Sodiation Capacity Research Articles

Nano-crystalline Fe3V3O8 material as an efficient advanced anode for energy storage applications

The sodium-ion battery (SIB) is a rapidly developing electrochemically rechargeable storage device and a direct substitute for Li-ion batteries. Therefore, identifying novel materials for sodium-ion storage applications is important. Efficient electrodes are particularly desirable for enhancing storage performance in battery applications. In this study, we fabricated a novel Fe3V3O8 (FVO) anode material for Na/Li-ion storage using hydrothermal technology for the first time. The electrochemical results indicated that the initial sodiation capacity of the FVO anode is as high as 805 mA h g−1 at 100 mA g−1, and a reversible sodiation capacity of 540 mA h g−1 is maintained over 200 cycles at 500 mA g−1, which is more than 1.8 times the commercial hard carbon of ∼300 mA h g−1. In addition, the oxidation states of the chemical compound and the corresponding sodium reaction mechanism are predicted using X-ray absorption spectroscopy (XAS), X-ray photoelectron spectroscopy (XPS), and in-situ/ex-situ X-ray diffraction (XRD) analysis. Overall, the FVO material exhibited significantly higher electrochemical performance, demonstrating promising suitability for sodium-ion storage.

Unraveling the (De)sodiation Mechanisms of BiFeO3 at a High Rate with Operando XRD.

Development of new anode materials for Na-ion batteries strongly depends on a detailed understanding of their cycling mechanism. Due to instrumental limitations, the majority of mechanistic studies focus on operando materials' characterization at low cycling rates. In this work, we evaluate and compare the (de)sodiation mechanisms of BiFeO3 in Na-ion batteries at different current densities using operando X-ray diffraction (XRD) and ex situ X-ray absorption spectroscopy (XAS). BiFeO3 is a conversion-alloying anode material with a high initial sodiation capacity of ∼600 mAh g-1, when cycled at 0.1 A g-1. It does not change its performance or cycling mechanism, except for minor losses in capacity, when the current density is increased to 1 A g-1. In addition, operando XRD characterization carried out over multiple cycles shows that the Bi ⇋ NaBi (de)alloying reaction and the oxidation of Bi at the interface with the Na-Fe-O matrix are detrimental for cycling stability. The isolated NaBi ⇋ Na3Bi reaction is less damaging to the cycling stability of the material.

3D-engineered WO3 microspheres assembled by 2D nanosheets with superior sodium storage capacity.

Because of the inadequate sodium storage capacity of graphite, the exploration of high-performance SIB anodes is a crucial step forward. Herein, we report the hydrothermally synthesized self-assembled interconnected nanosheets of WO3 microspheres possessing admirable sodium storage in terms of cycling stability and acceptable rate capability. Benefitting from the interconnected nature of the nanosheets with a hollow interior, the WO3 microspheres exhibited a high sodiation capacity of 431 mA h g-1 at 100 mA g-1 and an excellent rate performance of 60 mA h g-1 at 500 mA g-1 with an impressive coulombic efficiency of around 99%. Importantly, even after continuous cycling with increasing current densities, a specific capacity as high as 220 mA h g-1 could be recovered at a current density of 50 mA g-1, suggesting excellent sodium storage reversibility.

Insights into the Sodiation Kinetics of Si and Ge Anodes for Sodium-Ion Batteries

Group IVA elements exhibit interesting Na storage capabilities due to the success of their Li alloy analogues. However, beyond hard carbon, they remain poorly understood as anodes for sodium-ion batteries (SIBs). Here, kinetic investigations of the electrochemical sodiation of Si and Ge are conducted using liquid electrolytes and half-cell configurations. Sodiation of Ge is found to be kinetically limited rather than thermodynamically limited. Either increasing temperature or decreasing sodiation rate can facilitate easier transformations from Ge to Na-Ge phases. A critical temperature seems to exist between 50 °C and 60 °C, beyond which a higher sodiation capacity is evident. The phase transformations are analyzed using Kolmogorov–Johnson–Mehl–Avrami theory. Following a one-dimensional growth, the Ge to NaGe4 is determined to be diffusion limited whereas NaGe4 to Na1+x Ge is controlled by reaction speed. Moreover, the Arrhenius equation is employed to investigate the temperature dependence on both phase transformations, giving activation energies of ∼50 kJ·mol−1 and ∼70 kJ·mol−1, respectively. Schematic models are proposed to elucidate the sodiation mechanisms, potentially influencing sought-after advancements in cell formats and classifications. Not only does this work lay the foundation for efforts on the Ge-based anodes, but also provides analogous kinetic information to Si/Sn-based ones for SIBs.

