1. By virtue of its mechanical stability and desirable ionic/electronic conductivity, the specific design can be a promising approach to fabricate high-performance lithium-ion batteries.Keywords: carbon framework; interconnected carbon network; lithium-ion batteries; MnO; porous structure

In this study, a simple and reproducible synthesis strategy was developed to fabricate mesoporous carbon nanofibers (MCNFs) by using dual hard templates, a porous anodic aluminum oxide (AAO) membrane, and colloidal silica (Ludox TM-40). By using commercial templates, and removing AAO and the silica simultaneously, the synthesis procedures for MCNFs are greatly simplified without the need for separate preparation or the removal of templates in sequence. With phenol resin as a carbon precursor, the as-prepared MCNFs material reveals not only high surface area and mesoporous volume but also hierarchical nanostructure composed of hollow macrochannels derived from the AAO template, large mesopores (ca. 22 nm) from the removal of silica particles and micropores from the carbonization of phenol resin. Such unique surface and structural characteristics could provide a large quantity of active sites for Li storage and facilitate fast mass transport. Moreover, a one-dimensional (1D) carbon nanofiber (CNF) nanostructure favors fast electron transfer. The as-prepared MCNF anode demonstrates ultrahigh lithium storage capacity particularly at high rates, which is much higher than that reported for the commercial graphite and also significantly higher than other nanostructured carbon materials, such as ordered mesoporous carbon CMK-3 and ordered multimodal porous carbon (OMPC).Keywords: hierarchical porosity; lithium storage; mesoporous carbon nanofibers; nanostructured carbon; template method;

•Hollow carbonized polypyrrole spheres are prepared by a template method.•Sulfur is distributed uniformly on the shells of carbonized polypyrrole spheres.•The carbonized polypyrrole/sulfur composite shows good electrochemical properties.•The remaining capacity is 758 mA h g−1 after 400 cycles at 0.2C rate.Hollow carbonized polypyrrole (PPy) spheres are synthesized using poly(methyl methacrylate–ethyl acrylate–acrylic acid) latex spheres as sacrificial templates. The hollow spherical carbonized PPy/sulfur composite cathode materials are prepared by heating the mixture of hollow carbonized PPy spheres and element sulfur at 155 °C for 24 h. Scanning electron microscope (SEM) and transmission electron microscope (TEM) observations show the hollow structures of the carbonized PPy spheres and the homogeneous distribution of sulfur on the carbonized PPy shells. The hollow spherical carbonized PPy/sulfur composite with 60.9 wt.% S shows high specific capacity and excellent cycling stability when used as the cathode materials in lithium/sulfur cells, whose initial specific discharge capacity reaches as high as 1320 mA h g−1 and the reversible discharge capacity retains 758 mA h g−1 after 400 cycles at 0.2C. The excellent electrochemical properties benefit from the hollow structures and the flexible shells of the carbonized PPy spheres.

•Arrayed SnS@Cu core–shell nanowires were engineered for Li+ storage application.•The reversible capacity is 347 mAh g−1 (3.3C) even after 80 rate-varying cycles.•Innovative electrochemical fabrication of SnS/CuS nanotubes array was achieved.•Designed 3D architecture can boost application of metal sulfides in smart energy storage.Three-dimensional (3D) nanoarchitectures have demonstrated substantial advantages in capturing the performance of traditional electrode materials. In this regard, novel Cu@SnS core–shell nanowire array is fabricated via a rational electrochemical assembly strategy. Meanwhile it is also discovered that striking structural and compositional evolution from Cu@SnS core–shell nanowires to hybrid CuS/SnS nanotubes can be achieved by a simple tuning of reaction conditions. As a proof of concept, long-term cycling stability and remarkable rate capability are exhibited by Cu@SnS nanoelectrode in the study of its Li+ storage properties (e.g., it delivers a capacity of ∼347 mAh g−1 at 3.33C even after 80 rate-varying cycles), which verifies the effectiveness of the designed 3D configuration in tackling possible electrical/mechanical failures of the electrode during repeated Li+ uptake/release process. Moreover, because of their potential for achieving high power and energy densities on a small footprint area, the designed metal sulfide nanoelectrodes may be promisingly applied in microenergy storage devices.

