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1.
    
Carbon-based materials have been considered as the most promising anode materials for both sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs), owing to their good chemical stability, high electrical conductivity, and environmental benignity. However, due to the large sizes of sodium and potassium ions, it is a great challenge to realize a carbon anode with high reversible capacity, long cycle life, and high rate capability. Herein, by rational design, N-doped 3D mesoporous carbon nanosheets (N-CNS) are successfully synthesized, which can realize unprecedented electrochemical performance for both SIBs and PIBs. The N-CNS possess an ultrathin nanosheet structure with hierarchical pores, ultrahigh level of pyridinic N/pyrrolic N, and an expanded interlayer distance. The beneficial features that can enhance the Na-/K-ion intercalation/deintercalation kinetic process, shorten the diffusion length for both ions and electrons, and accommodate the volume change are demonstrated. Hence, the N-CNS-based electrode delivers a high capacity of 239 mAh g−1 at 5 A g−1 after 10 000 cycles for SIBs and 321 mAh g−1 at 5 A g−1 after 5000 cycles for PIBs. First-principles calculation shows that the ultrahigh doping level of pyridinic N/pyrrolic N contributes to the enhanced sodium and potassium storage performance by modulating the charge density distribution on the carbon surface.  相似文献   

2.
    
Potassium-ion batteries (PIBs) have become one of the promising candidates for electrochemical energy storage that can provide low-cost and high-performance advantages. The poor cyclability and rate capability of PIBs are due to the intensive structural change of electrode materials during battery operation. Carbon-based materials as anodes have been successfully commercialized in lithium- and sodium-ion batteries but is still struggling in potassium-ion battery field. This work conducts structural engineering strategy to induce anionic defects within the carbon structures to boost the kinetics of PIBs anodes. The carbon framework provides a strong and stable structure to accommodate the volume variation of materials during cycling, and the further phosphorus doping modification is shown to enhance the rate capability. This is found due to the change of the pore size distribution, electronic structures, and hence charge storage mechanism. The optimized electrode in this work shows a high capacity of 175 mAh g−1 at a current density of 0.2 A g−1 and the enhancement of rate performance as the PIB anode (60% capacity retention with the current density increase of 50 times). This work, therefore provides a rational design for guiding future research on carbon-based anodes for PIBs.  相似文献   

3.
    
The rapid evolution of smart grid system urges researchers on exploiting systems with properties of high-energy, low-cost, and eco-friendly beyond lithium-ion batteries. Under the circumstances, sodium- and potassium-ion batteries with the semblable work mechanism to commercial lithium-ion batteries, hold the merits of cost-effective and earth-abundant. As a result, it is deemed a promising candidate for large-scale energy storage devices. Exploiting appropriate active electrode materials is in the center of the spotlight for the development of batteries. Metal selenides with special structures and relatively high theoretical capacity have aroused broad interest and achieved great achievements. To push the smooth development of metal selenides and enhancement of the electrochemical performance of sodium- and potassium-ion batteries, it is vital to grasp the inherent properties and electrochemical mechanisms of these materials. Herein, the state-of-the-art development and challenges of metal selenides are summarized and discussed. Meanwhile, the corresponding electrochemical mechanism and future development directions are also highlighted.  相似文献   

4.
    
Developing an anode with excellent rate performance, long-cycle stability, high coulombic efficiency, and high specific capacity is one of the key research directions of sodium-ion batteries. Among all the anode materials, noncrystalline carbon (NCC) has great possibilities according to its supreme performance and low cost, but with the complexity and variability of the structure. With the in-depth study of the sodium storage behaviors of NCC in recent years, three modes of interlayer intercalation, clustering into micropores, and adsorption are reported and summarized. Although the storage mechanism has gradually become more evident, the complex behavior of the ions at different voltage regions, especially in the low-voltage (plateau) region, still remains controversial. It is essential to understand further the relationship between ions and NCC structure during energy storage processes. Based on the summary of previous works, this article has reviewed the storage mechanism of sodium ions in NCC and evaluated the structure–behavior relationship between sodium-ion storage and the carbon structure.  相似文献   

5.
    