Revealing the electrolyte-enhancement effect of FeP/carbon nanosheets for superior sodium storage

Ether-based electrolytes are of exceptional benefit for forwarding conversion-type transition metal phosphides toward advanced sodium energy storage, but the rooted understanding of electrochemical enhancement is scarcely investigated. In this work, two-dimensional FeP-embedded carbon (FeP/C) hybrid nanosheets are rationally synthesized for probing the distinct sodium storage behaviors in different electrolytes. Compared to the ester-based counterpart, the ether-based electrolyte enables the FeP/C composite electrode to show a significant capacity increase from 363.5 to 516.6 mAh g−1 at 0.1 A g−1 over 150 cycling tests. Mechanistic analysis reveals that the particle refinement of FeP constantly generate extra active sites for more sodiation capacity. Additionally, it is identified that the electrode can be stabilized by forming a thin, uniform, and inorganic-rich solid electrolyte interface (SEI) layer induced by the ether-based electrolyte, retaining 94% of the initial capacity at 1 A g−1 after 800 cycles. This work can afford in-depth understanding and development of advanced conversion-type anode materials for sodium storage technologies.

Role of moderate strain engineering in Nickel Sulfide anode for advanced sodium-ion batteries

The lattice strain engineering of sodium storage materials is of great significance for developing reliable sodium-ion batteries (SIBs). Lattice strain engineering controls the structural evolution during sodium ion insertion/extraction and minimizes the aggregation of active material and volume expansion during cycling. Herein, the ball milling technique is used to tune the lattice strain of NiS nanocomposite, which was later employed as anode material in SIBs. The structurally tuned anode exhibits high sodiation capacity, good rate capability (495.7 mAh g−1 at 0.2 A g−1, 383.2 mAhg−1 at 15 Ag−1), and exceptional cycling performance (16,000 cycles at 5 A g−1). Significantly, introducing a considerable amount of moderate strain into the structure by the ball milling technique, researchers can solve the problem of structure instability, volume expansion, and high-capacity loss of the electrode materials during repeated cycling. Therefore, lattice strain engineering using ball milling is a potential approach that may open the door to more sustainable and functional SIBs.

Enhancement in rate performance and high voltage structural stability of P3/O3 Na0.9Fe0.5Mn0.45Ni0.05O2 layered oxide cathode

We report synthesis and sodium storage performances of two biphasic P3/O3 materials, Na0.9Fe0.5Mn0.5O2 (P3/O3 NFM) and Na0.9Fe0.5Mn0.45Ni0.05O2 (P3/O3 NFNM). The choice of composition and Ni doping context have been justified. On replacing 5 % Mn by Ni, we found improvements in (de)sodiation capacity and rate performance. The delivered storage capacities of P3/O3 NFM and P3/O3 NFNM in the first cycle between 4.4 and 2.0 V are 118 mAh g−1 and 148 mAh g−1 at C/10 (0.015Ag−1) rate, respectively. The subsequent cycles have a narrow voltage window of 4.2 to 1.9 V for optimized cycling performance. In this voltage window, P3/O3 NFNM demonstrates more than twice the discharge capacity of P3/O3 NFM at 3C rate (0.45Ag−1); further it retains 74 % of its capacity after 200 cycles at 1C rate (0.15Ag−1) as compared to 57 % in P3/O3 NFM. X-ray diffraction studies confirm that Ni doping helps in retaining the P3 phase throughout the charge cycle in P3/O3 NFNM which helps in achieving a higher discharge capacity and better cycling. A greater reduction in the internal resistance, specifically the charge transfer resistance along with enhanced hole conductivity is observed from impedance studies of fully desodiated P3/O3 NFNM due to the maintenance of the P3 phase. XANES studies reveal that the charge compensation mechanism of Fe and Mn changes upon Ni doping which is attributed to the structural stability of P3/O3 NFNM at higher voltages.