•Uniform PI membranes are fabricated by electrospinning.•PI-GEL electrolyte is synthesized by incorporating TEGDA-BA copolymer.•It shows high ionic conductivities and electrochemical stabilities.•The mechanical properties of PI-GEL are highly improved.•The cells using PI-GEL demonstrate stable charge/discharge performance.Robust electrospun polyimide (PI) membranes are simply fabricated by polymerization of oxidianiline (ODA) and pyromellitic dianhydride (PMDA). The as-prepared PI membranes, with reliable safety (self-extinguishing) and excellent mechanical property, exhibit highly uniform morphology with an average fiber diameter ∼ 600 nm, high porosity ∼67%, high electrolyte uptake ∼534% and good relative absorption ratio ∼75% of the initial absorption (electrolyte uptake until 240 min). With the presence of triethylene glycol diacetate-2-propenoic acid butyl ester (TEGDA-BA) gel electrolytes, the resulting polyimide-gel electrolytes (PI-GEL) show a high ionic conductivity up to 2.0 × 10−3 S cm−1 at 25 °C, coupled with high electrochemical stability (>4.5 V vs. Li/Li+). The Li/PI-GEL/LiFeO4 cells demonstrate remarkably stable charge/discharge performance and excellent capacity retention of ∼146.8 mAh g−1 (0.1 C) after 100 cycles. The results suggest a facile strategy for scalable fabrication of high-performance polymer electrolyte membrane for lithium ion batteries.

Ni/Ni(OH)2@multiwalled carbon nanotube (MWCNT) coaxial nanocable (NMCNC) film was fabricated by an easy and low cost one-step electrophoretic deposition approach. The formation mechanism was discussed in details. For comparison, MWCNT film and Ni/Ni(OH)2 film were also fabricated. Compared with its counterpart Ni/Ni(OH)2 film, the NMCNC film exhibited more homogeneous and nanoporous morphology, much larger surface area and thus better capacitive performance. The NMCNC film showed a high specific capacitance of 1642 F g−1 at a high current density of 5 A g−1. As the current was increased to 100 A g−1, the NMCNC film could retain a relatively high capacitance of 895 F g−1. After 1000 charge/discharge cycles at 5 A g−1, the NMCNC film showed a capacitance retention rate of 81%. The excellent capacitive performance can be attributed to the structure advantages of the NMCNC film.

•Simple co-templates synthesis strategy for fabricating mesoporous carbon nanofibers.•Unique hierarchical porosity of macro-, meso-, and micropores and high surface area.•Stores and delivers large amount of hydrogen rapidly whether at a low or high rates.•Considerably outperforms ordered mesoporous carbon for hydrogen storage.A colloidal silica incorporated porous anodic aluminum oxide (AAO) was utilized as a dual-template to prepare mesoporous carbon nanofibers (MCNFs). Such a strategy is simple because it takes advantage of commercially available materials (i.e., colloidal silica and AAO) and the templates can be removed in one step. The as-prepared MCNF shows a hierarchical nanostructure consisting of open macroporous channel connected with large mesopores and micropores. As a result of the large surface area and unique hierarchical nanoarchitecture which facilitates fast mass and electron transport, the MCNF reveals a discharge capacity of 679 mA h g−1 at 25 mA g−1. This value is significantly greater than that (i.e., 394 mA h g−1) observed for an ordered mesoporous carbon (OMC) with a similar specific surface area. Furthermore, at 3000 mA g−1, the MCNF demonstrates a discharge capacity of 585 mA h g−1, which is about twice that (i.e., 256 mA h g−1) of the OMC.

•A narrow size distribution and uniformly dispersed Pd nano-particles were obtained.•A high catalytic property PdSnO2/CNTs were synthesized using polyol reduction method.•The catalytic activity of PdSnO2/CNTs for methanol oxidation is up to 778.8 mA/mg Pd.•Methanol oxidation on PdSnO2/CNTs has an exchange current density of 3.76 × 10−4 A cm−2.The methanol electro-oxidation (MEO) on Pd–SnO2/MWCNTs catalysts prepared by microwave-assisted polyol reduction method has been investigated. The structure, morphology and electro-catalytic performances of the catalysts were characterized with XRD, TEM and cyclic voltammetry (CV). The results showed that the highly dispersed Pd nano-particles (PdNPs) with a narrow size distribution on MWCNTs were successfully synthesized. The catalytic activity of Pd–SnO2/MWCNTs for MEO was up to 778.8 mA/mg Pd in 0.1 M KOH solution containing 1 M methanol, which was significant higher than that of Pd/C (414.2 mA/mg Pd) or Pd–SnO2/C (566.7 mA/mg Pd). Moreover, the MEO on Pd–SnO2/MWCNTs electrode displayed an irreversible behavior under a diffusion control giving an exchange current density (j0) of 3.76 × 10−4 A cm−2 and a Tafel slope of 149 mV dec−1 (α = 0.56) at 25 °C, which indicates that Pd–SnO2/MWCNTs catalyst has a high electro-catalytic performance for the MEO in alkaline media.

Three-dimensional (3D) electrodes of Cu@Fe3O4 nanowire arrays for Li-ion batteries are prepared by an electrochemical route. XRD, SEM, TEM and HRTEM are used to characterize the micromorphology. The structures are improved, which is beneficial for the electrochemical performances. The obtained electrodes show a higher initial capacity than the traditional Cu@Fe3O4 planar electrodes. Moreover, the 3D electrodes exhibit better long-term cycling stability and an appealing rate capability.

