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1.
Lithium‐ion, sodium‐ion, and potassium‐ion batteries have captured tremendous attention in power supplies for various electric vehicles and portable electronic devices. However, their practical applications are severely limited by factors such as poor rate capability, fast capacity decay, sluggish charge storage dynamics, and low reversibility. Herein, hetero‐structured bimetallic sulfide (NiS/FeS) encapsulated in N‐doped porous carbon cubes interconnected with CNTs (Ni‐Fe‐S‐CNT) are prepared through a convenient co‐precipitation and post‐heat treatment sulfurization technique of the corresponding Prussian‐blue analogue nanocage precursor. This special 3D hierarchical structure can offer a stable interconnect and conductive network and shorten the diffusion path of ions, thereby greatly enhancing the mobility efficiency of alkali (Li, Na, K) ions in electrode materials. The Ni‐Fe‐S‐CNT nanocomposite maintains a charge capacity of 1535 mAh g?1 at 0.2 A g?1 for lithium ion batteries, 431 mAh g?1 at 0.1 A g?1 for sodium ion batteries, and 181 mAh g?1 at 0.1 A g?1 for potassium‐ion batteries, respectively. The high performance is mainly attributed to the 3D hierarchically high‐conductivity network architecture, in which the hetero‐structured FeS/NiS nanocubes provide fast Li+/Na+/K+ insertion/extraction and reduced ion diffusion paths, and the distinctive 3D networks maintain the electrical contact and guarantee the structural integrity.  相似文献   

2.
Metal oxide‐based nanomaterials are widely studied because of their high‐energy densities as anode materials in lithium‐ion batteries. However, the fast capacity degradation resulting from the large volume expansion upon lithiation hinders their practical application. In this work, the preparation of walnut‐like multicore–shell MnO encapsulated nitrogen‐rich carbon nanocapsules (MnO@NC) is reported via a facile and eco‐friendly process for long‐cycling Li‐ion batteries. In this hybrid structure, MnO nanoparticles are uniformly dispersed inside carbon nanoshells, which can simultaneously act as a conductive framework and also a protective buffer layer to restrain the volume variation. The MnO@NC nanocapsules show remarkable electrochemical performances for lithium‐ion batteries, exhibiting high reversible capability (762 mAh g?1 at 100 mA g?1) and stable cycling life (624 mAh g?1 after 1000 cycles at 1000 mA g?1). In addition, the soft‐packed full batteries based on MnO@NC nanocapsules anodes and commercial LiFePO4 cathodes present good flexibility and cycling stability.  相似文献   

3.
Sodium‐ion batteries (SIBs) are considered as promising alternatives to lithium‐ion batteries (LIBs) for energy storage due to the abundance of sodium, especially for grid distribution systems. The practical implementation of SIBs, however, is severely hindered by their low energy density and poor cycling stability due to the poor electrochemical performance of the existing electrodes. Here, to achieve high‐capacity and durable sodium storage with good rate capability, hierarchical hollow NiS spheres with porous shells composed of nanoparticles are designed and synthesized by tuning the reaction parameters. The formation mechanism of this unique structure is systematically investigated, which is clearly revealed to be Ostwald ripening mechanism on the basis of the time‐dependent morphology evolution. The hierarchical hollow structure provides sufficient electrode/electrolyte contact, shortened Na+ diffusion pathways, and high strain‐tolerance capability. The hollow NiS spheres deliver high reversible capacity (683.8 mAh g?1 at 0.1 A g?1), excellent rate capability (337.4 mAh g?1 at 5 A g?1), and good cycling stability (499.9 mAh g?1 with 73% retention after 50 cycles at 0.1 A g?1).  相似文献   

