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1.
Hard carbon (HC) is the state‐of‐the‐art anode material for sodium‐ion batteries (SIBs). However, its performance has been plagued by the limited initial Coulombic efficiency (ICE) and mediocre rate performance. Here, experimental and theoretical studies are combined to demonstrate the application of lithium‐pretreated HC (LPHC) as high‐performance anode materials for SIBs by manipulating the solid electrolyte interphase in tetraglyme (TEGDME)‐based electrolyte. The LPHC in TEGDME can 1) deliver > 92% ICE and ≈220 mAh g?1 specific capacity, twice of the capacity (≈100 mAh g?1) in carbonate electrolyte; 2) achieve > 85% capacity retention over 1000 cycles at 1000 mA g?1 current density (4 C rate, 1 C = 250 mA g?1) with a specific capacity of ≈150 mAh g?1, ≈15 times of the capacity (10 mAh g?1) in carbonate. The full cell of Na3V2(PO4)3‐LPHC in TEGDME demonstrated close to theoretical specific capacity of ≈98 mAh g?1 based on Na3V2(PO4)3 cathode, ≈2.5 times of the value (≈40 mAh g?1) with nontreated HC. This work provides new perception on the anode development for SIBs.  相似文献   

2.
Metal phosphides are promising anode candidates for sodium‐ion batteries (SIBs) due to their high specific capacity and low operating potential but suffer from poor cycling stability caused by huge volume expansion and poor solid‐state ion transfer rate. Herein, a new strategy to grow a new class of mesoporous metal phosphide nanoarrays on carbon felt (CF) as binder‐free anodes for SIBs is reported. The resultant integrated electrodes demonstrate excellent cycling life up to 1000 times (>90% retention rate) and high rate capability of 535 mAh g?1 at a current density of 4 A g?1. Detailed characterization reveals that the synergistic effect of unique mesoporous structure for accommodating huge volume expansion during sodiation/desodiation process, ultrasmall primary particle size (≈10 nm) for providing larger electrode/electrolyte contact area and shorter ion diffusion distance, and 3D conductive networks for facilitating the electrochemical reaction, leads to the extraordinary battery performance. Remarkably, a full SIB using the new CoP4/CF anode and a Na3V2(PO4)2F3 cathode delivers an average operating voltage of ≈3.0 V, a reversible capacity of 553 mAh g?1, and very high energy density of ≈280 Wh kg?1 for SIBs. A flexible SIB with outstanding mechanical strength based on this binder‐free new anode is also demonstrated.  相似文献   

3.
Aqueous batteries, particularly those integrating organic active materials functioning in a neutral pH environment, stand out as highly promising contenders in the stationary electrochemical storage domain, owing to their unparalleled safety, sustainability, and low‐cost materials. Herein, a novel di‐block oligomer, serving as the negative electrode of an all‐organic aqueous battery, is shown to offer exceptional output capabilities. The battery's performance is further enhanced by a unique intermixed p/n‐type storage mechanism, which is able to simultaneously exchange light and naturally abundant Na+, Mg2+, and Cl?. Reaching up to 105 mAh g?1, this system shows remarkable capacity retention for several thousand cycles (6500 cycles, ≈40 days) in various neutral electrolytes, including raw ocean water (≈3000 cycles, ≈75 days). The surprisingly fast kinetics of this di‐block oligomer allow to attain an unmatched specific capacity of near to 60 mAh g?1electrode while entirely devoid of conducting additives, and more than 80 mAh g?1electrode with 10% carbon additive, as well as displaying an areal capacity as high as 3.4 mAh cm?2 at C rate. Full cell validation was demonstrated over 1600 cycles by virtue of a commercial 2,2,6,6‐tétraméthylpipéridin‐1‐yl)oxyl (TEMPO) molecule, which permitted an energy density of close to 40 Wh kg?1materials at C rate in a self‐pH‐buffered and inexpensive aqueous electrolyte.  相似文献   

