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1.
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   

2.
2D electrode materials with layered structures have shown huge potential in the fields of lithium‐ and sodium‐ion batteries. However, their poor conductivity limits the rate performance and cycle stability of batteries. Herein a new colloid chemistry strategy is reported for making 2D ultrathin layered SnSe nanoplates (SnSe NPs) for achieving more efficient alkali‐ion batteries. Due to the effect of weak Van der Waals forces, each semiconductive SnSe nanoplate stacks on top of each other, which can facilitate the ion transfer and accommodate volume expansion during the charge and discharge process. This unique structure as well as the narrow‐bandgap semiconductor property of SnSe simultaneously meets the requirements of achieving fast ionic and electronic conductivities for alkali‐ion batteries. They exhibit high capacity of 463.6 mAh g−1 at 0.05 A g−1 for Na‐ion batteries and 787.9 mAh g−1 at 0.2 A g−1 for Li‐ion batteries over 300 cycles, and also high stability for alkali‐ion batteries.  相似文献   

3.
Hollow inorganic nanostructures have drawn great attention due to their fascinating features, such as large surface area, high loading capacity, and high permeability. The formation, characterization, and application of partially and entirely hollow structure by applying a Si‐based reactive ion deposition and etching method on silicon nanowire as a template are reported. This fabrication technique is extended to a stainless steel substrate to be used as the binder‐free anode for high capacity and high rate lithium‐ion batteries. The electrochemical analyses exhibit that in addition to the high initial discharge capacity of 4125 mAh g?1 at a rate of C/16, the best performing electrode shows discharge/charge capacity of as high as 3302.14/2832.1 mAh g?1, respectively, with an excellent charge capacity retention of 96.7% over 100 cycles at a rate density of 1 C. Even at a rate of 12 C, the as‐designed structure is still able to deliver an impressive 1553 mAh g?1, which probably is attributed to fast lithium diffusion in its hollow part and high porosity of Si and alumina layer. It is proved that the change in hollowness ratio significantly affects capacity retention and average coulombic efficiency of the lithium‐ion cells.  相似文献   

4.
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   

5.
Rechargeable aluminum‐ion batteries (AIBs) are considered as a new generation of large‐scale energy‐storage devices due to their attractive features of abundant aluminum source, high specific capacity, and high energy density. However, AIBs suffer from a lack of suitable cathode materials with desirable capacity and long‐term stability, which severely restricts the practical application of AIBs. Herein, a binder‐free and self‐standing cobalt sulfide encapsulated in carbon nanotubes is reported as a novel cathode material for AIBs. The resultant new electrode material exhibits not only high discharge capacity (315 mA h g−1 at 100 mA g−1) and enhanced rate performance (154 mA h g−1 at 1 A g−1), but also extraordinary cycling stability (maintains 87 mA h g−1 after 6000 cycles at 1 A g−1). The free‐standing feature of the electrode also effectively suppresses the side reactions and material disintegrations in AIBs. The new findings reported here highlight the possibility for designing high‐performance cathode materials for scalable and flexible AIBs.  相似文献   

6.
Despite of extremely high theoretical capacity of Si (3579 mAh g−1), Si anodes suffer from pulverization and delamination of the electrodes induced by large volume change during charge/discharge cycles. To address those issues, herein, self-healable and highly stretchable multifunctional binders, polydioxythiophene:polyacrylic acid:phytic acid (PEDOT:PAA: PA, PDPP) that provide Si anodes with self-healability and excellent structural integrity is designed. By utilizing the self-healing binder, Si anodes self-repair cracks and damages of Si anodes generated during cycling. For the first time, it is demonstrated that Si anodes autonomously self-heal artificially created cracks in electrolytes under practical battery operating conditions. Consequently, this self-healable Si anode can still deliver a reversible capacity of 2312 mAh g−1 after 100 cycles with remarkable initial Coulombic efficiency of 94%, which is superior to other reported Si anodes. Moreover, the self-healing binder possesses enhanced Li-ion diffusivity with additional electronic conductivity, providing excellent rate capability with a capacity of 2084 mAh g−1 at a very high C-rate of 5 C.  相似文献   