4.
Li‐ion hybrid capacitors (LIHCs), consisting of an energy‐type redox anode and a power‐type double‐layer cathode, are attracting significant attention due to the good combination with the advantages of conventional Li‐ion batteries and supercapacitors. However, most anodes are battery‐like materials with the sluggish kinetics of Li‐ion storage, which seriously restrict the energy storage of LIHCs at the high charge/discharge rates. Herein, vanadium nitride (VN) nanowire is demonstated to have obvious pseudocapacitive characteristic of Li‐ion storage and can get further gains in energy storage through a 3D porous architecture with the assistance of conductive reduced graphene oxide (RGO). The as‐prepared 3D VN–RGO composite exhibits the large Li‐ion storage capacity and fast charge/discharge rate within a wide working widow from 0.01–3 V (vs Li/Li+), which could potentially boost the operating potential and the energy and power densities of LIHCs. By employing such 3D VN–RGO composite and porous carbon nanorods with a high surface area of 3343 m2 g?1 as the anode and cathode, respectively, a novel LIHCs is fabricated with an ultrahigh energy density of 162 Wh kg?1 at 200 W kg?1, which also remains 64 Wh kg?1 even at a high power density of 10 kW kg?1.  相似文献   

5.
The lithium–sulfur (Li–S) battery is regarded as the most promising rechargeable energy storage technology for the increasing applications of clean energy transportation systems due to its remarkable high theoretical energy density of 2.6 kWh kg?1, considerably outperforming today's lithium‐ion batteries. Additionally, the use of sulfur as active cathode material has the advantages of being inexpensive, environmentally benign, and naturally abundant. However, the insulating nature of sulfur, the fast capacity fading, and the short lifespan of Li–S batteries have been hampered their commercialization. In this paper, a functional mesoporous carbon‐coated separator is presented for improving the overall performance of Li–S batteries. A straightforward coating modification of the commercial polypropylene separator allows the integration of a conductive mesoporous carbon layer which offers a physical place to localize dissolved polysulfide intermediates and retain them as active material within the cathode side. Despite the use of a simple sulfur–carbon black mixture as cathode, the Li–S cell with a mesoporous carbon‐coated separator offers outstanding performance with an initial capacity of 1378 mAh g?1 at 0.2 C, and high reversible capacity of 723 mAh g?1, and degradation rate of only 0.081% per cycle, after 500 cycles at 0.5 C.  相似文献   

6.
On account of increasing demand for energy storage devices, sodium‐ion batteries (SIBs) with abundant reserve, low cost, and similar electrochemical properties have the potential to partly replace the commercial lithium‐ion batteries. In this study, a facile metal‐organic framework (MOF)‐derived selenidation strategy to synthesize in situ carbon‐encapsulated selenides as superior anode for SIBs is rationally designed. These selenides with particular micro‐ and nanostructured features deliver ultrastable cycling performance at high charge–discharge rate and demonstrate ultraexcellent rate capability. For example, the uniform peapod‐like Fe7Se8@C nanorods represent a high specific capacity of 218 mAh g?1 after 500 cycles at 3 A g?1 and the porous NiSe@C spheres display a high specific capacity of 160 mAh g?1 after 2000 cycles at 3 A g?1. The current simple MOF‐derived method could be a promising strategy for boosting the development of new functional inorganic materials for energy storage, catalysis, and sensors.  相似文献   

7.
GaN is demonstrated to be an ideal anode for Li‐ion batteries (LIBs) for the first time. Amorphous GaN@Cu nanorods (a‐GaN@Cu) freestanding electrode is designed via a low‐temperature pulsed laser deposition method, which exhibits prominent rate capability and untralong lifespan as an anode for LIBs. With porous interconnected metal nanorods substrate to improve the structure integrity and electronic conductivity, the a‐GaN@Cu electrode delivers a capacity recovery of 980 mAh g?1 after 150 cycles from 0.25 to 6.25 A g?1 and a high discharge capacity of 509 mAh g?1 after 3000 cycles at 10.0 A g?1. The lithium storage in the a‐GaN is also systematically studied, which suggests a redox reaction mechanism.  相似文献   