4.
Antimony (Sb) is a promising anode material for sodium‐ion batteries owing to its large capacity of 660 mAh g?1. However, its practical application is restricted by the rapid capacity decay resulted from a large volume expansion up to 390% upon Na alloying. Herein, construction of a self‐supported Sb array that has enough space allowing for effective accommodation of the volume change is reported. The array of Sb prisms is directly grown on a Cu substrate via a template‐free electrodeposition, followed by mild heating to consolidate the structural integrity between Sb and Cu. The resulting 3D architecture endows the Sb array with excellent sodium storage performance, exhibiting a reversible capacity of 578 mAh g?1 and retaining 531 mAh g?1 over 100 cycles at 0.5 C. The potential of Sb array in sodium‐ion full cells by pairing it with a Na0.67(Ni0.23Mg0.1Mn0.67)O2 cathode is further demonstrated. This full cell affords a specific energy of 197 Wh kg?1 at 0.2 C and a specific power of 1280 W kg?1 at 5 C. Considering its low cost and scale‐up capability, the template‐free route may find extensive applications in designing electrode architectures.  相似文献   

5.
The synthesis of in situ polymer‐functionalized anatase TiO2 particles using an anchoring block copolymer with hydroxamate as coordinating species is reported, which yields nanoparticles (≈11 nm) in multigram scale. Thermal annealing converts the polymer brushes into a uniform and homogeneous carbon coating as proven by high resolution transmission electron microscopy and Raman spectroscopy. The strong impact of particle size as well as carbon coating on the electrochemical performance of anatase TiO2 is demonstrated. Downsizing the particles leads to higher reversible uptake/release of sodium cations per formula unit TiO2 (e.g., 0.72 eq. Na+ (11 nm) vs only 0.56 eq. Na+ (40 nm)) while the carbon coating improves rate performance. The combination of small particle size and homogeneous carbon coating allows for the excellent electrochemical performance of anatase TiO2 at high (134 mAh g?1 at 10 C (3.35 A g?1)) and low (≈227 mAh g?1 at 0.1 C) current rates, high cycling stability (full capacity retention between 2nd and 300th cycle at 1 C) and improved coulombic efficiency (≈99.8%).  相似文献   

6.
Developing multielectron reaction electrode materials is essential for achieving high specific capacity and high energy density in secondary batteries; however, it remains a great challenge. Herein, Na3MnTi(PO4)3/C hollow microspheres with an open and stable NASICON framework are synthesized by a spray‐drying‐assisted process. When applied as a cathode material for sodium‐ion batteries, the resultant Na3MnTi(PO4)3/C microspheres demonstrate fully reversible three‐electron redox reactions, corresponding to the Ti3+/4+ (≈2.1 V), Mn2+/3+ (≈3.5 V), and Mn3+/4+ (≈4.0 V vs Na+/Na) redox couples. In situ X‐ray diffraction results reveals that both solid‐solution and two‐phase electrochemical reactions are involved in the sodiation/desodiation processes. The high specific capacity (160 mAh g?1 at 0.2 C), outstanding cyclability (≈92% capacity retention after 500 cycles at 2 C), and the facile synthesis make the Na3MnTi(PO4)3/C a prospective cathode material for sodium‐ion batteries.  相似文献   

7.
A high‐rate of oxygen redox assisted by cobalt in layered sodium‐based compounds is achieved. The rationally designed Na0.6[Mg0.2Mn0.6Co0.2]O2 exhibits outstanding electrode performance, delivering a discharge capacity of 214 mAh g?1 (26 mA g?1) with capacity retention of 87% after 100 cycles. High rate performance is also achieved at 7C (1.82 A g?1) with a capacity of 107 mAh g?1. Surprisingly, the Na0.6[Mg0.2Mn0.6Co0.2]O2 compound is able to deliver capacity for 1000 cycles at 5C (at 1.3 A g?1), retaining 72% of its initial capacity of 108 mAh g?1. X‐ray absorption spectroscopy analysis of the O K‐edge indicates the oxygen‐redox species (O2?/1?) is active during cycling. First‐principles calculations show that the addition of Co reduces the bandgap energy from ≈2.65 to ≈0.61 eV and that overlapping of the Co 3d and O 2p orbitals facilitates facile electron transfer, enabling the long‐term reversibility of the oxygen redox, even at high rates. To the best of the authors' knowledge, this is the first report on high‐rate oxygen redox in sodium‐based cathode materials, and it is believed that the findings will open a new pathway for the use of oxygen‐redox‐based materials for sodium‐ion batteries.  相似文献   

