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1.
Fe2O3 is regarded as a promising anode material for lithium‐ion batteries (LIBs) and sodium‐ion batteries (SIBs) due to its high specific capacity. The large volume change during discharge and charge processes, however, induces significant cracking of the Fe2O3 anodes, leading to rapid fading of the capacity. Herein, a novel peapod‐like nanostructured material, consisting of Fe2O3 nanoparticles homogeneously encapsulated in the hollow interior of N‐doped porous carbon nanofibers, as a high‐performance anode material is reported. The distinctive structure not only provides enough voids to accommodate the volume expansion of the pea‐like Fe2O3 nanoparticles but also offers a continuous conducting framework for electron transport and accessible nanoporous channels for fast diffusion and transport of Li/Na‐ions. As a consequence, this peapod‐like structure exhibits a stable discharge capacity of 1434 mAh g?1 (at 100 mA g?1) and 806 mAh g?1 (at 200 mA g?1) over 100 cycles as anode materials for LIBs and SIBs, respectively. More importantly, a stable capacity of 958 mAh g?1 after 1000 cycles and 396 mAh g?1 after 1500 cycles can be achieved for LIBs and SIBs, respectively, at a large current density of 2000 mA g?1. This study provides a promising strategy for developing long‐cycle‐life LIBs and SIBs.  相似文献   

2.
Novel nitrogen doped (N‐doped) hollow beaded structural composite carbon nanofibers are successfully applied for lithium‐ion batteries (LIBs) and sodium‐ion batteries (SIBs). Tungsten disulfide (WS2) nanosheets are confined, through synergistic anchoring, on the surface and inside of hollow beaded carbon nanofibers (HB CNFs) via a hydrothermal reaction method to construct the hierarchical structure HB WS2@CNFs. Benefiting from this unique advantage, HB WS2@CNFs exhibits remarkable lithium‐storage performance in terms of high rate capability (≈351 mAh g?1 at 2 A g?1) and stable long‐term cycle (≈446 mAh g?1 at 1 A g?1 after 100 cycles). Moreover, as an anode material for SIBs, HB WS2@CNFs obtains excellent long cycle life and rate performance. During the charging/discharging process, the evolution of morphology and composition of the composite are analyzed by a set of ex situ methods. This synergistic anchoring effect between WS2 nanosheets and HB CNFs is capable of effectively restraining volume expansion from the metal ions intercalation/deintercalation process and improving the cycling stability and rate performance in LIBs and SIBs.  相似文献   

3.
Research on sodium‐ion batteries (SIBs) has recently been revitalized due to the unique features of much lower costs and comparable energy/power density to lithium‐ion batteries (LIBs), which holds great potential for grid‐level energy storage systems. Transition metal dichalcogenides (TMDCs) are considered as promising anode candidates for SIBs with high theoretical capacity, while their intrinsic low electrical conductivity and large volume expansion upon Na+ intercalation raise the challenging issues of poor cycle stability and inferior rate performance. Herein, the designed formation of hybrid nanoboxes composed of carbon‐protected CoSe2 nanoparticles anchored on nitrogen‐doped carbon hollow skeletons (denoted as CoSe2@C∩NC) via a template‐assisted refluxing process followed by conventional selenization treatment is reported, which exhibits tremendously enhanced electrochemical performance when applied as the anode for SIBs. Specifically, it can deliver a high reversible specific capacity of 324 mAh g?1 at current density of 0.1 A g?1 after 200 cycles and exhibit outstanding high rate cycling stability at the rate of 5 A g?1 over 2000 cycles. This work provides a rational strategy for the design of advanced hybrid nanostructures as anode candidates for SIBs, which could push forward the development of high energy and low cost energy storage devices.  相似文献   