Na3MnTi(PO4)3/C composite as an anode for Na-ion batteries with superior rate performance and long-term span

Polyanionic phosphates, one of the Na superionic conductors (NASICON) structured materials, have become the research focus due to their good structural stability, thermal stability, excellent electrochemical performance and long cycle span. Na3MnTi(PO4)3 (NMTP) has been reported as a promising cathode, showing three-electron reaction during cycling with three redox couples of Mn3+/4+ (4.0 V vs. Na+/Na) and Mn2+/3+ (3.5 V) and Ti3+/4+ (2.1 V). Note that the lower redox couple of Ti2+/3+ (0.4 V), due to the further reduction of titanium, endows NMTP the characteristic as an anode for Na-ion batteries. In this work, the Na storage performance and reaction mechanism of NMTP/C in the low potential range of 0.01 – 3.0 V are explored. The NMTP/C composite exhibits a reversible specific capacity of 200 mAh g−1 at 0.1 C, which is superior to the Na3V2(PO4)3/C anode (170 mAh g−1) in the same voltage range. Attractively, NMTP/C composite provides a specific discharge capacity of 71 mAh g−1 at 10.0 C and remains a capacity retention rate of 93.4% after 3000 cycles, showing the superior rate performance and long-term stability. In addition, ex situ XRD and HRTEM are used to reveal the structural evolution of two-phase and single-phase solid solutions during cycling. Our findings confirm that the lower voltage plateau of Ti2+/3+ doubles the sodiation capacity of NMTP and verifies its feasibility as a promising anode for Na-ion batteries.

Sodium compensation and interface protection effects of Na3PS3O for sodium-ion batteries with P2-type oxide cathodes

Irreversible interfacial reactions occurring on non-sodium-containing anodes and P2-type oxide cathodes can significantly reduce the availability of active sodium ions in full-cells, which is unfavorable for realizing high energy density. In this work, we propose the use of oxygen-doped sodium thiophosphate, Na3PS3O (NPSO), as a self-sacrificing cathode additive for sodium compensation in liquid batteries. The uniform dispersion of NPSO into the Na0.66Ni0.26Zn0.07Mn0.67O2 (NNZM) cathode can be realized by a solution-casting method. The continuous irreversible decomposition of NPSO provides a total sodiation capacity of over 300 mAh g−1 with approximately 60% capacity delivered below 4.0 V. Besides compensating for sodium consumption, NPSO and its non-gaseous decomposition products effectively suppress the growth of cathode electrolyte interphase films caused by electrolyte decomposition and the formation of oxygen vacancies in the crystal structure of NNZM. Coating of NPSO on conventional NNZM cathodes leads to an increase in the capacity retention of half-cells from 62.1% to 83.3% and the energy density of full-cells by 29.7%. This work opens up a new application field for sodium thiophosphates.

Vacancy Enabled O3 Phase Stabilization for Manganese‐Rich Layered Sodium Cathodes

Manganese‐rich layered oxide materials hold great potential as low‐cost and high‐capacity cathodes for Na‐ion batteries. However, they usually form a P2 phase and suffer from fast capacity fade. In this work, an O3 phase sodium cathode has been developed out of a Li and Mn‐rich layered material by leveraging the creation of transition metal (TM) and oxygen vacancies and the electrochemical exchange of Na and Li. The Mn‐rich layered cathode material remains primarily O3 phase during sodiation/desodiation and can have a full sodiation capacity of ca. 220 mAh g−1. It delivers ca. 160 mAh g−1 specific capacity between 2–3.8 V with >86 % retention over 250 cycles. The TM and oxygen vacancies pre‐formed in the sodiated material enables a reversible migration of TMs from the TM layer to the tetrahedral sites in the Na layer upon de‐sodiation and sodiation. The migration creates metastable states, leading to increased kinetic barrier that prohibits a complete O3‐P3 phase transition.