8.
Na‐based batteries have long been regarded as an inexpensive, sustainable candidate for large‐scale stationary energy storage applications. Unfortunately, the market penetration of conventional Na‐NiCl2 batteries is approaching its limit for several reasons, including limited rate capability and high Ni cost. Herein, a Na‐FeCl2 battery operating at 190 °C is reported that allows a capacity output of 116 mAh g?1 at an extremely high current density of 33.3 mA cm?2 (≈0.6C). The superior rate performance is rooted in the intrinsically fast kinetics of the Fe/Fe2+ redox reaction. Furthermore, it is demonstrated that a small amount of Ni additive (10 mol%) effectively mitigates capacity fading of the Fe/NaCl cathode caused by Fe particle pulverization during long‐term cycling. The modified Fe/Ni cathode exhibits excellent cycling stability, maintaining a discharge energy density of over 295 Wh kg?1 for 200 cycles at 10 mA cm?2 (≈C/5).  相似文献   

9.
A Au nanoparticle‐coated Ni nanowire substrate without binder or carbon is used as the electrode (denoted as the Au/Ni electrode) for Li‐oxygen (Li‐O2) batteries. A minimal amount of Au nanoparticles with sizes of <30 nm on a Ni nanowire substrate are coated using a simple electrodeposition method to the extent that maximum capacity can be utilized. This optimized, one body, Au/Ni electrode shows high capacities of 921 mAh g?1Au, 591 mAh g?1Au, and 359 mAh g?1Au, which are obtained at currents of 300 mAg?1Au, 500 mAg?1Au, and 1000 mAg?1Au respectively. More importantly, the Au/Ni electrode exhibits excellent cycle stability over 200 cycles.  相似文献   

10.
All solid‐state sodium batteries (ASSBs) have attracted considerable attention due to their enhanced safety, long lifespan, and high energy density. However, several challenges have plagued the development of ASSBs, especially the relatively low ionic conductivity of solid‐state electrolytes (SSEs), large interfacial resistance, and low stability/compatibility between SSEs and electrodes. Here, a high‐performance all solid‐state sodium battery (NVP@C|PEGDMA‐NaFSI‐SPE|Na) is designed by employing carbon coated Na3V2(PO4)3 composite nanosheets (NVP@C) as the cathode, solvent‐free solid polymer electrolyte (PEGDMA‐NaFSI‐SPE) as the electrolyte and metallic sodium as the anode. The integrated electrolyte and cathode system prepared by the in situ polymerization process exhibits high ionic conductivity (≈10?4 S cm?1 at room temperature) and an outstanding electrolyte/electrode interface. Benefiting from these merits, the soft‐pack ASSB (NVP@C|PEGDMA‐NaFSI‐SPE|Na) delivers excellent cycling life over 740 cycles (capacity decay of only 0.007% per cycle) and maintains 95% of the initial reversible capacity with almost no self‐discharge even after resting for 3 months. Moreover, the bendable ASSB exhibits a high capacity of 106 mAh g?1 (corresponds to energy density of ≈355 Wh kg?1) at 0.5 C despite undergoing repeated bending for 535 cycles. This work offers a new strategy to fabricate high‐performance flexible ASSBs with a long lifespan and excellent flexibility.  相似文献   

