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In situ weaving an all‐carbon graphdiyne coat on a silicon anode is scalably realized under ultralow temperature (25 °C). This economical strategy not only constructs 3D all‐carbon mechanical and conductive networks with reasonable voids for the silicon anode at one time but also simultaneously forms a robust interfacial contact among the electrode components. The intractable problems of the disintegrations in the mechanical and conductive networks and the interfacial contact caused by repeated volume variations during cycling are effectively restrained. The as‐prepared electrode demostrates the advantages of silicon regarding capacity (4122 mA h g?1 at 0.2 A g?1) with robust capacity retention (1503 mA h g?1) after 1450 cycles at 2 A g?1, and a commercial‐level areal capacity up to 4.72 mA h cm?2 can be readily approached. Furthermore, this method shows great promises in solving the key problems in other high‐energy‐density anodes.  相似文献   

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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   

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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   

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Liquid phase exfoliation of few‐layer phosphorene (FL‐P) is extensively explored in recent years. Nevertheless, their deficiencies such as ultralong sonication time, limited flake size distribution, and uncontrollable thicknesses are major hurdles for the development of phosphorene‐based materials. Herein, electrochemical cationic intercalation has been introduced to prepare phosphorene, through which large‐area FL‐P without surface functional groups can be efficiently attained (less than 1 h). More importantly, its layer number (from 2 to 11 layers) can be manipulated by changing the applied potential. The as‐obtained phosphorene delivers superior sodium‐storage performances when directly utilized as an anode material in sodium‐ion batteries. This electrochemical cation insertion method to prepare phosphorene should greatly facilitate the development of phosphorene‐based technologies. Moreover, this work provides the possibility for the scalable preparation of monolayer 2D materials by exploring intercalation ions. Additionally, the successful electrochemical exfoliation of phosphorene can promote the application of electrochemical exfoliation in other 2D materials.  相似文献   

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Molybdenum ditelluride nanosheets encapsulated in few‐layer graphene (MoTe2/FLG) are synthesized by a simple heating method using Te and Mo powder and subsequent ball milling with graphite. The as‐prepared MoTe2/FLG nanocomposites as anode materials for lithium‐ion batteries exhibit excellent electrochemical performance with a highly reversible capacity of 596.5 mAh g?1 at 100 mA g?1, a high rate capability (334.5 mAh g?1 at 2 A g?1), and superior cycling stability (capacity retention of 99.5% over 400 cycles at 0.5 A g?1). Ex situ X‐ray diffraction and transmission electron microscopy are used to explore the lithium storage mechanism of MoTe2. Moreover, the electrochemical performance of a MoTe2/FLG//0.35Li2MnO3·0.65LiMn0.5Ni0.5O2 full cell is investigated, which displays a reversible capacity of 499 mAh g?1 (based on the MoTe2/FLG mass) at 100 mA g?1 and a capacity retention of 78% over 50 cycles, suggesting the promising application of MoTe2/FLG for lithium‐ion storage. First‐principles calculations exhibit that the lowest diffusion barrier (0.18 eV) for lithium ions along pathway III in the MoTe2 layered structure is beneficial for improving the Li intercalation/deintercalation property.  相似文献   

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Novel layered 2D frameworks (C3N and C2N‐450) with well‐defined crystal structures are explored for use as anode materials in lithium‐ion batteries (LIBs) for the first time. As anode materials for LIBs, C3N and C2N‐450 exhibit unusual electrochemical characteristics. For example, C2N‐450 (and C3N) display high reversible capacities of 933.2 (383.3) and 40.1 (179.5) mAh g?1 at 0.1 and 10 C, respectively. Furthermore, C3N shows a low hypothetical voltage (≈0.15 V), efficient operating voltage window with ≈85% of full discharge capacity secured at >0.45 V, and excellent cycling stability for more than 500 cycles. The excellent electrochemical performance (especially of C3N) can be attributed to their inherent 2D polyaniline frameworks, which provide large net positive charge densities, excellent structural stability, and enhanced electronic/ionic conductivity. Stable solid state interface films also form on the surfaces of the 2D materials during the charge/discharge process. These 2D materials with promising electrochemical performance should provide insights to guide the design and development of their analogues for future energy applications.  相似文献   

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Titanium‐based oxides including TiO2 and M‐Ti‐O compounds (M = Li, Nb, Na, etc.) family, exhibit advantageous structural dynamics (2D ion diffusion path, open and stable structure for ion accommodations) for practical applications in energy storage systems, such as lithium‐ion batteries, sodium‐ion batteries, and hybrid pseudocapacitors. Further, Ti‐based oxides show high operating voltage relative to the deposition of alkali metal, ensuring full safety by avoiding the formation of lithium and sodium dendrites. On the other hand, high working potential prevents the decomposition of electrolyte, delivering excellent rate capability through the unique pseudocapacitive kinetics. Nevertheless, the intrinsic poor electrical conductivity and reaction dynamics limit further applications in energy storage devices. Recently, various work and in‐depth understanding on the morphologies control, surface engineering, bulk‐phase doping of Ti‐based oxides, have been promoted to overcome these issues. Inspired by that, in this review, the authors summarize the fundamental issues, challenges and advances of Ti‐based oxides in the applications of advanced electrochemical energy storage. Particularly, the authors focus on the progresses on the working mechanism and device applications from lithium‐ion batteries to sodium‐ion batteries, and then the hybrid pseudocapacitors. In addition, future perspectives for fundamental research and practical applications are discussed.  相似文献   