High-stability Mn–Co–Ni ternary metal oxide microspheres as conversion-type anodes for sodium-ion batteries

For sodium-ion batteries (SIBs), the electrochemical process for electrodes involves ion transport in the solid electrolyte interphase (SEI) and active materials. Generally, the large ion radius of Na+ is often considered as the key factor in poor electrode kinetics. However, for conversion-type metal oxide anodes with low redox potentials, unstable SEIs as well as the corresponding kinetic barrier also have significant effects on electrochemical behaviors and deserve more attention. Herein, porous and micro-spherical (Mn0.6Co0.3Ni0.1)3O4 is tailored as a SIB anode using co-precipitation. A high Mn percentage is beneficial to the formation of a micro-spherical morphology during co-precipitation. Due to its lack of electrochemical activity, Mn also contributes to the morphological stability of active materials during cycling. This allows for a clear observation regarding morphological changes of SEI products generated at the electrode surface. It is revealed that branch-like products are gradually converted into a dense interphase layer at electrode surfaces during cycling. The unstable and uneven topography of these electrode surfaces generates kinetic barriers that account for low rate capacities of the as-obtained (Mn0.6Co0.3Ni0.1)3O4 materials. The synthesized metal oxide is able to retain 98.1% of its initial sodiation capacity after 2000 cycles at 0.5 A g−1.

Vacancy‐Enabled O3 Phase Stabilization for Manganese‐Rich Layered Sodium Cathodes

AbstractManganese‐rich layered oxide materials hold great potential as low‐cost and high‐capacity cathodes for Na‐ion batteries. However, they usually form a P2 phase and suffer from fast capacity fade. In this work, an O3 phase sodium cathode has been developed out of a Li and Mn‐rich layered material by leveraging the creation of transition metal (TM) and oxygen vacancies and the electrochemical exchange of Na and Li. The Mn‐rich layered cathode material remains primarily O3 phase during sodiation/desodiation and can have a full sodiation capacity of ca. 220 mAh g−1. It delivers ca. 160 mAh g−1 specific capacity between 2–3.8 V with >86 % retention over 250 cycles. The TM and oxygen vacancies pre‐formed in the sodiated material enables a reversible migration of TMs from the TM layer to the tetrahedral sites in the Na layer upon de‐sodiation and sodiation. The migration creates metastable states, leading to increased kinetic barrier that prohibits a complete O3‐P3 phase transition.

Recent Tactics and Advances in the Application of Metal Sulfides as High‐Performance Anode Materials for Rechargeable Sodium‐Ion Batteries

AbstractThe successful development of post‐lithium technologies depends on two key elements: performance and economy. Because sodium‐ion batteries (SIBs) can potentially satisfy both requirements, they are widely considered the most promising replacement for lithium‐ion batteries (LIBs) due to the similarity between the electrochemical processes and the abundance of sodium‐based resources. Among various SIB anode materials, metal sulfides are most extensively studied as materials for high‐performance electrodes due to the versatility of their synthesis procedure, utilization potential, and high sodiation capacity. Herein, some of the most effective strategies aimed at effectively alleviating the performance shortcomings of these materials from the materials engineering/design perspective are summarized. In terms of facilitating ion transport in SIBs, which represents one of the most critical aspects of their performance, a specific family of strategies related to a particular operational mechanism is considered rather than categorizing based‐on individual sulfide materials. In the foreseeable future, the development of highly functional SIBs electrode materials and utilization of metal sulfides will become highly relevant due to their stability and performance characteristics. Therefore, it is anticipated that this review will guide further research and facilitate the realization of various applications of sulfide‐based high‐performance rechargeable batteries.