8.
Chloride ion batteries (CIBs) are regarded as promising energy storage systems due to their large theoretical volumetric energy density, high abundance, and low cost of chloride resources. Herein, the synthesis of CoFe layered double hydroxide in the chloride form (CoFe–Cl LDH), for use as a new cathode material for CIBs, is demonstrated for the first time. The CoFe–Cl LDH exhibits a maximum capacity of 239.3 mAh g?1 and a high reversible capacity of ≈160 mAh g?1 over 100 cycles. The superb Cl? ion storage of CoFe–Cl LDH is attributed to its unique topochemical transformation property during the charge/discharge process: a reversible intercalation/deintercalation of Cl? ions in cathode with slight expansion/contraction of basal spacing, accompanied by chemical state changes in Co2+/Co3+ and Fe2+/Fe3+ couples. First‐principles calculations reveal that CoFe–Cl LDH is an excellent Cl? ion conductor, with extremely low energy barriers (0.12?0.25 eV) for Cl? diffusion. This work opens a new avenue for LDH materials as promising cathodes for anion‐type rechargeable batteries, which are regarded as formidable competitors to traditional metal ion‐shuttling batteries.  相似文献   

9.
Graphene scroll is an emerging 1D tubular form of graphitic carbon that has potential applications in electrochemical energy storage. However, it still remains a challenge to composite graphene scrolls with other nanomaterials for building advanced electrode configuration with fast and durable lithium storage properties. Here, a transition‐metal‐oxide‐based hierarchically ordered 3D porous electrode is designed based on assembling 1D core–sheath MnO@N‐doped graphene scrolls with 2D N‐doped graphene ribbons. In the resulting architecture, porous MnO nanowires confined in tubular graphene scrolls are mechanically isolated but electronically well‐connected, while the interwoven graphene ribbons offer continuous conductive paths for electron transfer in all directions. Moreover, the elastic graphene scrolls together with enough internal voids are able to accommodate the volume expansion of the enclosed MnO. Because of these merits, the as‐built electrode manifests ultrahigh rate capability (349 mAh g?1 at 8.0 A g?1; 205 mAh g?1 at 15.0 A g?1) and robust cycling stability (812 mAh g?1 remaining after 1000 cycles at 2.0 A g?1) and is the most efficient MnO‐based anode ever reported for lithium‐ion batteries. This unique multidimensional and hierarchically ordered structure design is believed to hold great potential in generalizable synthesis of graphene scrolls composited with oxide nanowires for mutifuctional energy storage.  相似文献   

10.
Hollow structures are often used to relieve the intrinsic strain on metal oxide electrodes in alkali‐ion batteries. Nevertheless, one common drawback is that the large interior space leads to low volumetric energy density and inferior electric conductivity. Here, the von Mises stress distribution on a mesoporous hollow bowl (HB) is simulated via the finite element method, and the vital role of the porous HB structure on strain‐relaxation behavior is confirmed. Then, N‐doped‐C coated mesoporous α‐Fe2O3 HBs are designed and synthesized using a multistep soft/hard‐templating strategy. The material has several advantages: (i) there is space to accommodate strains without sacrificing volumetric energy density, unlike with hollow spheres; (ii) the mesoporous hollow structure shortens ion diffusion lengths and allows for high‐rate induced lithiation reactivation; and (iii) the N‐doped carbon nanolayer can enhance conductivity. As an anode in lithium‐ion batteries, the material exhibits a very high reversible capacity of 1452 mAh g?1 at 0.1 A g?1, excellent cycling stability of 1600 cycles (964 mAh g?1 at 2 A g?1), and outstanding rate performance (609 mAh g?1 at 8 A g?1). Notably, the volumetric specific capacity of composite electrode is 42% greater than that of hollow spheres. When used in potassium‐ion batteries, the material also shows high capacity and cycle stability.  相似文献   