Multiwalled carbon nanotube (MWCNT)/α-MnOOH coaxial nanocable (MMCNC) films are successfully fabricated by a simple and low-cost electrophoretic deposition (EPD) process. The as-prepared MMCNC films exhibit three-dimensional (3D) nanoporous network structure. A possible mechanism is proposed to explain the formation of the MMCNC films. Electrochemical test results show that the films exhibit superior capacitive behaviors and cycle stability in 0.1 M Na2SO4 aqueous solution. The thickness, mass loading and capacitive performance of the MMCNC films can be easily and continuously tuned by varying the deposition time. A relatively high mass specific capacitance of 327 F g−1 is obtained from the films with relatively low mass loading of 0.05 mg cm−2, while, a relatively high areal capacitance of 0.2 F cm−2 is achieved when the mass loading was increased to 1.38 mg cm−2. The superior capacitive performances can be attributed to the unique structure advantages of the MMCNC films. On one hand, the one-dimensional (1D) coaxial nanocable structure works, with MWCNT core serving as high electronic conductive frame and α-MnOOH sheath providing high pseudocapacitance. On the other hand, the 3D nanoporous network structure can facilitate fast ions transportation.Graphical abstractHighlights► Electrophoretic deposition of Multiwalled carbon nanotube/α-MnOOH coaxial nanocable films. ► 3D nanoporous network structure can facilitate fast ions and electron transportation. ► The films exhibit superior capacitive behaviors and cycle stability. ► Energy storage mechanism of MnOOH as supercapacitor electrode material is discussed. ► Their capacitive performances can be tuned by varying the deposition time.

•The concentration of acetic acid solution strongly affects the dealloying process.•The concentration of acetic acid solution has a key effect on microstructure of NPC.•The nanopore formation rate rises firstly and then falls with solution concentration.•The change is caused by competitive effect between association and ionization.•The concentration of H+ in acetic acid solution is evaluated by calculation.The dealloying behavior of single-phase Mn–30Cu sheets in acetic acid solutions with varying concentrations ranging from 1 vol.% to 60 vol.% and morphological evolution of nanoporosity have been investigated. The results show that the concentration of acetic acid solution has a key influence on the dealloying process and microstructure of nanoporous copper. It can be well explained as a consequence of the competition between association and ionization of acetic acid molecules. Additionally, the formation rate of porous structure in organic acid solution is remarkably lower than that in inorganic acid due to the limited H+ concentration from the competitive effect.

•One step electrophoretic deposition of hierarchical Co3O4@MWCNT nanocable films.•The weight content and morphology of the Co3O4 sheath can be conveniently tuned.•A micro-cathode induced coating mechanism can explain the formation of the nanocables.•The hierarchical architecture leads to superior cyclability and high capacity.•High capacity of 860 mAh g−1 is achieved at 1 C and no decay is found after 250 cycles.Hierarchical Co3O4@multiwalled carbon nanotube (MWCNT) nanocable films are deposited on copper foils via a facile one-step electrophoretic deposition (EPD) from MWCNT suspension containing Co(NO3)2·6H2O and the subsequent heat treatment. The obtained films show network morphologies, with micro-/mesoporous Co3O4 sheath uniformly coated on the interconnected MWCNT core. By varying the mass ratios of Co(NO3)2·6H2O to MWCNTs in the suspension, a series of nanocable films are obtained with different Co3O4 sheath thickness, morphology, and mass content. Among them, the Co3O4@MWCNT-4 nanocable film, with a high surface area of 156 m2 g−1 and optimally hierarchical pore size distribution, proves to be a qualified candidate anode for lithium-ion batteries. The reversible capacity can reach as high as 1109 mAh g−1 at a relatively high current of 0.2 C (1 C = 890 mA g−1). At a higher current of 1 C, the reversible capacity can retain as high as 860 mAh g−1 and shows no obvious decay after 250 cycles.

Au nanoparticles (AuNPs) supported on activated carbon (Au/C) were prepared by a modified chemical reduction method. The morphology, structure, surface chemical state and electro-oxidation activity of AuNPs were investigated by the transmission electron microscope (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV) and chronoamperometry. Results indicated that the Au/C catalyst possessed small AuNPs with a certain number of gold oxide species. This intrinsic property resulted in the high catalytic activity of the Au/C catalyst for the electro-oxidation of alcohol molecule. The peak values of anodic mass-specific current densities on AuNPs reached 69.5, 442 and 660 mA mg−1Au, respectively in 0.1 M KOH solutions with 6 M methanol, 2 M ethanol and 0.5 M ethylene glycol.Highlights► A series of Au/C catalysts are synthesized by a deposition-reduction process. ► Alkalescent medium is suitable for preparing the Au/C catalyst with high Au loading. ► Excessive KBH4 can employ as a sedimentation promoter for colloid AuNPs. ► Au/C catalyst shows good activity and poison tolerance for the ethanol oxidation.