Constructing a porous structure is considered an appealing strategy to improve the electrochemical properties of carbon anodes for potassium-ion batteries (PIBs). Nevertheless, the correlation between electrochemical K-storage performance and pore structure has not been well elucidated, which hinders the development of high-performance carbon anodes. Herein, various porous carbons are synthesized with porosity structures ranging from micropores to micro/mesopores and mesopores, and systematic investigations are conducted to establish a relationship between pore characteristics and K-storage performance. It is found that micropores fail to afford accessible active sites for K ion storage, whereas mesopores can provide abundant surface adsorption sites, and the enlarged interlayer spacing facilitates the intercalation process, thus resulting in significantly improved K-storage performances. Consequently, PCa electrode with a prominent mesoporous structure achieves the highest reversible capacity of 421.7 mAh g−1 and an excellent rate capability of 191.8 mAh g−1 at 5 C. Furthermore, the assembled potassium-ion hybrid capacitor realizes an impressive energy density of 151.7 Wh kg−1 at a power density of 398 W kg−1. The proposed work not only deepens the understanding of potassium storage in carbon materials with distinctive porosities but also paves a path toward developing high-performance anodes for PIBs with customized energy storage capabilities.  相似文献   

6.
    
Three‐dimensional porous Sb/Sb2O3 anode materials are successfully fabricated using a simple electrodeposition method with a polypyrrole nanowire network. The Sb/Sb2O3–PPy electrode exhibits excellent cycle performance and outstanding rate capabilities; the charge capacity is sustained at 512.01 mAh g?1 over 100 cycles, and 56.7% of the charge capacity at a current density of 66 mA g?1 is retained at 3300 mA g?1. The improved electrochemical performance of the Sb/Sb2O3–PPy electrode is attributed not only to the use of a highly porous polypyrrole nanowire network as a substrate but also to the buffer effects of the Sb2O3 matrix on the volume expansion of Sb. Ex situ scanning electron microscopy observation confirms that the Sb/Sb2O3–PPy electrode sustains a strong bond between the nanodeposits and polypyrrole nanowires even after 100 cycles, which maintains good electrical contact of Sb/Sb2O3 with the current collector without loss of the active materials.  相似文献   

7.
    
Most reported carbonaceous anodes of potassium-ion batteries (PIBs) have limited capacities. One approach to improve the performance of carbon anodes is edge-nitrogen doping, which effectively enhances the K-ion adsorption energy. It remains challenging to achieve high edge-nitrogen doping due to the difficulty in controlling the nitrogen dopant configuration. Herein, a new synthesis strategy is proposed to prepare carbon anodes with ultrahigh edge-nitrogen doping for high-performance PIBs. Specifically, self-assembled supermolecule precursors derived from pyromellitic acid and melamine are directly pyrolyzed. During the pyrolysis process, the amidation and imidization reactions between pyromellitic acid and melamine before carbonization enable the successful carbonization of pyromellitic acid–melamine supermolecule. The obtained 3D nitrogen-doped turbostratic carbon (3D-NTC) possesses a 3D framework composed of carbon nanosheets, turbostratic crystalline structure, and an ultrahigh edge-nitrogen-doping level up to 16.8 at% (73.7% of total 22.8 at% nitrogen doping). These features endow 3D-NTCs with remarkable performances as PIB anodes. The 3D-NTC anode displays a high capacity of 473 mAh g−1, robust rate capability, and a long cycle life of 500 cycles with a high capacity retention of 93.1%. This new strategy will boost the development of carbon anodes for rechargeable alkali-metal-ion batteries.  相似文献   

8.
    