11.
Titanium niobium oxide (TiNb2O7) has been recognized as a promising anode material for lithium‐ion batteries (LIBs) in view of its potential to operate at high rates with improved safety and high theoretical capacity of 387 mAh g?1. However, it suffers from poor Li+ ion diffusivity and low electronic conductivity originated from its wide band gap energy (Eg > 2 eV). Here, porous TiNb2O7 microspheres (PTNO MSs) are prepared via a facile solvothermal reaction. PTNO MSs have a particle size of ≈1.2 μm and controllable pore sizes in the range of 5–35 nm. Ammonia gas nitridation treatment is conducted on PTNO MSs to introduce conducting Ti1?xNbxN layer on the surface and form nitridated PTNO (NPTNO) MSs. The porous structure and conducting Ti1?xNbxN layer enhance the transport kinetics associated with Li+ ions and electrons, which leads to significant improvement in electrochemical performance. As a result, the NPTNO electrode shows a high discharge capacity of ≈265 mAh g?1, remarkable rate capability (≈143 mAh g?1 at 100 C) and durable long‐term cyclability (≈91% capacity retention over 1000 cycles at 5 C). These results demonstrate the great potential of TiNb2O7 as a practical high‐rate anode material for LIBs.  相似文献   

12.
Na3V2(PO4)3 has attracted great attention due to its high energy density and stable structure. However, in order to boost its application, the discharge potential of 3.3–3.4 V (vs Na+/Na) still needs to be improved and substitution of vanadium with other lower cost and earth‐abundant active redox elements is imperative. Therefore, the Na superionic conductor (NASICON)‐structured Na4MnV(PO4)3 seems to be more attractive due to its lower toxicity and higher voltage platform resulting from the partial substitution of V with Mn. However, Na4MnV(PO4)3 still suffers from poor electronic conductivity, leading to unsatisfactory capacity delivering and poor high‐rate capability. In this work, a graphene aerogel–supported in situ carbon–coated Na4MnV(PO4)3 material is synthesized through a feasible solution‐route method. The elaborately designed Na4MnV(PO4)3 can reach ≈380 Wh kg?1 at 0.5 C (1 C = 110 mAh g?1) and realize superior high‐rate capability evenat 50 C (60.1 mAh g?1) with a long cycle‐life of 4000 cycles at 20 C. This impressive progress should be ascribed to the multifunctional 3D carbon framework and the distinctive structure of trigonal Na4MnV(PO4)3, which are deeply investigated by both experiments and calculations.  相似文献   

13.
Delivery of high‐energy density with long cycle life is facing a severe challenge in developing cathode materials for rechargeable sodium‐ion batteries (SIBs). Here a composite Na0.6MnO2 with layered–tunnel structure combining intergrowth morphology of nanoplates and nanorods for SIBs, which is clearly confirmed by micro scanning electron microscopy, high‐resolution transmission electron microscopy as well as scanning transmission electron microscopy with atomic resolution is presented. Owing to the integrated advantages of P2 layered structure with high capacity and that of the tunnel structure with excellent cycling stability and superior rate performance, the composite electrode delivers a reversible discharge capacity of 198.2 mAh g?1 at 0.2C rate, leading to a high‐energy density of 520.4 Wh kg?1. This intergrowth integration engineering strategy may modulate the physical and chemical properties in oxide cathodes and provide new perspectives on the optimal design of high‐energy density and high‐stable materials for SIBs.  相似文献   

14.
The design and fabrication of high‐performance all‐plastic batteries is essentially important to achieve future flexible electronics. A major challenge in this field is the lack of stable and reliable soft organic electrodes with satisfactory performance. Here, a novel all‐plastic‐electrode based Li‐ion battery with a single flexible bi‐functional ladderized heterocyclic poly(quinone), (C6O2S2)n, as both cathode and anode is demonstrated. Benefiting from its unique ladder‐like quinone and dithioether structure, the as‐prepared polymer cathode shows a high energy density of 624 Wh kg?1 (vs lithium anode) and a stable battery life of 1000 cycles. Moreover, the as‐fabricated symmetric full‐battery delivers a large capacity of 249 mAh g?1 (at 20 mA g?1), a good capacity retention of 119 mAh g?1 after 250 cycles (at 1.0 A g?1) and a noteworthy energy density up to 276 Wh kg?1. The superior performance of poly(2,3‐dithiino‐1,4‐benzoquinone)‐based electrode rivals most of the state‐of‐the‐art demonstrations on organic‐based metal‐ion shuttling batteries. The study provides an effective strategy to develop stable bi‐functional electrode materials toward the next‐generation of high performance all‐plastic batteries.  相似文献   