•SEM and TEM images present a uniformly distributed nanosize of 20–200 nm.•The results indicate that this material possesses high discharge capacity and quite good cycling stability.•The initial discharge specific capacity is 251.9 mAh g−1 at 1 C (250 mA g−1).•It delivers 107.5 mAh g−1 for the first cycle and remains 82.7 mAh g−1 after 500 cycles at 10 C.High-capacity Li[Li0.2Mn0.54Ni0.13Co0.13]O2 has been successfully synthesized as a cathode material for Li-ion battery by hydrothermal method. The prepared materials are characterized by XRD, SEM, TEM, EDS, XPS and electrochemical measurements. The XRD result shows that Li[Li0.2Mn0.54Ni0.13Co0.13]O2 material formed a pure phase. SEM and TEM images present a uniformly distributed nanosize of 20–200 nm. The results of CV, charge–discharge tests indicate that this material possesses high discharge capacity and quite good cycling stability. It delivers 251.9 mAh g−1 and 107.5 mAh g−1 for the first cycle and remains 139.4 mAh g−1 and 82.7 mAh g−1 after 500 cycles, respectively, corresponding to 1 C and 10 C.

•AuNi/C catalyst is synthesized by the impregnation method in the glycol system.•The AuNi system phase-separations are detected in the nano scale.•The Ni content in catalyst first goes up and then down with the annealing temperature.•AuNi/C catalyst has a better activity than Au/C catalyst for the methanol oxidation.AuNi nanoparticles supported on the activated carbon (AuNi/C) are synthesized by the impregnation method in the ethyleneglycol system using NH2NH2·H2O as a reducing agent. The alloying of Au and Ni and the removal of unalloyed Ni in the AuNi/C composition are achieved by heat and acid treatments in sequence. Research results reveal that the average size and alloying degree of the AuNi nanoparticles in the AuNi/C catalyst increase with the enhancement of the annealing temperature. However, the Ni content of the AuNi/C catalyst firstly goes up and then down with the rising of heat treatment temperature due to the AuNi system phase-separates. Moreover, the electrocatalytic activity normalized by the electrochemically active surface area of each AuNi/C catalyst is far better than that of the Au/C catalyst, because of the bifunctional mechanism and the electrocatalytic activity of the NiOOH. In particular, the AuNi/C catalyst annealed at 400 °C exhibits the most excellent activity, due to its small AuNi particles and proper alloying degree. Furthermore, its mass-specific electrochemical activity is higher than that of the Au/C catalyst, although the mean diameter of the AuNi nanoparticles in this catalyst is larger than that of the Au nanoparticles.

Silicon is the most promising anode material to replace graphite in lithium ion batteries due to its high theoretical capacity of 4200 mAh g−1. However, the enormous volume expansion of bulk Si during the lithiation process results in severe electrode degradation and capacity decay. Extensive research effort has been devoted to fabricating nanostructured Si-based materials to improve the capacity cycling stability. Herein, a facile two-step approach is developed for the fabrication of novel three-dimensional (3D) nanoarchitectures composed of polypyrrole–silicon (PPy–Si) core–shell nanofibers. Electropolymerized PPy nanofibers are utilized as the flexible substrate for the deposition of Si thin films via a chemical vapor deposition (CVD) procedure. In this well-designed configuration, the PPy nanofibers are favorable for facile charge delivery and gathering, while the porosity of the electrode can efficiently cushion the volume expansion of Si. The electrode delivers a high reversible capacity above 2800 mAh g−1 with appealing cycling stability (∼91% capacity retained after 100 cycles). The rate capability of the electrode is also remarkable with a high capacity and stability. It is revealed that the reticular nanofibers’ morphology is well preserved after repeated lithium insertion and extraction, which certainly indicates the superiority of our electrode design. This fabrication approach can also be extended to other electrodes for electrochemical energy conversion and storage.

One of the major challenges in creating devices with core–shell nanotubular heterostructures has been the coating of conformal nanolayers inside the open volume of a nanoporous template. Here we show two facile assembly strategies developed, utilizing either electrochemical or solvothermal methodology, for the successful synthesis of novel SnO2@TiO2 coaxial nanotube arrays (SnO2@TNTs). Remarkably enhanced Li+ ion storage performance of the prepared nanohybrids with favorable and well-defined tubular structures is demonstrated to be derived from the synergistic effect with improved electronic conductivity and dual lithium storage mechanism, which highlights their potential as a new alternative material for electrochemical energy storage.

SnO2 nanoparticles uniformly decorated polypyrrole (PPy) nanowires are synthesized by a facile two-step electrochemical reaction method: electropolymerization and electrodeposition. The nanostructured SnO2–PPy hybrids show porous reticular morphology and homogenous distributions. The reticular SnO2–PPy nanowires can increase the electrode/electrolyte interface and accommodate the volume variation of SnO2. When applied as anode materials for lithium ion batteries, the unique nanostructured hybrids deliver meaningfully improved Li+ storage performance with the first reversible capacity of 690 mAh g−1. This facile synthesis procedure can also be simply grafted to other inorganic–organic hybrid composites.Highlights► SnO2 nanoparticles coated polypyrrole nanowires are introduced into Li-ion battery. ► The polypyrrole networks serve as structural support and allow electrolyte immersion. ► The nanostructured composites deliver high capacity and long cycle life.