4.
Designing and constructing bimetallic hierarchical structures is vital for the conversion‐alloy reaction anode of sodium‐ion batteries (SIBs). Particularly, the rationally designed hetero‐interface engineering can offer fast diffusion kinetics in the interface, leading to the improved high‐power surface pseudocapacitance and cycling stability for SIBs. Herein, the hierarchical zinc–tin sulfide nanocages (ZnS‐NC/SnS2) are constructed through hydrothermal and sulfuration reactions. The unconventional hierarchical design with internal void space greatly optimizes the structure stability, and bimetallic sulfide brings a bimetallic composite interface and N heteroatom doping, which are devoted to high electrochemical activity and improved interfacial charge transfer rate for Na+ storage. Remarkably, the ZnS‐NC/SnS2 composite anode exhibits a delightful reversible capacity of 595 mAh g?1 after 100 cycles at 0.2 A g?1, and long cycling capability for 500 cycles with a low capacity loss of 0.08% per cycle at 1 A g?1. This study opens up a new route for rationally constructing hierarchical heterogeneous interfaces and sheds new light on efficient anode material for SIBs.  相似文献   

5.
Due to the high theoretical capacity as high as 1494 mAh g?1, SnO2 is considered as a potential anode material for high‐capacity lithium–ion batteries (LIBs). Therefore, the simple but effective method focused on fabrication of SnO2 is imperative. To meet this, a facile and efficient strategy to fabricate core–shell structured C/SnO2 hollow spheres by a solvothermal method is reported. Herein, the solid and hollow structure as well as the carbon content can be controlled. Very importantly, high‐yield C/SnO2 spheres can be produced by this method, which suggest potential business applications in LIBs field. Owing to the dual buffer effect of the carbon layer and hollow structures, the core–shell structured C/SnO2 hollow spheres deliver a high reversible discharge capacity of 1007 mAh g?1 at a current density of 100 mA g?1 after 300 cycles and a superior discharge capacity of 915 mAh g?1 at 500 mA g?1 after 500 cycles. Even at a high current density of 1 and 2 A g?1, the core–shell structured C/SnO2 hollow spheres electrode still exhibits excellent discharge capacity in the long life cycles. Consideration of the superior performance and high yield, the core–shell structured C/SnO2 hollow spheres are of great interest for the next‐generation LIBs.  相似文献   

6.
Carbonaceous materials as anodes usually exhibit low capacity for lithium ion batteries (LIBs) and sodium ion batteries (SIBs). Oxygen‐doped carbonaceous materials have the potential of high capacity and super rate performance. However, up to now, the reported oxygen‐doped carbonaceous materials usually exhibit inferior electrochemical performance. To overcome this problem, a high reactive oxygen‐doped 3D interdigital porous carbonaceous material is designed and synthesized through epitaxial growth method and used as anodes for LIBs and SIBs. It delivers high reversible capacity, super rate performance, and long cycling stability (473 mA h g?1after 500 cycles for LIBs and 223 mA h g?1 after 1200 cycles for SIBs, respectively, at the current density of 1000 mA g?1), with a capacity decay of 0.0214% per cycle for LIBs and 0.0155% per cycle for SIBs. The results demonstrate that constructing 3D interdigital porous structure with reactive oxygen functional groups can significantly enhance the electrochemical performance of oxygen‐doped carbonaceous material.  相似文献   

7.
Exploitation of high‐performance anode materials is essential but challenging to the development of sodium‐ion batteries (SIBs). Among all proposed anode materials for SIBs, sulfides have been proved promising candidates due to their unique chemical and physical properties. In this work, a facile solvothermal method to in situ decorate cobalt sulfide (CoS) nanoplates on reduced graphene oxide (rGO) to build CoS@rGO composite is described. When evaluated as anode for SIBs, an impressive high specific capacity (540 mAh g?1 at 1 A g?1), excellent rate capability (636 mAh g?1 at 0.1 A g?1 and 306 mAh g?1 at 10 A g?1), and extraordinarily cycle stability (420 mAh g?1 at 1 A g?1 after 1000 cycles) have been demonstrated by CoS@rGO composite for sodium storage. The synergetic effect between the CoS nanoplates and rGO matrix contributes to the enhanced electrochemical performance of the hybrid composite. The results provide a facile approach to fabricate promising anode materials for high‐performance SIBs.  相似文献   

