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1.
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   

2.
Sodium ion batteries (SIBs) are a promising alternative to lithium ion batteries for a broader range of energy storage applications in the future. However, the development of high‐performance anode materials is a bottleneck of SIBs advancement. In this work, Sb2Se3 nanorods uniformly wrapped by reduced graphene oxide (rGO) as a promising anode material for SIBs are reported. The results show that such Sb2Se3/rGO hybrid anode yields a high reversible mass‐specific energy capacity of 682, 448, and 386 mAh g?1 at a rate of 0.1, 1.0, and 2.0 A g?1, respectively, and sustains at least 500 stable cycles at a rate of 1.0 A g?1 with an average mass‐specific energy capacity of 417 mAh g?1 and capacity retention of 90.2%. In situ X‐ray diffraction study on a live SIB cell reveals that the observed high performance is a result of the combined Na+ intercalation, conversion reaction between Na+ and Se, and alloying reaction between Na+ and Sb. The presence of rGO also plays a key role in achieving high rate capacity and cycle stability by providing good electrical conductivity, tolerant accommodation to volume change, and strong electron interactions to the base Sb2Se3 anode.  相似文献   

3.
Hybrid metal–organic frameworks (MOFs) demonstrate great promise as ideal electrode materials for energy‐related applications. Herein, a well‐organized interleaved composite of graphene‐like nanosheets embedded with MnO2 nanoparticles (MnO2@C‐NS) using a manganese‐based MOF and employed as a promising anode material for Li‐ion hybrid capacitor (LIHC) is engineered. This unique hybrid architecture shows intriguing electrochemical properties including high reversible specific capacity 1054 mAh g?1 (close to the theoretical capacity of MnO2, 1232 mAh g?1) at 0.1 A g?1 with remarkable rate capability and cyclic stability (90% over 1000 cycles). Such a remarkable performance may be assigned to the hierarchical porous ultrathin carbon nanosheets and tightly attached MnO2 nanoparticles, which provide structural stability and low contact resistance during repetitive lithiation/delithiation processes. Moreover, a novel LIHC is assembled using a MnO2@C‐NS anode and MOF derived ultrathin nanoporous carbon nanosheets (derived from other potassium‐based MOFs) cathode materials. The LIHC full‐cell delivers an ultrahigh specific energy of 166 Wh kg?1 at 550 W kg?1 and maintained to 49.2 Wh kg?1 even at high specific power of 3.5 kW kg?1 as well as long cycling stability (91% over 5000 cycles). This work opens new opportunities for designing advanced MOF derived electrodes for next‐generation energy storage devices.  相似文献   

4.
This work studies for the first time the metallic 1T MoS2 sandwich grown on graphene tube as a freestanding intercalation anode for promising sodium‐ion batteries (SIBs). Sodium is earth‐abundant and readily accessible. Compared to lithium, the main challenge of sodium‐ion batteries is its sluggish ion diffusion kinetic. The freestanding, porous, hollow structure of the electrode allows maximum electrolyte accessibility to benefit the transportation of Na+ ions. Meanwhile, the metallic MoS2 provides excellent electron conductivity. The obtained 1T MoS2 electrode exhibits excellent electrochemical performance: a high reversible capacity of 313 mAh g?1 at a current density of 0.05 A g?1 after 200 cycles and a high rate capability of 175 mAh g?1 at 2 A g?1. The underlying mechanism of high rate performance of 1T MoS2 for SIBs is the high electrical conductivity and excellent ion accessibility. This study sheds light on using the 1T MoS2 as a novel anode for SIBs.  相似文献   