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O3‐type NaNi1/3Fe1/3Mn1/3O2 (NaNFM) is well investigated as a promising cathode material for sodium‐ion batteries (SIBs), but the cycling stability of NaNFM still needs to be improved by using novel electrolytes or optimizing their structure with the substitution of different elements sites. To enlarge the alkali‐layer distance inside the layer structure of NaNFM may benefit Na+ diffusion. Herein, the effect of Ca‐substitution is reported in Na sites on the structural and electrochemical properties of Na1?xCax/2NFM (x = 0, 0.05, 0.1). X‐ray diffraction (XRD) patterns of the prepared Na1?xCax/2NFM samples show single α‐NaFeO2 type phase with slightly increased alkali‐layer distance as Ca content increases. The cycling stabilities of Ca‐substituted samples are remarkably improved. The Na0.9Ca0.05Ni1/3Fe1/3Mn1/3O2 (Na0.9Ca0.05NFM) cathode delivers a capacity of 116.3 mAh g?1 with capacity retention of 92% after 200 cycles at 1C rate. In operando XRD indicates a reversible structural evolution through an O3‐P3‐P3‐O3 sequence of Na0.9Ca0.05NFM cathode during cycling. Compared to NaNMF, the Na0.9Ca0.05NFM cathode shows a wider voltage range in pure P3 phase state during the charge/discharge process and exhibits better structure recoverability after cycling. The superior cycling stability of Na0.9Ca0.05NFM makes it a promising material for practical applications in sodium‐ion batteries.  相似文献   

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2D Sulfur‐doped TiSe2/Fe3O4 (named as S‐TiSe2/Fe3O4) heterostructures are synthesized successfully based on a facile oil phase process. The Fe3O4 nanoparticles, with an average size of 8 nm, grow uniformly on the surface of S‐doped TiSe2 (named as S‐TiSe2) nanoplates (300 nm in diameter and 15 nm in thickness). These heterostructures combine the advantages of both S‐TiSe2 with good electrical conductivity and Fe3O4 with high theoretical Li storage capacity. As demonstrated potential applications for energy storage, the S‐TiSe2/Fe3O4 heterostructures possess high reversible capacities (707.4 mAh g−1 at 0.1 A g−1 during the 100th cycle), excellent cycling stability (432.3 mAh g−1 after 200 cycles at 5 A g−1), and good rate capability (e.g., 301.7 mAh g−1 at 20 A g−1) in lithium‐ion batteries. As for sodium‐ion batteries, the S‐TiSe2/Fe3O4 heterostructures also maintain reversible capacities of 402.3 mAh g−1 at 0.1 A g−1 after 100 cycles, and a high rate capacity of 203.3 mAh g−1 at 4 A g−1.  相似文献   

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Metal oxide nanosheets have attracted great attention in various fields, such as energy storage, catalysis, and sensors. Current synthesis methods of metal oxide nanosheets are laborious and not scalable. Herein, a facile and scalable method for the synthesis of metal oxide nanosheets is presented, which requires neither hydro‐/solvothermal conditions nor postsynthesis template removal. The synthesis is versatile, as evidenced by the wide variety of metal oxide nanosheets derived. Nanosheet properties such as crystallinity, crystallite size, and carbon content can be controlled by tuning the synthesis conditions. The metal oxide nanosheets demonstrate promising performance as Li‐ion battery anodes.  相似文献   

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The leaf-like structure is a classic and robust structure and its unique vein support can reduce structural instability. However, biomimetic leaf structures on the atomic scale are rarely reported due to the difficulty in achieving a stable vein-like support in a mesophyll-like substrate. A breathable 2D MnO2 artificial leaf is first reported with atomic thickness by using a simple and mild one-step wet chemical method. This homogeneous ultrathin leaf-like structure comprises of vein-like crystalline skeleton as support and amorphous microporous mesophyll-like nanosheet as substrate. When used as an anode material for lithium ion batteries, it first solves the irreversible capacity loss and poor cycling issue of pure MnO2, which delivers high capacity of 1210 mAh g−1 at 0.1 A g−1 and extremely stable cycle life over 2500 cycles at 1.0 A g−1. It exhibits the most outstanding cycle life of pure MnO2 and even comparable to the most MnO2-based composite electrode materials. This biomimetic design provides important guidelines for precise control of 2D artificial systems and gives a new idea for solving poor electrochemical stability of pure metal oxide electrode materials.  相似文献   