The microstructure of hard carbons (HCs) including interlayer distance and lateral ab direction and pore size distribution plays a key role in regulating the sodium ions storage performance. Herein, by employing the gelatinous agar as a model precursor, series P-doping HCs (P-HC-x, x = 1, 2, 3, 4) are facilely prepared in batches via controllably regulating its crosslinking state by phytic acid (PA) at a low carbonization temperature of 750 °C, in which PA plays three roles (acid, flame retardant, and P-doping precursor) in promoting the final structure of P-HC-x. Among those, the puparium like P-HC-2 with expanded carbon interlayer distance of 3.91 Å and shortened lateral ab direction of 9.4 nm delivers a high reversible capacity of 394 mAh g−1 at 0.1 A g−1 with high increased slope capacity of 363 mAh g−1 as well as an ultrafast charge-discharge feature and a superlong cycle life. Pairing with the Na3V2(PO4)3 cathode, the fabricated sodium-ion full cells exhibit the 132 mAh g−1 reversible capacity at 0.1 A g−1, and 86% capacity retention after 100 cycles. This work successfully develops slope-dominated high-performance carbon anode, which will provide new insights for the microstructure regulation and design of other precursor-derivedHCs.  相似文献   

9.
    
Sodium-ion batteries (SIBs) hold great promise owing to the naturally abundant sodium resource and high safety. The research focus of SIBs is usually directed toward electrode materials, while the binder as an important component is rarely investigated. Herein, a cross-linked sodium alginate (SA)/graphene oxide (GO) binder is judiciously designed to serve as a robust artificial interphase on the surface of both anode and cathode of SIBs. Benefiting from the cross-linking continuous network structure as well as the highly hydrophilic nature, the SA-GO binder possesses a large tensile strength of 197.7 Mpa and a high ionic conductivity of 0.136 mS cm−1, superior to pure SA (93.8 Mpa, 0.025 mS cm−1). Moreover, the structural design of SA-GO binder exhibits a strong binding ability to guarantee structural integrity during cycling. To demonstrate its effectiveness, polyanion-type phosphates (e.g., Na3(VO)2(PO4)2F) and chalcogenides (e.g., MoS2, VS2) are adopted as cathode and anode materials of SIBs, respectively. As compared to traditional binders (e.g., PVDF, SA), electrodes with the SA-GO binder exhibits significantly increased rate capability and cycling stability, such as Na3(VO)2(PO4)2F (40 C fast-charge, 84% capacity retention after 1000 cycles). This work highlights the role of novel aqueous-based binders in developing next-generation sodium-storage devices.  相似文献   

10.
    
The novel design of carbon materials with stable nanoarchitecture and optimized electrical properties featuring simultaneous intercalation of lithium ions (Li+) and sodium ions (Na+) is of great significance for the superb lithium–sodium storage capacities. Biomass-derived carbon materials with affluent porosity have been widely studied as anodes for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). However, it remains unexplored to further enhance the stability and utilization of the porous carbon skeleton during cycles. Here, a lotus stems derived porous carbon (LPC) with graphene quantum dots (GQDs) and intrinsic carbon nanowires framework (CNF) is successfully fabricated by a self-template method. The LPC anodes show remarkable Li+ and Na+ storage performance with ultrahigh capacity (738 mA h g−1 for LIBs and 460 mA h g−1 for SIBs at 0.2 C after 300 cycles, 1C≈372 mA h g−1) and excellent long-term stability. Structural analysis indicates that the CNFs-supported porous structure and internal GQDs with excellent electrical conductivity contribute significantly to the dominant capacitive storage mechanism in LPC. This work provides new perspectives for developing advanced carbon-based materials for multifunctional batteries with improved stability and utilization of porous carbon frameworks during cycles.  相似文献   

11.
    