7.
High-capacity anode materials (e.g., Si) are highly needed for high energy density battery systems, but they usually suffer from low initial coulombic efficiency (CE), short cycle life, and low-rate capability caused by large volume changes during the charge and discharge process. Here, a novel dendrimer-based binder for boosting the electrochemical performance of Si anodes is developed. The polyamidoamine (PMM) dendrimer not only can be used as binder, but also can be utilized as a crosslinker to construct 3D polyacrylic acid (PAA)-PMM composite binder for high-performance Si microparticles anodes. Benefiting from maximum interface interaction, strong average peeling force, and high elastic recovery rate of PAA-PMM composite, the Si electrode based on PAA-PMM achieves a high specific capacity of 3590 mAh g−1 with an initial CE of 91.12%, long-term cycle stability with 69.80% retention over 200 cycles, and outstanding rate capability (1534.8 mAh g−1 at 3000 mA g−1). This work opens a new avenue to use dendrimer chemistry for the development of high-performance binders for high-capacity anode materials.  相似文献   

8.
A sulfur‐linked carbonyl‐based poly(2,5‐dihydroxyl‐1,4‐benzoquinonyl sulfide) (PDHBQS) compound is synthesized and used as cathode material for lithium‐ion batteries (LIBs). Flexible binder‐free composite cathode with single‐wall carbon nanotubes (PDHBQS–SWCNTs) is then fabricated through vacuum filtration method with SWCNTs. Electrochemical measurements show that PDHBQS–SWCNTs cathode can deliver a discharge capacity of 182 mA h g−1 (0.9 mA h cm−2) at a current rate of 50 mA g−1 and a potential window of 1.5 V–3.5 V. The cathode delivers a capacity of 75 mA h g−1 (0.47 mA h cm−2) at 5000 mA g−1, which confirms its good rate performance at high current density. PDHBQS–SWCNTs flexible cathode retains 89% of its initial capacity at 250 mA g−1 after 500 charge–discharge cycles. Furthermore, large‐area (28 cm2) flexible batteries based on PDHBQS–SWCNTs cathode and lithium foils anode are also assembled. The flexible battery shows good electrochemical activities with continuous bending, which retains 88% of its initial discharge capacity after 2000 bending cycles. The significant capacity, high rate performance, superior cyclic performance, and good flexibility make this material a promising candidate for a future application of flexible LIBs.  相似文献   

9.
Flexible power sources have shown great promise in next‐generation bendable, implantable, and wearable electronic systems. Here, flexible and binder‐free electrodes of Na3V2(PO4)3/reduced graphene oxide (NVP/rGO) and Sb/rGO nanocomposites for sodium‐ion batteries are reported. The Sb/rGO and NVP/rGO paper electrodes with high flexibility and tailorability can be easily fabricated. Sb and NVP nanoparticles are embedded homogenously in the interconnected framework of rGO nanosheets, which provides structurally stable hosts for Na‐ion intercalation and deintercalation. The NVP/rGO paper‐like cathode delivers a reversible capacity of 113 mAh g?1 at 100 mA g?1 and high capacity retention of ≈96.6% after 120 cycles. The Sb/rGO paper‐like anode gives a highly reversible capacity of 612 mAh g?1 at 100 mA g?1, an excellent rate capacity up to 30 C, and a good cycle performance. Moreover, the sodium‐ion full cell of NVP/rGO//Sb/rGO has been fabricated, delivering a highly reversible capacity of ≈400 mAh g?1 at a current density of 100 mA g?1 after 100 charge/discharge cycles. This work may provide promising electrode candidates for developing next‐generation energy‐storage devices with high capacity and long cycle life.  相似文献   