Pitch Derived Carbon As Light Weight and High-Power Sodium-Ion Battery Anode

Li-ion batteries (LIBs) are fulfilling the current need of humankind, the high abundance, and accessibility of sodium, making Na-ion batteries (NIBs) a promising LIBs supplement in the large-scale energy storage application.1, 2 However, the commercial success of NIBs demands an appropriate cathode and anode material. From the cathode material viewpoint, the literature reports suggest that O3/P2 type layered oxide can deliver a reasonable capacity with good cycling stability2. Graphite, the state-of-art anode material in LIBs is electrochemically inactive to intercalate Na-ions. Na-ion intercalation into graphite lattice is a thermodynamic driven process, where most Na-rich graphite intercalation compounds (GIC) prepared to date is NaC64 with a1 capacity of only 35 mAh g-1.3 However, Li-ion and K-ion form the stage one Li-GIC and K-GIC having the formula LiC6 and KC8, which makes them electronically active in Li- and K-ion battery, respectively. 4,5 To realize the large scale application of sodium-ion batteries, a stable, cost-effective anode is desired. Carbon-based anode materials are always attractive because of ease of fabrication, cost, and feasibility towards practical application. The pioneering work of Dahn and Stevens on hard carbon anode, reports the sodiation capacity of 300 mAh g-1 at room temperature.6 Later on, the hard carbon derived from different precursors such as a polymer, biomass, resin, etc., and applied as anode for Na-ion battery.7 However, hard carbon materials mostly suffer from poor carbon synthesis yield and high cost.8 Therefore, exploring cost-effective precursors and process is very crucial to realize the large scale application of NIB.Pitch is a potential low-cost precursor to synthesize soft carbon anode for NIBs. However, it does not exhibit decent Na-ion storage. Herein, we report the facile synthesis of pitch derived-binder less-metal free-freestanding anode for storing Na-ions by one-step pyrolysis process between the temperature range 700-1000 oC under nitrogen atmosphere. We replace conventional Cu-current collectors with carbon fiber (CFs). The electrode architecture not only eliminates the metallic current collector, conductive diluents and inactive organic binder but also provides an ideal porous network for sodium-ion and electrolyte diffusion into the bulk of the electrode. The freestanding electrode delivers a reversible capacity of 310 mAh g-1 in compare to 180 mAh g-1 for conventional electrode at the current density of 50 mA g-1. The cycling stability over 500 cycles (at 1 A g-1) and C-rate performance of freestanding anode dictate it as a promising anode for NIBs. The overall charge storage properties of conventional and freestanding-film are quantified into pseudocapacitive and diffusion-control Na+ intercalation. Further, the freestanding film is implemented as anode in order to realize its practical application in sodium-ion full cell. It is believed that the study may open up a new approach to modify the pitch based soft-carbon precursors as anode for low-cost, high-energy NIBs. Acknowledgments SG acknowledges MHRD, VKK acknowledges UGC-NET, Govt. of India, and SKM acknowledges Research Center Imarat (DRDO), Hyderabad under grant no. RCI/CAAT/8151/CARS-358 for financial support.

Cu3Ge coated by nitrogen-doped carbon nanorods as advanced sodium-ion battery anodes

The sodium storage performance of Ge-based materials suffers from poor cycling stability caused by the volume variation and collapse of the structure during cycling process. In this work, Cu3Ge coated by nitrogen-doped carbon (Cu3Ge-NC) nanorods are prepared by annealing the mixture of CuGeO3 nanowires and polyacrylonitrile which acts as nitrogen and carbon source. As anode materials for sodium ion batteries, the outside carbon shell inhibits the serious volume change caused by Na+ insertion/extraction, and the Cu3Ge alloy enhances the sodiation capacity with rapid electron transfer and fast reaction kinetics. Corresponding kinetic analysis indicates pseudocapacitive behaviors play a dominant role in the total capacity at high rates. Hence, the Cu3Ge-NC exhibits favorable rate capability and cycling stability, which delivers a reversible capacity of 160 mAh g−1 for 500 cycles at a current density of 100 mA g−1.