15.
Potassium‐ion hybrid capacitors (PIHCs), elaborately integrate the advantages of high output power as well as long lifespan of supercapacitors and the high energy density of batteries, and exhibit great possibilities for the future generations of energy storage devices. The critical next step for future implementation lies in exploring a high‐rate battery‐type anode with an ultra‐stable structure to match the capacitor‐type cathode. Herein, a “dual‐carbon” is constructed, in which a three‐dimensional nitrogen‐doped microporous carbon polyhedron (NMCP) derived from metal‐organic frameworks is tightly wrapped by two‐dimensional reduced graphene oxide (NMCP@rGO). Benefiting from the synergistic effect of the inner NMCP and outer rGO, the NMCP@rGO exhibits a superior K‐ion storage capability with a high reversible capacity of 386 mAh g?1 at 0.05 A g?1 and ultra‐long cycle stability with a capacity of 151.4 mAh g?1 after 6000 cycles at 5.0 A g?1. As expected, the as‐assembled PIHCs with a working voltage as high as 4.2 V present a high energy/power density (63.6 Wh kg?1 at 19 091 W kg?1) and excellent capacity retention of 84.7% after 12 000 cycles. This rational construction of advanced PIHCs with excellent performance opens a new avenue for further application and development.  相似文献   

16.
Li‐rich layered oxides (LLOs) can deliver almost double the capacity of conventional electrode materials such as LiCoO2 and LiMn2O4; however, voltage fade and capacity degradation are major obstacles to the practical implementation of LLOs in high‐energy lithium‐ion batteries. Herein, hexagonal La0.8Sr0.2MnO3?y (LSM) is used as a protective and phase‐compatible surface layer to stabilize the Li‐rich layered Li1.2Ni0.13Co0.13Mn0.54O2 (LM) cathode material. The LSM is Mn? O? M bonded at the LSM/LM interface and functions by preventing the migration of metal ions in the LM associated with capacity degradation as well as enhancing the electrical transfer and ionic conductivity at the interface. The LSM‐coated LM delivers an enhanced reversible capacity of 202 mAh g?1 at 1 C (260 mA g?1) with excellent cycling stability and rate capability (94% capacity retention after 200 cycles and 144 mAh g?1 at 5 C). This work demonstrates that interfacial bonding between coating and bulk material is a successful strategy for the modification of LLO electrodes for the next‐generation of high‐energy Li‐ion batteries.  相似文献   

17.
Potassium ion hybrid capacitors have great potential for large‐scale energy devices, because of the high power density and low cost. However, their practical applications are hindered by their low energy density, as well as electrolyte decomposition and collector corrosion at high potential in potassium bis(fluoro‐sulfonyl)imide‐based electrolyte. Therefore, anode materials with high capacity, a suitable voltage platform, and stability become a key factor. Here, N‐doping carbon‐coated FeSe2 clusters are demonstrated as the anode material for a hybrid capacitor, delivering a reversible capacity of 295 mAh g?1 at 100 mA g?1 over 100 cycles and a high rate capability of 158 mAh g?1 at 2000 mA g?1 over 2000 cycles. Meanwhile, through density functional theory calculations, in situ X‐ray diffraction, and ex situ transmission electron microscopy, the evolution of FeSe2 to Fe3Se4 for the electrochemical reaction mechanism is successfully revealed. The battery‐supercapacitor hybrid using commercial activated carbon as the cathode and FeSe2/N‐C as the anode is obtained. It delivers a high energy density of 230 Wh kg?1 and a power density of 920 W kg?1 (the energy density and power density are calculated based on the total mass of active materials in the anode and cathode).  相似文献   