10.
In this work, we report the synthesis of an three‐dimensional (3D) cone‐shape CNT clusters (CCC) via chemical vapor deposition (CVD) with subsequent inductively coupled plasma (ICP) treatment. An innovative silicon decorated cone‐shape CNT clusters (SCCC) is prepared by simply depositing amorphous silicon onto CCC via magnetron sputtering. The seamless connection between silicon decorated CNT cones and graphene facilitates the charge transfer in the system and suggests a binder‐free technique of preparing lithium ion battery (LIB) anodes. Lithium ion batteries based on this novel 3D SCCC architecture demonstrates high reversible capacity of 1954 mAh g?1 and excellent cycling stability (>1200 mAh g?1 capacity with ≈100% coulombic efficiency after 230 cycles).  相似文献   

11.
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   

12.
Hierarchically well‐developed porous graphene nanofibers comprising N‐doped graphitic C (NGC)‐coated cobalt oxide hollow nanospheres are introduced as anodes for high‐rate Li‐ion batteries. For this, three strategies, comprising the Kirkendall effect, metal–organic frameworks, and compositing with highly conductive C, are applied to the 1D architecture. In particular, NGC layers are coated on cobalt oxide hollow nanospheres as a primary transport path of electrons followed by graphene‐nanonetwork‐constituting nanofibers as a continuous and secondary electron transport path. Superior cycling performance is achieved, as the unique nanostructure delivers a discharge capacity of 823 mAh g?1 after 500 cycles at 3.0 A g?1 with a low decay rate of 0.092% per cycle. The rate capability is also noteworthy as the structure exhibits high discharge capacities of 1035, 929, 847, 787, 747, 703, 672, 650, 625, 610, 570, 537, 475, 422, 294, and 222 mAh g?1 at current densities of 0.5, 1.5, 3, 5, 7, 10, 12, 15, 18, 20, 25, 30, 40, 50, 80, and 100 A g?1, respectively. In view of the highly efficient Li+ ion/electron diffusion and high structural stability, the present nanostructuring strategy has a huge potential in opening new frontiers for high‐rate and long‐lived stable energy storage systems.  相似文献   

13.
Potassium‐ion batteries (KIBs) are promising alternatives to lithium‐ion batteries because of the abundance and low cost of K. However, an important challenge faced by KIBs is the search for high‐capacity materials that can hold large‐diameter K ions. Herein, copper oxide (CuO) nanoplates are synthesized as high‐performance anode materials for KIBs. CuO nanoplates with a thickness of ≈20 nm afford a large electrode–electrolyte contact interface and short K+ ion diffusion distance. As a consequence, a reversible capacity of 342.5 mAh g?1 is delivered by the as‐prepared CuO nanoplate electrode at 0.2 A g?1. Even after 100 cycles at a high current density of 1.0 A g?1, the capacity of the electrode remains over 206 mAh g?1, which is among the best values for KIB anodes reported in the literature. Moreover, a conversion reaction occurs at the CuO anode. Cu nanoparticles form during the first potassiation process and reoxidize to Cu2O during the depotassiation process. Thereafter, the conversion reaction proceeds between the as‐formed Cu2O and Cu, yielding a reversible theoretical capacity of 374 mAh g?1. Considering their low cost, easy preparation, and environmental benignity, CuO nanoplates are promising KIB anode materials.  相似文献   