8.
Building a rechargeable battery with high capacity, high energy density, and long lifetime contributes to the development of novel energy storage devices in the future. Although carbon materials are very attractive anode materials for lithium‐ion batteries (LIBs), they present several deficiencies when used in sodium‐ion batteries (SIBs). The choice of an appropriate structural design and heteroatom doping are critical steps to improve the capacity and stability. Here, carbon‐based nanofibers are produced by sulfur doping and via the introduction of ultrasmall TiO2 nanoparticles into the carbon fibers (CNF‐S@TiO2). It is discovered that the introduction of TiO2 into carbon nanofibers can significantly improve the specific surface area and microporous volume for carbon materials. The TiO2 content is controlled to obtain CNF‐S@TiO2‐5 to use as the anode material for SIBs/LIBs with enhanced electrochemical performance in Na+/Li+ storage. During the charge/discharge process, the S‐doping and the incorporation of TiO2 nanoparticles into carbon fibers promote the insertion/extraction of the ions and enhance the capacity and cycle life. The capacity of CNF‐S@TiO2‐5 can be maintained at ≈300 mAh g?1 over 600 cycles at 2 A g?1 in SIBs. Moreover, the capacity retention of such devices is 94%, showing high capacity and good stability.  相似文献   

9.
High energy density is the major demand for next‐generation rechargeable batteries, while the intrinsic low alkali metal adsorption of traditional carbon–based electrode remains the main challenge. Here, the mechanochemical route is proposed to prepare nitrogen doped γ‐graphyne (NGY) and its high capacity is demonstrated in lithium (LIBs)/sodium (SIBs) ion batteries. The sample delivers large reversible Li (1037 mAh g?1) and Na (570.4 mAh g?1) storage capacities at 100 mA g?1 and presents excellent rate capabilities (526 mAh g?1 for LIBs and 180.2 mAh g?1 for SIBs) at 5 A g?1. The superior Li/Na storage mechanisms of NGY are revealed by its 2D morphology evolution, quantitative kinetics, and theoretical calculations. The effects on the diffusion barriers (Eb) and adsorption energies (Ead) of Li/Na atoms in NGY are also studied and imine‐N is demonstrated to be the ideal doping format to enhance the Li/Na storage performance. Besides, the Li/Na adsorption routes in NGY are optimized according to the experimental and the first‐principles calculation results. This work provides a facile way to fabricate high capacity electrodes in LIBs/SIBs, which is also instructive for the design of other heteroatomic doped electrodes.  相似文献   

10.
Lithium‐ion batteries (LIBs) have been widely applied and studied as an effective energy supplement for a variety of electronic devices. Titanium dioxide (TiO2), with a high theoretical capacity (335 mAh g?1) and low volume expansion ratio upon lithiation, has been considered as one of the most promising anode materials for LIBs. However, the application of TiO2 is hindered by its low electrical conductivity and slow ionic diffusion rate. Herein, a 2D ultrathin mesoporous TiO2/reduced graphene (rGO) heterostructure is fabricated via a layer‐by‐layer assembly process. The synergistic effect of ultrathin mesoporous TiO2 and the rGO nanosheets significantly enhances the ionic diffusion and electron conductivity of the composite. The introduced 2D mesoporous heterostructure delivers a significantly improved capacity of 350 mAh g?1 at a current density of 200 mA g?1 and excellent cycling stability, with a capacity of 245 mAh g?1 maintained over 1000 cycles at a high current density of 1 A g?1. The in situ transmission electron microscopy analysis indicates that the volume of the as‐prepared 2D heterostructures changes slightly upon the insertion and extraction of Li+, thus contributing to the enhanced long‐cycle performance.  相似文献   