We develop a general dealloying strategy to sequentially synthesize nanoporous intermetallics, nanoporous metals with bimodal, and unimodal pore size distributions. Typically, this strategy here was employed to fabricate nanoporous copper-based intermetallics (NPCBI), nanoporous copper (NPC) ribbons with bimodal, and unimodal pore size distributions by chemical dealloying of dual-phase Cu–M (M: Mg and Al) alloys with quasieutectic structures in an acidic solution. The results show that these porous products can be sequentially achieved by simply changing the dealloying times. Additionally, their morphological evolutions upon dealloying were investigated, and the formation mechanism is discussed.Graphical abstractHighlights► A general strategy to nanoporous intermetallics, nanoporous metals is developed. ► These products can be sequentially obtained by changing dealloying times. ► Typically, nanoporous copper-based intermetallics, nanoporous copper are fabricated. ► This approach possesses advantages of simple processing, nearly absolute yield. ► This work will have implications for further fabricating novel porous materials.

Aucore–Ptshell (Au@Pt) nanoparticles supported on activated carbon (Au@Pt/C) are synthesized by an epitaxial growth method using HCOONa as a reducing agent. Through the characterization of the transmission electron microscope (TEM), high resolution TEM (HRTEM), high angle annular dark-field scanning TEM (HAADF-STEM) and X-ray powder diffraction (XRD), the Pt atoms grow epitaxially on the surface of the Au nanoparticles to form Pt shells with Au fcc structure. According to the results of the X-ray photoelectron spectroscopy (XPS), electrons transfer from Pt to Au. Cyclic voltammetry is employed to investigate the catalytic activities of the Au@Pt/C catalysts for the methanol electrooxidation (MEO) and the CO stripping. The results of the electrochemical measurements indicate that, the Au fcc structure of the Pt shell and the decrease in the electronic effect are propitious to the increases in the catalytic activity for the MEO and the CO tolerance of the Au@Pt/C catalysts.Highlights► A series of Au@Pt/C catalysts are synthesized by an epitaxial growth method. ► The Pt binding energy increases due to the transfer of electrons from Pt to Au. ► The Pt shell with Au fcc structure reveals high electrocatalytic activity. ► The Pt shell with Au fcc structure has outstanding anti-CO adsorption ability. ► The Au@Pt/C catalysts exhibit high catalytic activity and excellent CO tolerance.

The exfoliation of Sn as a result of volume expansion led to the drastic capacity decay in lithium-ion batteries. In this article, the immiscible Sn–Zn coating was successfully prepared by electrodeposition and applied as the anode material in Li-ion batteries. The physical structure and electrochemical properties were characterized by X-ray diffraction, scanning electron microscope, electron probe microanalysis and charge–discharge test, respectively. The Sn–Zn deposit displayed unique two-layer morphology composed of a Zn flat bottom layer and a Sn dendritic upper layer. The novel Sn–Zn electrodes showed noticeable improvement in cyclability compared to pure Sn film. This improvement was assigned to the characteristic of the two-layer microstructure: the Zn interlayer enhanced the binding strength between Sn dendrites and copper foil; the abundant space among these individual Sn dendrites accommodated the volume expansion during lithiation process. The two-layer Sn–Zn coatings were anticipated as potential anode materials for Li-ion batteries.

The electrodeposited nickel nanocone-arrays without any template are introduced to Sn-based anode materials as current collector for lithium ion battery. Nickel nanocone-arrays are tightly wedged in the electrodeposited Sn film, and thereby enhance the interfacial strength between active materials and substrate. Furthermore, annealing is conducted to form Sn–Ni alloy, in which Ni renders an inactive matrix to buffer volume change during cyclic lithiation/delithiation. The nanocone-arrays supported Sn–Ni alloy anode shows satisfactory Li+ storage properties with the first reversible capacity of 807 mAh g−1. The charge capacity for the 50th cycle is 678 mAh g−1, delivering good retention rate of 99.6% per cycle. These improved performances of nickel nanocone-arrays supported Sn–Ni alloy anodes indicate the potential of their application as electrode materials for high performance energy storage.Highlights► Nickel nanocone-arrays supported Sn-based electrodes were investigated for the first time. ► The reversible capacity for the 70th cycle was 614 mAh g−1 with superior retention of 99.6% per cycle. ► The nanocone-arrays buffered the volume variation and enhanced the adhesion strength between the active materials and current collectors. ► This approach was general and facile to be exploited for other active materials to achieve a high-capacity and durable electrode.