5.
Potassium‐ion batteries have been regarded as the potential alternatives to lithium‐ion batteries (LIBs) due to the low cost, earth abundance, and low potential of K (?2.936 vs standard hydrogen electrode (SHE)). However, the lack of low‐cost cathodes with high energy density and long cycle life always limits its application. In this work, high‐energy layered P2‐type hierarchical K0.65Fe0.5Mn0.5O2 (P2‐KFMO) microspheres, assembled by the primary nanoparticles, are fabricated via a modified solvent‐thermal method. Benefiting from the unique microspheres with primary nanoparticles, the K+ intercalation/deintercalation kinetics of P2‐KFMO is greatly enhanced with a stabilized cathodic electrolyte interphase on the cathode. The P2‐KFMO microsphere presents a highly reversible potassium storage capacity of 151 mAh g?1 at 20 mA g?1, fast rate capability of 103 mAh g?1 at 100 mA g?1, and long cycling stability with 78% capacity retention after 350 cycles. A full cell with P2‐KFMO microspheres as cathode and hard carbon as anode is constructed, which exhibits long‐term cycling stability (>80% of retention after 100 cycles). The present high‐performance P2‐KFMO microsphere cathode synthesized using earth‐abundant elements provides a new cost‐effective alternative to LIBs for large‐scale energy storage.  相似文献   

6.
Transition metal oxides, possessing high theoretical specific capacities, are promising anode materials for sodium‐ion batteries. However, the sluggish sodiation/desodiation kinetics and poor structural stability restrict their electrochemical performance. To achieve high and fast Na storage capability, in this work, rambutan‐like hybrid hollow spheres of carbon confined Co3O4 nanoparticles are synthesized by a facile one‐pot hydrothermal treatment with postannealing. The hierarchy hollow structure with ultrafine Co3O4 nanoparticles embedded in the continuous carbon matrix enables greatly enhanced structural stability and fast electrode kinetics. When tested in sodium‐ion batteries, the hollow structured composite electrode exhibits an outstandingly high reversible specific capacity of 712 mAh g?1 at a current density of 0.1 A g?1, and retains a capacity of 223 mAh g?1 even at a large current density of 5 A g?1. Besides the superior Na storage capability, good cycle performance is demonstrated for the composite electrode with 74.5% capacity retention after 500 cycles, suggesting promising application in advanced sodium‐ion batteries.  相似文献   

7.
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   

8.
Na‐ion Batteries have been considered as promising alternatives to Li‐ion batteries due to the natural abundance of sodium resources. Searching for high‐performance anode materials currently becomes a hot topic and also a great challenge for developing Na‐ion batteries. In this work, a novel hybrid anode is synthesized consisting of ultrafine, few‐layered SnS2 anchored on few‐layered reduced graphene oxide (rGO) by a facile solvothermal route. The SnS2/rGO hybrid exhibits a high capacity, ultralong cycle life, and superior rate capability. The hybrid can deliver a high charge capacity of 649 mAh g?1 at 100 mA g?1. At 800 mA g?1 (1.8 C), it can yield an initial charge capacity of 469 mAh g?1, which can be maintained at 89% and 61%, respectively, after 400 and 1000 cycles. The hybrid can also sustain a current density up to 12.8 A g?1 (≈28 C) where the charge process can be completed in only 1.3 min while still delivering a charge capacity of 337 mAh g?1. The fast and stable Na‐storage ability of SnS2/rGO makes it a promising anode for Na‐ion batteries.  相似文献   

9.
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   

10.
With the increasing demand for low cost, long lifetime, high energy density storage systems, an extensive amount of effort has recently been focused on the development of sodium‐ion batteries (SIBs), and a variety of cathode materials have been discovered. However, looking for the most suitable anode material for practical application is a major challenge for SIBs. Herein, a high capacity sulfur‐doped black phosphorus‐TiO2 (TiO2‐BP‐S) anode material for SIBs is first synthesized by a feasible and large‐scale high‐energy ball‐milling approach, and its stability in air exposure is investigated through X‐ray photoelectron spectroscopy. The morphology of TiO2‐BP‐S is characterized using transmission electron microscopy, indicating that the TiO2 nanoparticles produce P? Ti bonds with BP. The TiO2‐BP‐S composite with P? S and P? Ti bonds exhibits excellent stability in air and the superior electrochemical performance. For example, the discharge specific capacity is up to 490 mA h g?1 after 100 cycles at 50 mA g?1, and it remains at 290 mA h g?1 after 600 cycles at 500 mA g?1. Meanwhile, the scientific insight that the formation of stable P? S and P? Ti bonds can provide a guide for the practical large‐scale application of SIBs in other titanium base and black phosphorus materials is looked forward.  相似文献   