11.
Sodium‐ion batteries (SIBs) have gained tremendous interest for grid scale energy storage system and power energy batteries. However, the current researches of anode for SIBs still face the critical issues of low areal capacity, limited cycle life, and low initial coulombic efficiency for practical application perspective. To solve this issue, a kind of hierarchical 3D carbon‐networks/Fe7S8/graphene (CFG) is designed and synthesized as freestanding anode, which is constructed with Fe7S8 microparticles well‐welded on 3D‐crosslinked carbon‐networks and embedded in highly conductive graphene film, via a facile and scalable synthetic method. The as‐prepared freestanding electrode CFG represents high areal capacity (2.12 mAh cm?2 at 0.25 mA cm?2) and excellent cycle stability of 5000 cycles (0.0095% capacity decay per cycle). The assembled all‐flexible sodium‐ion battery delivers remarkable performance (high areal capacity of 1.42 mAh cm?2 at 0.3 mA cm?2 and superior energy density of 144 Wh kg?1), which are very close to the requirement of practical application. This work not only enlightens the material design and electrode engineering, but also provides a new kind of freestanding high energy density anode with great potential application prospective for SIBs.  相似文献   

12.
SnO2‐based lithium‐ion batteries have low cost and high energy density, but their capacity fades rapidly during lithiation/delithiation due to phase aggregation and cracking. These problems can be mitigated by using highly conducting black SnO2?x , which homogenizes the redox reactions and stabilizes fine, fracture‐resistant Sn precipitates in the Li2O matrix. Such fine Sn precipitates and their ample contact with Li2O proliferate the reversible Sn → Li x Sn → Sn → SnO2/SnO2?x cycle during charging/discharging. SnO2?x electrode has a reversible capacity of 1340 mAh g?1 and retains 590 mAh g?1 after 100 cycles. The addition of highly conductive, well‐dispersed reduced graphene oxide further stabilizes and improves its performance, allowing 950 mAh g?1 remaining after 100 cycles at 0.2 A g?1 with 700 mAh g?1 at 2.0 A g?1. Conductivity‐directed microstructure development may offer a new approach to form advanced electrodes.  相似文献   

13.
Alloy anodes have shown great potential for next‐generation lithium‐ion batteries (LIBs) and sodium‐ion batteries (SIBs). However, these applications are still limited by inherent huge volume changes and sluggish kinetics. To overcome such limitations, graphene‐protected 3D Sb‐based anodes grown on conductive substrate are designed and fabricated by a facile electrostatic‐assembling and subsequent confinement replacement strategy. As binder‐free anodes for LIBs, the obtained electrode exhibits reversible capacities of 442 mAh g−1 at 100 mA g−1 and 295 mAh g−1 at 1000 mA g−1, and a capacity retention of above 90% (based on the 10th cycle) after 200 cycles at 500 mA g−1. As for sodium storage properties, the reversible capacities of 517 mAh g−1 at 50 mA g−1 and 315 mAh g−1 at 1000 mA g−1, the capacity retention of 305 mAh g−1 after 100 cycles at 300 mA g−1 are obtained, respectively. Furthermore, the 3D architecture retains good structural integrity after cycling, confirming that the introduction of high‐stretchy and robust graphene layers can effectively buffer alloying anodes, and simultaneously provide sustainable contact and protection of the active materials. Such findings show its great potential as superior binder‐free anodes for LIBs and SIBs.  相似文献   