Nanoporous copper (NPC), as a new kind of porous metal prepared by dealloying, is introduced into the lithium-ion battery as both the current collector and substrate of active material. The nanoporous copper has three-dimensional structure composed of large channels (hundreds of nanometers) and small pores (tens of nanometers) on the channel walls. Anodes were prepared by electroless depositing of a thin layer of tin on NPC and copper foil. By comparing the electrochemical performance of both electrodes, the nanostructured electrode exhibits much higher areal capacity and better Coulombic efficiency than planar electrode.

A novel cathode material, polysulfide polypyrrole was successfully designed and synthesized for high-energy lithium–sulfur secondary batteries. The product was characterized by FT-IR, element analysis and DSC. Character results show that the polymer was obtained with polypyrrole as backbone and S–S side groups attached to it. Polypyrrole backbone in this polymer was used not only as container but also as conductivity passage. Cycle performances of the polymer was examined as active cathode material in lithium batteries, charge–discharge experimental results indicate that the polymer has a specific capacity of 515 mAh g−1 at the first cycle and 452 mAh g−1 at the 20th cycle. The improved cycle properties compared to other polymer disulfides and polysulfide polymers supply a good foundation for practical application of this material in rechargeable lithium batteries.Highlights► Polysulfides polypyrrole (SPPy) is a conducting polymer with high capacity. ► The SPPy contains 2 active structure units which could insert lithium. ► The way to combine 2 or more active material together might be a good way out.

An alkaline medium has been used to fabricate monolithic nanoporous copper (NPC) ribbons through chemical dealloying of melt-spun Al–Cu alloys with 33–50 at.% Cu. The results show that phase constituent and proportion in the initial alloys have a key influence on the formation of NPC. The alloy ribbons comprising one or a combination of Al2Cu and AlCu can be fully dealloyed in alkali solution only when there is no or a minor AlCu in the initial alloys. Additionally, the length scales of ligaments/pores in NPC can be broadly modulated by simply changing the amount of AlCu in the initial alloys.Research highlights► An alkaline medium can be used to fabricate NPC by dealloying of multi-phase Al–Cu alloys. ► The alloys with no/a minor AlCu can be fully dealloyed, resulting in the formation of uniform NPC. ► The alloy with the amount of Al2Cu comparable to that of AlCu can be partially dealloyed, forming NPC/AlCu composites. ► The dealloying of the alloy comprising almost single AlCu just can be proceeded on the surfaces. ► The length scales of ligaments/pores in NPC can be modulated in a broad size range.

We present a facile and effective one-pot strategy to synthesize nanoporous copper (NPC) with controlled hierarchical pore size distributions which can be fabricated through chemical dealloying of the melt-spun Al-35Cu alloy in a 10 wt.% sodium hydroxide (NaOH) solution at an elevated temperature. These NPC ribbons are composed of large-sized ligament–pore structures (several hundred nanometers) at outer layers coupled with small-sized those (several ten nanometers) at inner layers. Both large- and small-sized pores are 3D, open and bicontinuous. The formation of the novel NPC ribbons can be well explained based upon the synergetic action between diffusion mechanism and pore size effect. According to the ligament sizes, the surface diffusivities at inner and outer layers of Cu adatoms can be evaluated as 3.80 × 10−20, 1.63 × 10−18, 3.54 × 10−18, 6.83 × 10−18 and 7.88 × 10−20, 5.41 × 10−17, 4.36 × 10−16, 4.27 × 10−15 m2 s−1 for the dealloying at 298, 333, 348 and 363 K, respectively. The activation energies and diffusion constants at inner and outer layers are also measured as 47.7 kJ mol−1, 1.41 × 10−17 m2 s−1 and 145.3 kJ mol−1, 4.21 × 10−14 m2 s−1, suggesting the existence of a complicated dealloying mechanism. Additionally, the length scales of ligaments/pores at inner and outer layers can be modulated by simply changing the dealloying temperature or duration at a fixed elevated temperature.Graphical abstractResearch highlights►We present a one-pot route to fabricate NPC with controlled hierarchical pore size distributions. ►The length scales of ligaments/pores at inner and outer layers of NPC can be easily modulated. ►The surface diffusivities and activation energies at inner and outer layers can be evaluated. ►Some lattice defects during dealloying at an elevated temperature can be formed. ►Superfine single-crystal nanoparticles on the ligament surfaces of NPC can be obtained by dealloying at 90 °C.