11.
Bismuth (Bi) is an attractive material as anodes for both sodium‐ion batteries (NIBs) and potassium‐ion batteries (KIBs), because it has a high theoretical gravimetric capacity (386 mAh g?1) and high volumetric capacity (3800 mAh L?1). The main challenges associated with Bi anodes are structural degradation and instability of the solid electrolyte interphase (SEI) resulting from the huge volume change during charge/discharge. Here, a multicore–shell structured Bi@N‐doped carbon (Bi@N‐C) anode is designed that addresses these issues. The nanosized Bi spheres are encapsulated by a conductive porous N‐doped carbon shell that not only prevents the volume expansion during charge/discharge but also constructs a stable SEI during cycling. The Bi@N‐C exhibits unprecedented rate capability and long cycle life for both NIBs (235 mAh g?1 after 2000 cycles at 10 A g?1) and KIBs (152 mAh g?1 at 100 A g?1). The kinetic analysis reveals the outstanding electrochemical performance can be attributed to significant pseudocapacitance behavior upon cycling.  相似文献   

12.
To tackle the issue of inferior cycle stability and rate capability for MnO anode materials in lithium ion batteries, a facile strategy is explored to prepare a hybrid material consisting of MnO nanocrystals grown on conductive graphene nanosheets. The prepared MnO/graphene hybrid anode exhibits a reversible capacity as high as 2014.1 mAh g?1 after 150 discharge/charge cycles at 200 mA g?1, excellent rate capability (625.8 mAh g?1 at 3000 mA g?1), and superior cyclability (843.3 mAh g?1 even after 400 discharge/charge cycles at 2000 mA g?1 with only 0.01% capacity loss per cycle). The results suggest that the reconstruction of the MnO/graphene electrodes is intrinsic due to conversion reactions. A long‐term stable nanoarchitecture of graphene‐supported ultrafine manganese oxide nanoparticles is formed upon cycling, which yields a long‐life anode material for lithium ion batteries. The lithiation and delithiation behavior suggests that the further oxidation of Mn(II ) to Mn(IV ) and the interfacial lithium storage upon cycling contribute to the enhanced specific capacity. The excellent rate capability benefits from the presence of conductive graphene and a short transportation length for both lithium ions and electrons. Moreover, the as‐formed hybrid nanostructure of MnO on graphene may help achieve faster kinetics of conversion reactions.  相似文献   

13.
Rechargeable aqueous Zn‐based batteries show great potential for energy storage systems due to their good reliability, low cost, environmental friendliness, etc. However, the capacity of the most studied Mn‐, V‐, and Prussian blue analog‐based Zn‐ion batteries (the type with Zn2+ insertion) and the other type Zn‐based batteries without Zn2+ insertion (such as metal Ag and Ni or Co oxides/hydroxides) does not exceed 400 mAh g?1. Cu is a promising cathode with a high theoretical capacity of 844 mAh g?1 based on its unique two‐electron transfer process (Cu0 ? Cu2+), but Cu–Zn batteries have been impractical to recharge since they was invented by Daniell in 1836. By adjusting the solubility of Cu2+ in an alkaline solution, a rechargeable high‐performance Cu–Zn battery is achieved. A high specific capacity of 718 mAh g?1 is obtained for the prepared Cu clusters. Moreover, commercial Cu foil is explored for direct use as the cathode material and shows high capacity and stability through a simple self‐activation process. This rechargeable Cu–Zn battery is attractive for application due to its high capacity, simple synthesis method, environmental friendliness, and low cost.  相似文献   

14.
All‐solid‐state lithium metal batteries (ASSLMBs) have attracted significant attention due to their superior safety and high energy density. However, little success has been made in adopting Li metal anodes in sulfide electrolyte (SE)‐based ASSLMBs. The main challenges are the remarkable interfacial reactions and Li dendrite formation between Li metal and SEs. In this work, a solid‐state plastic crystal electrolyte (PCE) is engineered as an interlayer in SE‐based ASSLMBs. It is demonstrated that the PCE interlayer can prevent the interfacial reactions and lithium dendrite formation between SEs and Li metal. As a result, ASSLMBs with LiFePO4 exhibit a high initial capacity of 148 mAh g?1 at 0.1 C and 131 mAh g?1 at 0.5 C (1 C = 170 mA g?1), which remains at 122 mAh g?1 after 120 cycles at 0.5 C. All‐solid‐state Li‐S batteries based on the polyacrylonitrile‐sulfur composite are also demonstrated, showing an initial capacity of 1682 mAh g?1. The second discharge capacity of 890 mAh g?1 keeps at 775 mAh g?1 after 100 cycles. This work provides a new avenue to address the interfacial challenges between Li metal and SEs, enabling the successful adoption of Li metal in SE‐based ASSLMBs with high energy density.  相似文献   