14.
Tin dioxide (SnO2) has attracted much attention in lithium‐ion batteries (LIBs) due to its abundant source, low cost, and high theoretical capacity. However, the large volume variation, irreversible conversion reaction limit its further practical application in next‐generation LIBs. Here, a novel solvent‐free approach to construct uniform metal–organic framework (MOF) shell‐derived carbon confined SnO2/Co (SnO2/Co@C) nanocubes via a two‐step heat treatment is developed. In particular, MOF‐coated CoSnO3 hollow nanocubes are for the first time synthesized as the intermediate product by an extremely simple thermal solid‐phase reaction, which is further developed as a general strategy to successfully obtain other uniform MOF‐coated metal oxides. The as‐synthesized SnO2/Co@C nanocubes, when tested as LIB anodes, exhibit a highly reversible discharge capacity of 800 mAh g?1 after 100 cycles at 200 mA g?1 and excellent cycling stability with a retained capacity of 400 mAh g?1 after 1800 cycles at 5 A g?1. The experimental analyses demonstrate that these excellent performances are mainly ascribed to the delicate structure and a synergistic effect between Co and SnO2. This facile synthetic approach will greatly contribute to the development of functional metal oxide‐based and MOF‐assisted nanostructures in many frontier applications.  相似文献   

15.
Silicon holds great promise as an anode material for lithium‐ion batteries with higher energy density; its implication, however, is limited by rapid capacity fading. A catalytic growth of graphene cages on composite particles of magnesium oxide and silicon, which are made by magnesiothermic reduction reaction of silica particles, is reported herein. Catalyzed by the magnesium oxide, graphene cages can be conformally grown onto the composite particles, leading to the formation of hollow graphene‐encapsulated Si particles. Such materials exhibit excellent lithium storage properties in terms of high specific capacity, remarkable rate capability (890 mAh g?1 at 5 A g?1), and good cycling retention over 200 cycles with consistently high coulombic efficiency at a current density of 1 A g?1. A full battery test using LiCoO2 as the cathode demonstrates a high energy density of 329 Wh kg?1.  相似文献   

16.
It is indispensable to develop and design high capacity, high rate performance, long cycling life, and low-cost electrodes materials for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). Herein, MoO2/MoS2/C, with dual heterogeneous interfaces, is designed to induce a built-in electric field, which has been proved by experiments and theoretical calculation can accelerate electrochemical reaction kinetics and generate interfacial interactions to strengthen structural stability. The carbon foam serves as a conductive frame to assist the movement of electrons/ions, as well as forms heterogeneous interfaces with MoO2/MoS2 through C S and C O bonds, maintaining structural integrity and enhancing electronic transport. Thanks to these unique characteristics, the MoO2/MoS2/C renders a significantly enhanced electrochemical performance (324 mAh g−1 at 1 A g−1 after 1000 cycles for SIB and 500 mAh g−1 at 1 A g−1 after 500 cycles for LIBs). The current work presents a simple, useful and cost-effective route to design high-quality electrodes via interfacial engineering.  相似文献   

17.
SnS2 has been widely studied as an anode material for sodium‐ion batteries (SIBs) based on the high theoretical capacity and layered structure. Unfortunately, rapid capacity decay associated with volume variation during cycling limits practical application. Herein, SnS2/Co3S4 hollow nanocubes anchored on S‐doped graphene are synthesized for the first time via coprecipitation and hydrothermal methods. When applied as the anode for SIBs, the sample delivers a distinguished charge specific capacity of 1141.8 mAh g?1 and there is no significant capacity decay (0.1 A g?1 for 50 cycles). When the rate is increased to 0.5 A g?1, it presents 845.7 mAh g?1 after cycling 100 times. Furthermore, the composite also exhibits an ultrafast sodium storage capability where 392.9 mAh g?1 can be obtained at 10 A g?1 and the charging time is less than 3 min. The outstanding electrochemical properties can be ascribed to the enhancement of conductivity for the addition of S‐doped graphene and the existence of p–n junctions in the SnS2/Co3S4 heterostructure. Moreover, the presence of mesopores between nanosheets can alleviate volume expansion during cycling as well as being beneficial for the migration of Na+.  相似文献   