Gold nanoparticles supported on activated carbon (Au/C) are prepared by rapid reduction with KBH4, after AuCl4− was partially deposited on the surface of the activated carbon by the reaction of AuCl4− and ammonia. Through the characterization of the transmission electron microscope and X-ray powder diffraction, the mean diameter of the Au nanoparticles (AuNPs) decreases with the increase of the Au loading. The energy dispersive X-ray spectroscopy analysis is carried out for measuring the Au loadings of the Au/C catalysts. The results exhibit the Au/C catalyst with 20 wt% Au has the highest loading efficiency (94.5%). The origin of the catalytic activity of Au/C catalysts for the methanol electrooxidation (MEO) is investigated by the cyclic voltammetry, which indicates that the current densities normalized by the actual Au loading for the MEO increase with a decrease in the mean diameter of AuNPs by a factor of 2.42–3.17. Based on this result, the active sites (corners, edges and step sites) for the MEO are proposed.Highlights► A series of Au/C catalysts with difference Au loadings are prepared by a deposition-reduction process. ► The average size of Au nanoparticles (AuNPs) decreases with the Au loading increasing. ► The Au/C catalyst with 20 wt% Au has the highest loading efficiency (94.5%). ► The active sites for the methanol electrooxidation are the corners, edges and step sites of AuNPs.

It is the first report that the uniformly dispersed nickel oxide nanoparticles were synthesized on the substrates of multi-walled carbon nanotubes (MWNT) via electrochemical technique. The morphology and chemical state of the NiOx/MWNT composite were characterized using scanning electron microscopy and X-ray photoelectron spectroscopy. The electrochemical test results revealed that the surface-decorated composite with oxide particle sizes of 15–30 nm can deliver specific capacitance about 190 F g−1, ten-fold greater than that of pure MWNT. Meanwhile, the electrode displayed excellent cycling stability with nearly 100% coulombic efficiency over 1000 cycles and good rate capability with acceptable specific capacitance fading, indicating that this novel nanostructured composite electrode was a promising candidate for electrochemical capacitors.Highlights► Nickel oxide nanoparticles were electrochemically dispersed on the exterior of MWNT. ► These nanoparticles enhance the specific capacitance of electrodes more than ten-fold. ► Nickel oxide particles dispersed reach specific capacitance ∼1250 F g−1. ► The composite electrodes exhibit excellent rate capability and cyclability.

Gold nanoparticles supported on activated carbon (Au/C) are prepared by rapid reduction of AuCl4− on the surface of activated carbon with KBH4 in the presence of polyvinylpyrrolidone. Through the characterization of the transmission electron microscope, the Au nanoparticles (AuNPs) are highly well dispersed on the carbon support. Cyclic voltammetry, quasi-steady-state polarization, and electrochemical impedance spectroscopy methods are employed to investigate the catalytic activity of the Au/C catalyst for the methanol electro-oxidation (MEO) and the reaction kinetics. The results indicate that the Au/C catalyst shows good catalytic activity toward the MEO, and the weakly adsorbed OH− on the surface of AuNPs has auxiliary catalysis for the MEO. On the basis of this crucially auxiliary catalysis, a novel mechanism of the rate-determining step of the MEO catalyzed by Au/C in alkaline solution is proposed.

Nanoarchitectured Sn–Co alloy electrode was prepared via a facile two-step electrodeposition. With uniform Ni nanocone-array as the substrate, Sn–Co alloy was deposited for 5 min, and densely packed cylinders were formed with semiglobular top. In this configuration, these Ni cones functioned as structure support, electron transport paths, and the inactive confining buffer. Meanwhile, the space between adjacent Sn–Co cylinders as well as the inactive Co matrix accommodated the volume change and cushioned the concomitant internal stress. The nanoarchitectured Sn–Co electrode showed a high discharge capacity of ∼650 mAh g–1, which maintained well with capacity retention of 97.3% after 70 cycles and 83.4% after 90 cycles. It also exhibited attractively high rate capability, delivering high-level capacities at various rates with little capacity decay. These remarkable performances of nanoarchitectured Sn–Co electrode indicated the potential of its application as anode materials for high-performance lithium ion battery.

Poly(pyrrole-co-aniline) (PPyA) copolymer nanofibers were prepared by chemical oxidation method with cetyltrimethyl ammonium chloride (CTAC) as template, and the nano-sulfur/poly(pyrrole-co-aniline) (S/PPyA) composite material in lithium batteries was achieved via co-heating the mixture of PPyA and sublimed sulfur at 160 °C for 24 h. The component and structure of the materials were characterized by FTIR, Raman, XRD, and SEM. PPyA with nanofiber network structure was employed as a conductive matrix, adsorbing agent and firm reaction chamber for the sulfur cathode materials. The nano-dispersed composite exhibited a specific capacity up to 1285 mAh g−1 in the initial cycle and remained 866 mAh g−1 after 40 cycles.

Three-dimensional tin thin-film anode was prepared by electroless plating tin onto three-dimensional (3D) copper foam (which served as current collector), and characterized physically by SEM, EDS and XRD. Its electrochemical property and mechanism were studied by charge–discharge test, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The SEM and EDS results indicated that tin film with 500 nm thickness was formed over the whole surface of copper branches. The XRD results suggested that a new phase of Cu6Sn5 was formed between copper and tin. Besides the tin microflake structure of 500 nm thickness, the interaction effects of the copper foam and Cu6Sn5 phase formed between copper and tin resulted in good cycle performance with first discharge capacity of 737 mAh g−1, 97% capacity retention after 20 cycles and still 84% after 40 cycles.