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Stretchable energy‐storage devices receive considerable attention due to their promising applications in future wearable technologies. However, they currently suffer from many problems, including low utility of active materials, limited multidirectional stretchability, and poor stability under stretched conditions. In addition, most proposed designs use one or more rigid components that fail to meet the stretchability requirement for the entire device. Here, an all‐stretchable‐component sodium‐ion full battery based on graphene‐modified poly(dimethylsiloxane) sponge electrodes and an elastic gel membrane is developed for the first time. The battery exhibits reasonable electrochemical performance and robust mechanical deformability; its electrochemical characteristics can be well‐maintained under many different stretched conditions and after hundreds of stretching–release cycles. This novel design integrating all stretchable components provides a pathway toward the next generation of wearable energy devices in modern electronics.  相似文献   

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Secondary charge batteries have captured numerous attentions, owing to their abundant raw, portability, and high energy density. As the main ions‐storage carrier, the electrode materials serve vital roles on the properties of whole battery system. Currently, MoSe2 is regarded as rising star of transition metal dichalcogenides, displaying unique layered structure, high electronic conductivity, as well as narrow energy band. These advantages enable their widely application on hydrogen evolution reactions and solar cells. Recently, a plenty of researching activities on MoSe2/carbon are triggered due to large interplanar spacing and high ions/e− migration rate. In this review, the recent achievements of diverse MoSe2/carbon on great energy‐storage domains are solidly summarized from bonding types (surface‐loading, internal‐wrapped) and dimensional controlling (1D nanotubes/nanofibers, 2D graphene/nanosheets, 3D carbon framework/sphere). Meanwhile, the related Li/Na ions‐storage mechanisms are also concluded. Furthermore, for MoSe2/carbon with better electrochemical properties, the opportunities and perspectives in the future are also suggested. This review throws light on the systematic developments of advanced MoSe2/carbon, and confirms its exploring potential on lithium‐ion batteries/sodium‐ion batteries.  相似文献   

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A reduced graphene oxide (rGO)‐based 3D architecture with unique flower‐like cobalt oxide microstructures, uniformly embedded in a graphene hydrogel matrix (CoO–GHG) resulting in completely interconnected structures, is fabricated. The self‐assembled 3D architecture with improved porosity and conductivity exhibits excellent electrochemical performance as an anode for lithium‐ion batteries, with high reversible specific capacity (1010 mAh g−1 over 100 cycles), a long cycling lifetime, and good rate capability. The exceptional performance results from the unique 3D structure of the hybrid CoO–GHG, with highly dispersed flower‐like CoO on a conducting graphene network, providing more accessible surface sites for large lithiation/delithiation with minimum volume expansion and imparting good conductivity and short diffusion length for Li+ ions. Electrochemical studies demonstrate that these 3D architectured electrodes are promising as efficient anodes for high‐performance lithium‐ion battery devices.  相似文献   

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Graphene–molybdenum sulfide composite materials are attracting considerable interest as a promising candidate of anode for lithium‐ion batteries because of their excellent electrical properties. However, few studies have been conducted on the lithium‐storage mechanism and process of dynamics of these materials. In this work, the lithium‐storage mechanism of these materials is examined by structural characterization and kinetic analysis. Structural characterization results show that the prepared G/MoS2 is a heterostructure and contains C S bonds after treatment with a novel layered graphene oxide‐assisted ultrasonic method. The existence of C S bond benefits the transport of lithium ion and electrons and enhances the electrochemical properties of G/MoS2 electrode. Kinetic analysis further reveals that the lithium‐ion diffusion effect plays a major role in charge and discharge processes. This synthesis method and analysis strategy may also apply to other composite materials for high‐performance lithium‐ion storage.  相似文献   

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Preventing the aggregation of nanosized electrode materials is a key point to fully utilize the advantage of the high capacity. In this work, a facile and low‐cost surface solvation treatment is developed to synthesize Fe2VO4 hierarchical porous microparticles, which efficiently prevents the aggregation of the Fe2VO4 primary nanoparticles. The reaction between alcohol molecules and surface hydroxy groups is confirmed by density functional theory calculations and Fourier transform infrared spectroscopy. The electrochemical mechanism of Fe2VO4 as lithium‐ion battery anode is characterized by in situ X‐ray diffraction for the first time. This electrode material is capable of delivering a high reversible discharge capacity of 799 mA h g?1 at 0.5 A g?1 with a high initial coulombic efficiency of 79%, and the capacity retention is 78% after 500 cycles. Moreover, a remarkable reversible discharge capacity of 679 mA h g?1 is achieved at 5 A g?1. Furthermore, when tested as sodium‐ion battery anode, a high reversible capacity of 382 mA h g?1 can be delivered at the current density of 1 A g?1, which still retains at 229 mA h g?1 after 1000 cycles. The superior electrochemical performance makes it a potential anode material for high‐rate and long‐life lithium/sodium‐ion batteries.  相似文献   

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