15.
As an anode material for lithium‐ion batteries, titanium dioxide (TiO2) shows good gravimetric performance (336 mAh g?1 for LiTiO2) and excellent cyclability. To address the poor rate behavior, slow lithium‐ion (Li+) diffusion, and high irreversible capacity decay, TiO2 nanomaterials with tuned phase compositions and morphologies are being investigated. Here, a promising material is prepared that comprises a mesoporous “yolk–shell” spherical morphology in which the core is anatase TiO2 and the shell is TiO2(B). The preparation employs a NaCl‐assisted solvothermal process and the electrochemical results indicate that the mesoporous yolk–shell microspheres have high specific reversible capacity at moderate current (330.0 mAh g?1 at C/5), excellent rate performance (181.8 mAh g?1 at 40C), and impressive cyclability (98% capacity retention after 500 cycles). The superior properties are attributed to the TiO2(B) nanosheet shell, which provides additional active area to stabilize the pseudocapacity. In addition, the open mesoporous morphology improves diffusion of electrolyte throughout the electrode, thereby contributing directly to greatly improved rate capacity.  相似文献   

16.
Seeking high‐capacity, high‐rate, and durable anode materials for lithium‐ion batteries (LIBs) has been a crucial aspect to promote the use of electric vehicles and other portable electronics. Here, a novel alloy‐forming approach to convert amorphous Si (a‐Si)‐coated copper oxide (CuO) core–shell nanowires (NWs) into hollow and highly interconnected Si–Cu alloy (mixture) nanotubes is reported. Upon a simple H2 annealing, the CuO cores are reduced and diffused out to alloy with the a‐Si shell, producing highly interconnected hollow Si–Cu alloy nanotubes, which can serve as high‐capacity and self‐conductive anode structures with robust mechanical support. A high specific capacity of 1010 mAh g?1 (or 780 mAh g?1) has been achieved after 1000 cycles at 3.4 A g?1 (or 20 A g?1), with a capacity retention rate of ≈84% (≈88%), without the use of any binder or conductive agent. Remarkably, they can survive an extremely fast charging rate at 70 A g?1 for 35 runs (corresponding to one full cycle in 30 s) and recover 88% capacity. This novel alloy‐nanotube structure could represent an ideal candidate to fulfill the true potential of Si‐loaded LIB applications.  相似文献   

17.
High capacity cathode materials for long‐life rechargeable lithium batteries are urgently needed. Selenium cathode has recently attracted great research attention due to its comparable volumetric capacity to but much better electrical conductivity than widely studied sulfur cathode. However, selenium cathode faces similar issues as sulfur (i.e., shuttling of polyselenides, volumetric expansion) and high performance lithium‐selenium batteries (Li–Se) have not yet been demonstrated at selenium loading >60% in the electrode. In this work, a 3D mesoporous carbon nanoparticles and graphene hierarchical architecture to storage selenium as binder‐free cathode material (Se/MCN‐RGO) for high energy and long life Li–Se batteries is presented. Such architecture not only provides the electrode with excellent electrical and ionic conductivity, but also efficiently suppresses polyselenides shuttling and accommodates volume change during charge/discharge. At selenium content of 62% in the entire cathode, the free‐standing Se/MCN‐RGO exhibits high discharge capacity of 655 mAh g?1 at 0.1 C (97% of theoretical capacity) and long cycling stability with a very small capacity decay of 0.008% per cycle over 1300 cycles at 1 C. The present report demonstrates significant progress in the development of high capacity cathode materials for long‐life Li batteries and flexible energy storage device.  相似文献   