A Co3O4 nanorod supported Pd electro-catalyst for the methanol electro-oxidation (MEO) has been fabricated by the combination of hydrothermal synthesis and microwave-assisted polyol reduction processes. The crystallographic property and microstructure have been characterized using XRD, SEM and TEM. The results demonstrate that Pd nanoparticles (PdNPs) with a narrow particle size distribution (3–5 nm) are uniformly deposited onto the surface of Co3O4 nanorods. Electrochemical measurements show that this catalyst having a larger electrochemically active surface area and a more negative onset-potential exhibits enhanced catalytic activity of 504 mA/mg Pd for MEO comparing with the Pd/C catalyst (448 mA/mg Pd). The dependency of logI against logv reveals that MEO on Pd-Co3O4 electrode is under a diffusion control. Electrochemical impedance spectroscopy (EIS) measurement agrees well with the CV results. The minimum charge transfer resistance of MEO on Pd-Co3O4 is observed at −0.05 V, which coincides with the potential of MEO peak.Co3O4 nanorods supported Pd nanoparticles electro-catalyst has been successfully fabricated. The kinetics of MEO on the as-prepared catalysts and electrochemical impedance spectroscopy measurements were analyzed.Download full-size image

Pd@Ru bimetallic nanoparticles deposited on carbon black electro-catalysts have been fabricated by microwave-assisted polyol reduction method and investigated for methanol electro-oxidation (MEO). The structure and electro-catalytic properties of the as-prepared catalysts were characterized by XRD, SEM, TEM and cyclic voltammetry (CV) techniques. The results showed that the introduction of Ru element (2–10 wt%) into Pd 20 wt%/C (hereafter, denoted as Pd/C) produced a series of core-shell structured binary catalysts. Pd@Ru 5 wt%/C (hereafter, denoted as Pd@Ru5/C) catalyst displayed the highest catalytic activity towards MEO. And the mass activity of Pd@Ru5/C electrode catalyst at E = −0.038 V (vs. Hg/HgO) was 1.42 times higher than that of Pd/C electrode catalyst. In addition, the relationship between the catalytic stability for MEO on Pd@Ru/C catalysts and the value of Jbp/Jfp (the ratio of MEO peak current density in the negative scan and positive scan) were also investigated. The result demonstrated that Pd@Ru5/C offering the smallest value of Jbp/Jfp displayed the best stable catalytic performance.In this work, we have fabricated binary Pd@Rux (x=2,5,7,10 wt%) nanoparticles deposited on carbon black catalysts and investigated them in electro-catalysis of the MEO in alkaline solution.Download full-size image

Silicon is the most promising anode material to replace graphite in lithium ion batteries due to its high theoretical capacity of 4200 mAh g−1. However, the enormous volume expansion of bulk Si during the lithiation process results in severe electrode degradation and capacity decay. Extensive research effort has been devoted to fabricating nanostructured Si-based materials to improve the capacity cycling stability. Herein, a facile two-step approach is developed for the fabrication of novel three-dimensional (3D) nanoarchitectures composed of polypyrrole–silicon (PPy–Si) core–shell nanofibers. Electropolymerized PPy nanofibers are utilized as the flexible substrate for the deposition of Si thin films via a chemical vapor deposition (CVD) procedure. In this well-designed configuration, the PPy nanofibers are favorable for facile charge delivery and gathering, while the porosity of the electrode can efficiently cushion the volume expansion of Si. The electrode delivers a high reversible capacity above 2800 mAh g−1 with appealing cycling stability (∼91% capacity retained after 100 cycles). The rate capability of the electrode is also remarkable with a high capacity and stability. It is revealed that the reticular nanofibers’ morphology is well preserved after repeated lithium insertion and extraction, which certainly indicates the superiority of our electrode design. This fabrication approach can also be extended to other electrodes for electrochemical energy conversion and storage.

A porous carbon nanofibers/nanosheets hybrid (CNFS) is converted from cornstalk waste by a simple treatment. The resulting material displays a superhigh surface area and rich porosity. Benefiting from unique structural features, the evolved CNFS possesses an ultrahigh rate capability of 454 mA h g−1 at 3 A g−1.

A 3D carbon framework has been introduced into a MnO yolk–shell structure, which functions as an electrical highway and a mechanical framework that improves the reaction kinetics, prevents MnO from fracturing and agglomerating, and limits most SEI formation to the carbon surface instead of on the MnO–electrolyte interface. As a result of this arrangement, the sample demonstrates a maximum reversible specific capacity of 1040 mA h g−1 at rate of 0.2 A g−1 with a long cycle life (without any decrease after 500 cycles), and an outstanding charge/discharge rate capability (513 mA h g−1 at 4 A g−1).