11.
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   

12.
Sodium‐ion batteries (SIBs) are regarded as the best alternative to lithium‐ion batteries due to their low cost and similar Na+ insertion chemistry. It is still challenging but greatly desired to design and develop novel electrode materials with high reversible capacity, long cycling life, and good rate capability toward high‐performance SIBs. This work demonstrates an innovative design strategy and a development of few‐layered molybdenum disulfide/sulfur‐doped graphene nanosheets (MoS2/SG) composites as the SIB anode material providing a high specific capacity of 587 mA h g?1 calculated based on the total composite mass and an extremely long cycling stability over 1000 cycles at a current density of 1.0 A g?1 with a high capacity retention of ≈85%. Systematic characterizations reveal that the outstanding performance is mainly attributed to the unique and robust composite architecture where few‐layered MoS2 and S‐doped graphene are intimately bridged at the hetero‐interface through a synergistic coupling effect via the covalently doped S atoms. The design strategy and mechanism understanding at the molecular level outlined here can be readily applied to other layered transition metal oxides for SIBs anode and play a key role in contributing to the development of high‐performance SIBs.  相似文献   

13.
Lithium ion battery is the predominant power source for portable electronic devices, electrical vehicles, and back‐up electricity storage units for clean and renewable energies. High‐capacity and long‐life electrode materials are essential for the next‐generation Li‐ion battery with high energy density. Here bimetal‐organic‐frameworks synthesis of Co0.4Zn0.19S@N and S codoped carbon dodecahedron is shown with rooted carbon nanotubes (Co‐Zn‐S@N‐S‐C‐CNT) for high‐performance Li‐ion battery application. Benefiting from the synergetic effect of two metal sulfide species for Li‐storage at different voltages, mesoporous dodecahedron structure, N and S codoped carbon overlayer and deep‐rooted CNTs network, the product exhibits a larger‐than‐theoretical reversible Li‐storage capacity of 941 mAh g?1 after 250 cycles at 100 mA g?1 and excellent high‐rate capability (734, 591, 505 mAh g?1 after 500 cycles at large current densities of 1, 2, and 5 A g?1 , respectively).  相似文献   

14.
Lithium ion batteries have attained great success in commercialization owing to their high energy density. However, the relatively delaying discharge/charge severely hinders their high power applications due to intrinsically diffusion‐controlled lithium storage of the electrode. This study demonstrates an ever‐increasing surface redox capacitive lithium storage originating from an unique microstructure evolution during cycling in a novel RGO–MnO–RGO sandwich nanostructure. Such surface pseudocapacitance is dynamically in equilibrium with diffusion‐controlled lithium storage, thereby achieving an unprecedented rate capability (331.9 mAh g?1 at 40 A g?1, 379 mAh g?1 after 4000 cycles at 15 A g?1) with outstanding cycle stability. The dynamic combination of surface and diffusion lithium storage of electrodes might open up possibilities for designing high‐power lithium ion batteries.  相似文献   

15.
Sodium‐ion batteries (SIBs) are considered as a promising alternative to lithium‐ion batteries, due to the abundant reserves and low price of Na sources. To date, the development of anode materials for SIBs is still confronted with many serious problems. In this work, encapsulation‐type structured MoSe2@hollow carbon nanosphere (HCNS) materials assembled with expanded (002) planes few‐layer MoSe2 nanosheets confined in HCNS are successfully synthesized through a facile strategy. Notably, the interlayer spacing of the (002) planes is expanded to 1.02 nm, which is larger than the intrinsic value of pristine MoSe2 (0.64 nm). Furthermore, the few‐layer nanosheets are space‐confined in the inner cavity of the HCNS, forming hybrid MoSe2@HCNS structures. When evaluated as anode materials for SIBs, it shows excellent rate capabilities, ultralong cycling life with exceptional Coulombic efficiency even at high current density, maintaining 501 and 471 mA h g?1 over 1000 cycles at 1 and 3 A g?1, respectively. Even when cycled at current densities as high as 10 A g?1, a capacity retention of 382 mA h g?1 can be achieved. The expanded (002) planes, 2D few‐layer nanosheets, and unique carbon shell structure are responsible for the ultralong cycling and high rate performance.  相似文献   