18.
The symmetric batteries with an electrode material possessing dual cathodic and anodic properties are regarded as an ideal battery configuration because of their distinctive advantages over the asymmetric batteries in terms of fabrication process, cost, and safety concerns. However, the development of high‐performance symmetric batteries is highly challenging due to the limited availability of suitable symmetric electrode materials with such properties of highly reversible capacity. Herein, a triple‐hollow‐shell structured V2O5 (THS‐V2O5) symmetric electrode material with a reversible capacity of >400 mAh g?1 between 1.5 and 4.0 V and >600 mAh g?1 between 0.1 and 3.0 V, respectively, when used as the cathode and anode, is reported. The THS‐V2O5 electrodes assembled symmetric full lithium‐ion battery (LIB) exhibits a reversible capacity of ≈290 mAh g?1 between 2 and 4.0 V, the best performed symmetric energy storage systems reported to date. The unique triple‐shell structured electrode makes the symmetric LIB possessing very high initial coulombic efficiency (94.2%), outstanding cycling stability (with 94% capacity retained after 1000 cycles), and excellent rate performance (over 140 mAh g?1 at 1000 mA g?1). The demonstrated approach in this work leaps forward the symmetric LIB performance and paves a way to develop high‐performance symmetric battery electrode materials.  相似文献   

19.
A synthesis methodology is demonstrated to produce MoS2 nanoparticles with an expanded atomic lamellar structure that are ideal for Faradaic‐based capacitive charge storage. While much of the work on MoS2 focuses on the high capacity conversion reaction, that process is prone to poor reversibility. The pseudocapacitive intercalation‐based charge storage reaction of MoS2 is investigated, which is extremely fast and highly reversible. A major challenge in the field of pseudocapacitive‐based energy storage is the development of thick electrodes from nanostructured materials that can sustain the fast inherent kinetics of the active nanocrystalline material. Here a composite electrode comprised of a poly(acrylic acid) binder, carbon fibers, and carbon black additives is utilized. These electrodes deliver a specific capacity of 90 mAh g?1 in less than 20 s and can be cycled 3000 times while retaining over 80% of the original capacity. Quantitative kinetic analysis indicates that over 80% of the charge storage in these MoS2 nanocrystals is pseudocapacitive. Asymmetric full cell devices utilizing a MoS2 nanocrystal‐based electrode and an activated carbon electrode achieve a maximum power density of 5.3 kW kg?1 (with 6 Wh kg?1 energy density) and a maximum energy density of 37 Wh kg?1 (with 74 W kg?1power density).  相似文献   

20.
Olivine‐type LiMnPO4 (LMP) cathodes have gained enormous attraction for Li‐ion batteries (LIBs), thanks to their large theoretical capacity, high discharge platform, and thermal stability. However, it is still hugely challenging to achieve encouraging Li‐storage behaviors owing to their low electronic conductivity and limited lithium diffusion. Herein, the core double‐shell Ti‐doped LMP@NaTi2(PO4)3@C/3D graphene (TLMP@NTP@C/3D‐G) architecture is designed and constructed via an in situ synthetic methodology. A continuous electronic conducting network is formed with the unfolded 3D‐G and conducting carbon nanoshell. The Nasicon‐type NTP nanoshell with exceptional ionic conductivity efficiently inhibits gradual enrichment in by‐products, and renders low surfacial/interfacial electron/ion‐diffusion resistance. Besides, a rapid Li+ diffusion in the bulk structure is guaranteed with the reduction of MnLi+˙ antisite defects originating from the synchronous Ti‐doping. Benefiting from synergetic contributions from these design rationales, the integrated TLMP@NTP@C/3D‐G cathode yields high initial discharge capacity of ≈164.8 mAh g?1 at 0.05 C, high‐rate reversible capacity of ≈116.2 mAh g?1 at 10 C, and long‐term capacity retention of ≈93.3% after 600 cycles at 2 C. More significantly, the electrode design developed here will exert significant impact upon constructing other advanced cathodes for high‐energy/power LIBs.  相似文献   

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