14.
Silicon (Si) has been considered a very promising anode material for lithium ion batteries due to its high theoretical capacity. However, high‐capacity Si nanoparticles usually suffer from low electronic conductivity, large volume change, and severe aggregation problems during lithiation and delithiation. In this paper, a unique nanostructured anode with Si nanoparticles bonded and wrapped by graphene is synthesized by a one‐step aerosol spraying of surface‐modified Si nanoparticles and graphene oxide suspension. The functional groups on the surface of Si nanoparticles (50–100 nm) not only react with graphene oxide and bind Si nanoparticles to the graphene oxide shell, but also prevent Si nanoparticles from aggregation, thus contributing to a uniform Si suspension. A homogeneous graphene‐encapsulated Si nanoparticle morphology forms during the aerosol spraying process. The open‐ended graphene shell with defects allows fast electrochemical lithiation/delithiation, and the void space inside the graphene shell accompanied by its strong mechanical strength can effectively accommodate the volume expansion of Si upon lithiation. The graphene shell provides good electronic conductivity for Si nanoparticles and prevents them from aggregating during charge/discharge cycles. The functionalized Si encapsulated by graphene sample exhibits a capacity of 2250 mAh g?1 (based on the total mass of graphene and Si) at 0.1C and 1000 mAh g?1 at 10C, and retains 85% of its initial capacity even after 120 charge/discharge cycles. The exceptional performance of graphene‐encapsulated Si anodes combined with the scalable and one‐step aerosol synthesis technique makes this material very promising for lithium ion batteries.  相似文献   

15.
Although silicon‐based materials are ideal candidate anodes for high energy density lithium‐ion batteries, the large volumetric expansion seriously damages the integrity of the electrodes and impedes commercial processes. Reasonable electrode design based on adjustable structures of silicon and strong binders prepared by a facile method is still a great challenge. Herein, a three‐pronged collaborative strategy via hollow nanocubes, amorphous Void@SiOx@C, and in situ cross‐linked polyacrylic acid and d ‐sorbitol 3D network binder (c‐PAA‐DS) is adopted to maintain structural/electrode integrality and stability. The all‐integrated c‐PAA‐DS/Void@SiOx@C electrode delivers excellent mechanical property, which is attributed to ductility of the c‐PAA‐DS binder and high adhesion energy between Void@SiOx@C and c‐PAA‐DS calculated by density functional theory. Benefiting from the synergistic effect of accommodation of the hollow structure, protection of outer carbon shell, amorphous Void@SiOx@C, and strong adhesive c‐PAA‐DS binder, c‐PAA‐DS/Void@SiOx@C shows excellent electrochemical performance. Long cycling stability with a reversible capacity of 696 mAh g?1 is obtained, as well as tiny capacity decay after 500 cycles at 0.5 A g?1 and high‐rate performance. The prelithiated Void@SiOx@C||LiNi0.5Co0.2Mn0.3O2 (NCM523) full cell is also assembled and shows a reversible capacity of 157 mAh g?1 at 0.5 C, delivering an excellent capacity retention of 94% after 160 cycles.  相似文献   

16.
Homogeneous ultrasmall T‐Nb2O5 nanocrystallites encapsulated in 1D carbon nanofibers (T‐Nb2O5/CNFs) are prepared through electrospinning followed by subsequent pyrolysis treatment. In a Na half‐cell configuration, the obtained T‐Nb2O5/CNFs with the merits of unique microstructures and inherent pseudocapacitance, deliver a stable capacity of 150 mAh g−1 at 1 A g−1 over 5000 cycles. Even at an ultrahigh charge–discharge rate of 8 A g−1, a high reversible capacity of 97 mAh g−1 is still achieved. By means of kinetic analysis, it is demonstrated that the larger ratio of surface Faradaic reactions of Nb2O5 at high rates is the major factor to achieve excellent rate performance. The prolonged cycle durability and excellent rate performance endows T‐Nb2O5/CNFs with potentials as anode materials for sodium‐ion batteries.  相似文献   

17.
Exploring flexible lithium‐ion batteries is required with the ever‐increasing demand for wearable and portable electronic devices. Selecting a flexible conductive substrate accompanying with closely coupled active materials is the key point. Here, a lightweight, flexible, and freestanding MXene/liquid metal paper is fabricated by confining 3 °C GaInSnZn liquid metal in the matrix of MXene paper without any binder or conductive additive. When used as anode for lithium‐ion cells, it can deliver a high discharge capacity of 638.79 mAh g?1 at 20 mA g?1. It also exhibits satisfactory rate capacities, with discharge capacities of 507.42, 483.33, 480.22, 452.30, and 404.47 mAh g?1 at 50, 100, 200, 500, and 1000 mA g?1, respectively. The cycling performance is obviously improved by slightly reducing the charge–discharge voltage range. The composite paper also has better electrochemical performance than liquid metal coated Cu foil. This study proposes a novel flexible anode by a clever combination of MXene paper and low‐melting point liquid metal, paving the way for next‐generation lithium‐ion batteries.  相似文献   