Sodium-ion batteries (SIBs) have attracted tremendous attention as promising low-cost energy storage devices in future grid-scale energy management applications. Bismuth is a promising anode for SIBs due to its high theoretical capacity (386 mAh g−1). Nevertheless, the huge volume variation of Bi anode during (de)sodiation processes can cause the pulverization of Bi particulates and rupture of solid electrolyte interphase (SEI), resulting in quick capacity decay. It is demonstrated that rigid carbon framework and robust SEI are two essentials for stable Bi anodes. A lignin-derived carbonlayer wrapped tightly around the bismuth nanospheres provides a stable conductive pathway, while the delicate selection of linear and cyclic ether-based electrolytes enable robust and stable SEI films. These two merits enable the long-term cycling process of the LC-Bi anode. The LC-Bi composite delivers outstanding sodium-ion storage performance with an ultra-long cycle life of 10 000 cycles at a high current density of 5 A g−1 and an excellent rate capability of 94% capacity retention at an ultrahigh current density of 100 A g−1. Herein, the underlying origins of performance improvement of Bi anode are elucidated, which provides a rational design strategy for Bi anodes in practical SIBs.  相似文献   

12.
    
Engineering novel electrode materials with unique architectures has a significant impact on tuning the structural/electrochemical properties for boosting the performance of secondary battery systems. Herein, starting from well-organized WS2 nanorods, an ingenious design of a one-step method is proposed to prepare a bimetallic sulfide composite with a coaxial carbon coating layer, simply enabled by ZIF-8 introduction. Rich sulfur vacancies and WS2/ZnS heterojunctions can be simultaneously developed, that significantly improve ionic and electronic diffusion kinetics. In addition, a homogeneous carbon protective layer around the surface of the composite guarantees an outstanding structural stability, a reversible capacity of 170.8 mAh g−1 after 5000 cycles at a high rate of 5 A g−1. A great potential in practical application is also exhibited, where a full cell based on the WS2−x/ZnS@C anode and the P2-Na2/3Ni1/3Mn1/3O2 cathode can maintain a reversible capacity of 89.4 mAh g−1 after 500 cycles at 1 A g−1. Moreover, the underlying electrochemical Na storage mechanisms are illustrated in detail by theoretical calculations, electrochemical kinetic analysis, and operando X-ray diffraction characterization.  相似文献   

13.
    
Potassium-ion battery represents a promising alternative of conventional lithium-ion batteries in sustainable and grid-scale energy storage. Among various anode materials, elemental phosphorus (P) has been actively pursued owing to the ideal natural abundance, theoretical capacity, and electrode potential. However, the sluggish redox kinetics of elemental P has hindered fast and deep potassiation process toward the formation of final potassiation product (K3P), which leads to inferior reversible capacity and rate performance. Here, it is shown that rational design on black/red P heterostructure can significantly improve K-ion adsorption, injection and immigration, thus for the first time unlocking K3P as the reversible potassiation product for elemental P anodes. Density functional theory calculations reveal the fast adsorption and diffusion kinetics of K-ion at the heterostructure interface, which delivers a highly reversible specific capacity of 923 mAh g−1 at 0.05 A g−1, excellent rate capability (335 mAh g−1 at 1 A g−1), and cycling performance (83.3% capacity retention at 0.8 A g−1 after 300 cycles). These results can unlock other sluggish and irreversible battery chemistries toward sustainable and high-performing energy storage.  相似文献   

14.
    
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15.
    
Hard carbons (HCs) with high sloping capacity are considered as the leading candidate anode for sodium-ion batteries (SIBs); nevertheless, achieving basically complete slope-dominated behavior with high rate capability is still a big challenge. Herein, the synthesis of mesoporous carbon nanospheres with highly disordered graphitic domains and MoC nanodots modification via a surface stretching strategy is reported. The MoOx surface coordination layer inhibits the graphitization process at high temperature, thus creating short and wide graphite domains. Meanwhile, the in situ formed MoC nanodots can greatly promote the conductivity of highly disordered carbon. Consequently, MoC@MCNs exhibit an outstanding rate capacity (125 mAh g−1 at 50 A g−1). The “adsorption-filling” mechanism combined with excellent kinetics is also studied based on the short-range graphitic domains to reveal the enhanced slope-dominated capacity. The insight in this work encourages the design of HC anodes with dominated slope capacity toward high-performance SIBs.  相似文献   

16.
    