16.
Heterostructuring electrodes with multiple electroactive and inactive supporting components to simultaneously satisfy electrochemical and structural requirements has recently been identified as a viable pathway to achieve high‐capacity and durable sodium‐ion batteries (SIBs). Here, a new design of heterostructured SIB anode is reported consisting of double metal‐sulfide (SnCo)S2 nanocubes interlaced with 2D sulfur‐doped graphene (SG) nanosheets. The heterostructured (SnCo)S2/SG nanocubes exhibit an excellent rate capability (469 mAh g?1 at 10.0 A g?1) and durability (5000 cycles, 487 mAh g?1 at 5.0 A g?1, 92.6% capacity retention). In situ X‐ray diffraction reveals that the (SnCo)S2/SG anode undergoes a six‐stage Na+ storage mechanism of combined intercalation, conversion, and alloying reactions. The first‐principle density functional theory calculations suggest high concentration of p–n heterojunctions at SnS2/CoS2 interfaces responsible for the high rate performance, while in situ transmission electron microscopy unveils that the interlacing and elastic SG nanosheets play a key role in extending the cycle life.  相似文献   

17.
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   

18.
Metal–organic frameworks (MOFs) and relative structures with uniform micro/mesoporous structures have shown important applications in various fields. This paper reports the synthesis of unprecedented mesoporous NixCo3?xO4 nanorods with tuned composition from the Co/Ni bimetallic MOF precursor. The Co/Ni‐MOFs are prepared by a one‐step facile microwave‐assisted solvothermal method rather than surface metallic cation exchange on the preformed one‐metal MOF template, therefore displaying very uniform distribution of two species and high structural integrity. The obtained mesoporous Ni0.3Co2.7O4 nanorod delivers a larger‐than‐theoretical reversible capacity of 1410 mAh g?1 after 200 repetitive cycles at a small current of 100 mA g?1 with an excellent high‐rate capability for lithium‐ion batteries. Large reversible capacities of 812 and 656 mAh g?1 can also be retained after 500 cycles at large currents of 2 and 5 A g?1, respectively. These outstanding electrochemical performances of the ternary metal oxide have been mainly attributed to its interconnected nanoparticle‐integrated mesoporous nanorod structure and the synergistic effect of two active metal oxide components.  相似文献   

19.
Searching high capacity cathode materials is one of the most important fields of the research and development of sodium‐ion batteries (SIBs). Here, we report a FeO0.7F1.3/C nanocomposite synthesized via a solution process as a new cathode material for SIBs. This material exhibits a high initial discharge capacity of 496 mAh g?1 in a sodium cell at 50 °C. From the 3rd to 50th cycle, the capacity fading is only 0.14% per cycle (from 388 mAh g?1 at 3rd the cycle to 360 mAh g?1 at the 50th cycle), demonstrating superior cyclability. A high energy density of 650 Wh kg?1 is obtained at the material level. The reaction mechanism studies of FeO0.7F1.3/C with sodium show a hybridized mechanism of both intercalation and conversion reaction.  相似文献   

20.
Lithium‐ion batteries have undergone a remarkable development in the past 30 years. However, conventional electrodes are insufficient for the ever‐increasing demand of high‐energy batteries. Here, reported is a thick electrode with a dense structure, as an alternative to the commonly recognized porous framework. A low‐temperature sintering technology with the aid of aqueous solvent, high pressure, and an ion‐conductive additive is originally developed for preparing the LiCoO2 (LCO)/Li4Ti5O12 (LTO) dense‐structure electrode as the representative cathode/anode material. The 400 µm thick cathode with 110 mg cm?2 mass loading achieves a high specific capacity of 131.2 mAh g?1 with a good capacity retention of 96% over 150 cycles, far exceeding the commercial counterpart (≈40 µm) of 54.1 mAh g?1 with 39%. The ultrathick electrode of 1300 µm thickness presents a remarkable area capacity of 28.6 mAh cm?2 that is 16 times that of the commercial electrode. The full cell based on the dense electrodes delivers an extremely high areal capacity of 14.4 mAh cm?2. The ion‐diffusion coefficients of the densely sintered electrodes increase by nearly three orders of magnitude. This design opens up a new avenue for scalable and sustainable material manufacturing towards various practical applications.  相似文献   

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