18.
The dramatically increasing demand of high‐energy lithium‐ion batteries (LIBs) urgently requires advanced substitution for graphite‐based anodes. Herein, inspired from the extra capacity of lithium storage in solid‐electrolyte interface (SEI) films, layered hydroxide cobalt acetates (LHCA, Co(Ac)0.48(OH)1.52·0.55H2O) are introduced as novel and high‐efficiency anode materials. Furthermore, ultrathin LHCA nanoplates are face‐to‐face anchored on the surface of graphene nanosheets (GNS) through a facile solvothermal method to improve the electronic transport and avoid agglomeration during repeated cycles. Profiting from the parallel structure, LHCA//GNS nanosheets exhibit extraordinary long‐term and high‐rate performance. At the current densities of 1000 and 4000 mA g?1, the reversible capacities maintain ≈1050 mAh g?1 after 200 cycles and ≈780 mAh g?1 after 300 cycles, respectively, much higher than the theoretical value of LHCA according to the conversion mechanism. Fourier transform infrared spectroscopy confirms the conversion from acetate to acetaldehyde after lithiation. A reasonable mechanism is proposed to elucidate the lithium storage behaviors referring to the electrocatalytic conversion of OH groups with Co nanocatalysts. This work can help further understand the contribution of SEI components (especially LiOH and LiAc) to lithium storage. It is envisaged that layered transition metal hydroxides can be used as advanced materials for energy storage devices.  相似文献   

19.
Graphdiyne (GDY), an emerging type of carbon allotropes, possesses fascinating electrical, chemical, and mechanical properties to readily spark energy applications in the realm of Li‐ion and Na‐ion batteries. Nevertheless, rational design of GDY architectures targeting advanced K‐ion storage has rarely been reported to date. Herein, the first example of synthesizing GDY frameworks in a scalable fashion to realize superb potassium storage for high‐performance K‐ion battery (KIB) anodes is showcased. To begin with, first principles calculations provide theoretical guidances for analyzing the intrinsic potassium storage capability of GDY. Meanwhile, the specific capacity is predicted to be as high as 620 mAh g?1, which is considerably augmented as compared with graphite (278 mAh g?1). Experimental tests then reveal that prepared GDY framework indeed harvests excellent electrochemical performance as a KIB anode, achieving high specific capacity (≈505 mAh g?1 at 50 mA g?1), outstanding rate performance (150 mAh g?1 at 5000 mA g?1) and favorable cycling stability (a high capacity retention of over 90% after 2000 cycles at 1000 mA g?1). Furthermore, kinetic analysis reveals that capacitive effect mainly accounts for the K‐ion storage, with operando Raman spectroscopy/ex situ X‐ray photoelectron spectroscopy identifying good electrochemical reversibility of GDY.  相似文献   

20.
Morphology reshaping or reconfiguration, a concept widely used in plastic surgery, energy harvesting, and reconfigurable robots, is introduced for the first time to construct densified electrodes and realize compact Li‐ion storage desirable for high specific energy storage field. Hausmannite‐based hybrid materials, as a proof‐of‐concept prototype, engineered by 1‐methyl‐2‐pyrrolidinone‐soluble surface/interface organic encapsulation, which is crucial in reshaping, exhibit a remarkable increase in the volumetric capacity of more than five times after this process (≈1889 Ah L?1 vs ≈322 Ah L?1). With the simultaneous maintenance of the intrinsic nature, good contact, and no collapsed/agglomerated unit structures of the materials in electrodes, the design affords a maximal increase in the packing compactness and manifests no sacrifice of the reversible ion storage capability (1150 mAh g?1 at 40 mA g?1), stable cycling (≈100% capacity retention), high rate performance (185 mAh g?1 at 10 A g?1), and long lifespan (1000 cycles with 108% capacity retention, ≈455 mAh g?1 at 3 A g?1) for relatively highly loaded electrodes (active materials: 1.20–5.34 mg cm?2). The concept may not only shed new light on fabricating advanced Si‐based and other high capacity–related densified Li storage electrodes but also inject fresh vitality into the field of high‐density power sources.  相似文献   

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