18.
1T phase MoS2 possesses higher conductivity than the 2H phase, which is a key parameter of electrochemical performance for lithium ion batteries (LIBs). Herein, a 1T‐MoS2/C hybrid is successfully synthesized through facile hydrothermal method with a proper glucose additive. The synthesized hybrid material is composed of smaller and fewer‐layer 1T‐MoS2 nanosheets covered by thin carbon layers with an enlarged interlayer spacing of 0.94 nm. When it is used as an anode material for LIBs, the enlarged interlayer spacing facilitates rapid intercalating and deintercalating of lithium ions and accommodates volume change during cycling. The high intrinsic conductivity of 1T‐MoS2 also contributes to a faster transfer of lithium ions and electrons. Moreover, much smaller and fewer‐layer nanosheets can shorten the diffusion path of lithium ions and accelerate reaction kinetics, leading to an improved electrochemical performance. It delivers a high initial capacity of 920.6 mAh g?1 at 1 A g?1 and the capacity can maintain 870 mAh g?1 even after 300 cycles, showing a superior cycling stability. The electrode presents a high rate performance as well with a reversible capacity of 600 mAh g?1 at 10 A g?1. These results show that the 1T‐MoS2/C hybrid shows potential for use in high‐performance lithium‐ion batteries.  相似文献   

19.
Molybdenum disulfide (MoS2) is a promising anode for high performance sodium‐ion batteries due to high specific capacity, abundance, and low cost. However, poor cycling stability, low rate capability and unclear electrochemical reaction mechanism are the main challenges for MoS2 anode in Na‐ion batteries. In this study, molybdenum disulfide/carbon (MoS2/C) nanospheres are fabricated and used for Na‐ion battery anodes. MoS2/C nanospheres deliver a reversible capacity of 520 mAh g?1 at 0.1 C and maintain at 400 mAh g?1 for 300 cycles at a high current density of 1 C, demonstrating the best cycling performance of MoS2 for Na‐ion batteries to date. The high capacity is attributed to the short ion and electron diffusion pathway, which enables fast charge transfer and low concentration polarization. The stable cycling performance and high coulombic efficiency (~100%) of MoS2/C nanospheres are ascribed to (1) highly reversible conversion reaction of MoS2 during sodiation/desodiation as evidenced by ex‐situ X‐ray diffraction (XRD) and (2) the formation of a stable solid electrolyte interface (SEI) layer in fluoroethylene carbonate (FEC) based electrolyte as demonstrated by fourier transform infrared spectroscopy (FTIR) measurements.  相似文献   

20.
Recently, binary ZnCo2O4 has drawn enormous attention for lithium‐ion batteries (LIBs) as attractive anode owing to its large theoretical capacity and good environmental benignity. However, the modest electrical conductivity and serious volumetric effect/particle agglomeration over cycling hinder its extensive applications. To address the concerns, herein, a rapid laser‐irradiation methodology is firstly devised toward efficient synthesis of oxygen‐vacancy abundant nano‐ZnCo2O4/porous reduced graphene oxide (rGO) hybrids as anodes for LIBs. The synergistic contributions from nano‐dimensional ZnCo2O4 with rich oxygen vacancies and flexible rGO guarantee abundant active sites, fast electron/ion transport, and robust structural stability, and inhibit the agglomeration of nanoscale ZnCo2O4, favoring for superb electrochemical lithium‐storage performance. More encouragingly, the optimal L‐ZCO@rGO‐30 anode exhibits a large reversible capacity of ≈1053 mAh g?1 at 0.05 A g?1, excellent cycling stability (≈746 mAh g?1 at 1.0 A g?1 after 250 cycles), and preeminent rate capability (≈686 mAh g?1 at 3.2 A g?1). Further kinetic analysis corroborates that the capacitive‐controlled process dominates the involved electrochemical reactions of hybrid anodes. More significantly, this rational design holds the promise of being extended for smart fabrication of other oxygen‐vacancy abundant metal oxide/porous rGO hybrids toward advanced LIBs and beyond.  相似文献   

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