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17.
    
Prussian blue analogs (PBAs) show great promise as anode materials for potassium-ion batteries (PIBs) due to their high specific capacity. However, PBAs still suffer from the drawbacks of low electronic conductivity and poor structural stability, leading to inadequate rate and cyclic performance. To address these limitations, CoFe PBA nanocubes wrapped with N/S doped carbon network (CoFe PBA@NSC) as anode for PIBs is designed by using thermal-induced in situ conversion strategy. As expected, the structural advantages of nanosized PBA cubes, such as abundant interfaces and large surface area, enable the CoFe PBA@NSC electrode to demonstrate superior rate properties (557 and 131 mAh g−1 at 0.05 and 10 A g−1) and low capacity degradation (0.093% per cycle over 1000 cycles at 0.5 A g−1). Furthermore, several ex situ characterizations revealed the K-ion storage mechanism. Fe+ and Co0 are generated during potassicization, followed by a completely reversible chemical state of iron while some cobalt monomers remained during depotassication. Additionally, the as-built potassium-ion hybrid capacitor based on CoFe PBA@NSC anode exhibits a high energy density of 118 Wh kg−1. This work presents an alternative but promising synthesis route for Prussian blue analogs, which is significant for the advancement of PIBs and other related energy storage devices.  相似文献   

18.
    
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19.
    
Currently, the main obstacle to the widespread utilization of metal chalcogenides (MSx) as anode for potassium-ion batteries (PIBs) is their poor rate capability and inferior cycling stability as a result of the undesirable electrical conductivity and severe pulverization of the nanostructure during large K-ions intercalation-extraction processes. Herein, an ultrafast and long-life potassium storage of metal chalcogenide is rationally demonstrated by employing Fe0.4Ni0.6S solid-solution (FNS/C) through molecular structure engineering. Benefiting from improved electroactivity and intense interactions within the unique solid solution phase, the electrical conductivity and structure durability of Fe0.4Ni0.6S are vastly improved. As anticipated, the FNS/C electrode delivers superior rate properties (538.7 and 210.5 mAh g−1 at 0.1 and 10 A g−1, respectively) and long-term cycle stability (180.8 mAh g−1 at 5 A g−1 after 2000 cycles with a capacity decay of 0.011% per cycle). Moreover, the potassium storage mechanisms of Fe0.4Ni0.6S solid solution are comprehensively revealed by several in situ characterizations and theoretical calculations. This innovative molecular structure engineering strategy opens avenues to achieve high-quality metal chalcogenides for future advanced PIBs.  相似文献   

20.
    
Herein, the electrochemical properties and reaction mechanism of Li3‒2xCaxV2(PO4)3/C (x = 0, 0.5, 1, and 1.5) as negative electrode materials for sodium-ion/potassium-ion batteries (SIBs/PIBs) are investigated. All samples undergo a mixed contribution of diffusion-controlled and pseudocapacitive-type processes in SIBs and PIBs via Trasatti Differentiation Method, while the latter increases with Ca content increase. Among them, Li3V2(PO4)3/C exhibits the highest reversible capacity in SIBs and PIBs, while Ca1.5V2(PO4)3/C shows the best rate performance with a capacity retention of 46% at 20 C in SIBs and 47% at 10 C in PIBs. This study demonstrates that the specific capacity of this type of material in SIBs and PIBs does not increase with the Ca-content as previously observed in lithium-ion system, but the stability and performance at a high C-rate can be improved by replacing Li+ with Ca2+. This indicates that the insertion of different monovalent cations (Na+/K+) can strongly influence the redox reaction and structure evolution of the host materials, due to the larger ion size of Na+ and K+ and their different kinetic properties with respect to Li+. Furthermore, the working mechanism of both LVP/C and Ca1.5V2(PO4)3/C in SIBs are elucidated via in operando synchrotron diffraction and in operando X-ray absorption spectroscopy.  相似文献   

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