18.
With the fast development in flexible electronic technology, power supply devices with high performance, low‐cost, and flexibility are becoming more and more important. Potassium ion batteries (KIBs) have a brilliant prospect for applications benefiting from high voltage, lost cost, as well as similar electrochemistry to lithium ion batteries (LIBs). Although carbon materials have been studied as KIBs anodes, their rate capability and cycling stability are still unsatisfactory due to the large‐size potassium ions. Herein, a nitrogen (N) and phosphorus (P) dual‐doped vertical graphene (N, P‐VG) uniformly grown on carbon cloth (N, P‐VG@CC) is reported as a binder‐free anode for flexible KIBs. With the combined advantages of rich active sites, highly accessible surface, highly conductive network, larger interlayer spacing as well as robust structural stability, this binder‐free N, P‐VG@CC anode exhibits high capacity (344.3 mAh g?1), excellent rate capability (2000 mA g?1; 46.5% capacity retention), and prominent long‐term cycling stability (1000 cycles; 82% capacity retention), outperforming most of the recently reported carbonaceous anodes. Moreover, a potassium ion full cell is successfully assembled on the basis of potassium Prussian blue (KPB)//N, P‐VG@CC, exhibiting a large energy density of 232.5 Wh kg?1 and outstanding cycle stability.  相似文献   

19.
Carbonaceous materials have attracted immense interest as anode materials for Na‐ion batteries (NIBs) because of their good chemical, thermal stabilities, as well as high Na‐storage capacity. However, the carbonaceous materials as anodes for NIBs still suffer from the lower rate capability and poor cycle life. An N,O‐dual doped carbon (denoted as NOC) network is designed and synthesized, which is greatly favorable for sodium storage. It exhibits high specific capacity and ultralong cycling stability, delivering a capacity of 545 mAh g?1 at 100 mA g?1 after 100 cycles and retaining a capacity of 240 mAh g?1 at 2 A g?1 after 2000 cycles. The NOC composite with 3D well‐defined porosity and N,O‐dual doped induces active sites, contributing to the enhanced sodium storage. In addition, the NOC is synthesized through a facile solution process, which can be easily extended to the preparation of many other N,O‐dual doped carbonaceous materials for wide applications in catalysis, energy storage, and solar cells.  相似文献   

20.
The concept of an all‐integrated design with multifunctionalization is widely employed in optoelectronic devices, sensors, resonator systems, and microfluidic devices, resulting in benefits for many ongoing research projects. Here, maintaining structural/electrode stability against large volume change by means of an all‐integrated design is realized for silicon anodes. An all‐integrated silicon anode is achieved via multicomponent interlinking among carbon@void@silica@silicon (CVSS) nanospheres and cross‐linked carboxymethyl cellulose and citric acid polymer binder (c‐CMC‐CA). Due to the additional protection from the silica layer, CVSS is superior to the carbon@void@silicon (CVS) electrode in terms of long‐term cyclability. The as‐prepared all‐integrated CVSS electrode exhibits high mechanical strength, which can be ascribed to the high adhesivity and ductility of c‐CMC‐CA binder and the strong binding energy between CVSS and c‐CMC‐CA, as calculated based on density functional theory (DFT). This electrode exhibits a high reversible capacity of 1640 mA h g?1 after 100 cycles at a current density of 1 A g?1, high rate performance, and long‐term cycling stability with 84.6% capacity retention after 1000 cycles at 5 A g?1.  相似文献   

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