Influence of P doping on Na and K storage properties of N-rich carbon nanosheets

Nitrogen or phosphorus doping is a commonly used method to ameliorate the electrochemical properties of carbonaceous material. In this study, nitrogen-rich carbon nanosheets are first prepared and then annealed with NaH2PO4 to synthesize phosphorus doping nitrogen-rich carbon nanosheets. Two obtained materials are utilized as anodes of sodium-ion batteries and potassium-ion batteries, revealing that phosphorus doping can improve sodiation capacity (247.9 vs. 175.1 mA h g−1) and lower potassiation capacity (207.2 vs. 242.6 mA h g−1). To explore the inner reason for this phenomenon, Na+ and K+ diffusion coefficients are surveyed through galvanostatic intermittent titration technique, showing that the electrode with large ion diffusion coefficient delivers a large capacity. This work provides some use for reference in introduction of heteroatoms to carbonaceous anode materials of sodium-ion batteries and potassium-ion batteries.

A renewable natural cotton derived and nitrogen/sulfur co-doped carbon as a high-performance sodium ion battery anode

Here we report a new N/S co-doped carbon nanosheets derived from a renewable natural cotton source and its performance as an anode for SIBs. The electrochemical testing shows that the new carbon anode outperforms other major carbon-based anodes in sodiation capacity (482.1 mAh g−1 at 0.1 A g−1), rate performance (375.6, 357.8, 340.5, 324.1 mAh g−1 at 1.0, 2.0, 5.0 and 10.0 A g−1, respectively) and cycling stability (351.1 mAh g−1 at 2.0 A g−1 for 600 cycles). The defects, enlarged d-spacing, reduced Na+ diffusion barrier and increased electronic conductivity of the fabricated N/S co-doped carbon nanosheets are responsible for the excellent Na+ storage property, while the pseudocapacitive behavior of Na+ storage contributes to their high rate performance. This work demonstrates a low-cost path forward to fabricate high-performance carbonaceous anode materials for SIBs.

Electrochemical Performance of NaFeFe(CN)6 Prepared by Solid Reaction for Sodium Ion Batteries

Commercially available Na4Fe(CN)6 and Fe4[Fe(CN)6]3 are two cheap compounds that have ever been investigated as positive electrode materials for sodium-ion batteries. However, poor electronic conductivity of Na4Fe(CN)6 and sodium deficiency of Fe4[Fe(CN)6]3 prevent these two materials from being used in practical rechargeable sodium-ion batteries. In this paper, a NaFeFe(CN)6 cathode material was synthesized by ball milling the Fe4[Fe(CN)6]3/ Na4Fe(CN)6 mixture. The obtained NaFeFe(CN)6 demonstrated a single cubic phase indexed to Fm3m space group similar to Fe4[Fe(CN)6]3 but with larger lattice parameter due to the existence of Na+ in the lattice framework. The NaFeFe(CN)6 electrode delivered first desodiation capacity of 119.4 mAh g−1 and first sodiation capacity of 153.6 mAh g−1 at 0.05C rate. The NaFeFe(CN)6 showed excellent cycling stability with reversible capacities of 118.2 mAh g−1 and 96.8 mAh g−1 at 0.1C and 1C rate, respectively. In-situ XRD analyses demonstrated a single cubic phase process during charge-discharge of NaFeFe(CN)6 electrode. Low water content benefited from the solid reaction method and the homogenous single phase process during charge/discharge assured the stable long term cycling performance of the NaFeFe(CN)6 product.

In situ X-ray diffraction investigation of CoSe2 anode for Na-ion storage: Effect of cut-off voltage on cycling stability

Owing to their high specific capacity, transition metal chalcogenides (TMCs) based materials attract enormous attentions for energy storage, yet the performance decay observed in TMCs anodes are strongly depended on the host material and working conditions. Here we report CoSe2 nanorods as a promising alternative for sodium-ion batteries (SIBs), which are fabricated by a facile hydrothermal strategy. At upper cut-off voltage of 0.4 V, the as-prepared sample can demonstrate improved sodiation capacity, rate capability, and cycling stability (a high capacity of 386 mAh g−1 at 5 A g−1 even after 2000 cycles). In situ XRD and ex situ TEM measurements are utilized to investigate phase transition behavior of CoSe2 nanorods in the initial 9 sodiation/desodiation cycles. The high electrochemical reversibility of CoSe2 nanorods within the potential window of 0.4–3.0 V is ascribed to that the deep conversion reaction below 0.4 V is effectively avoided, thus the volume expansion and pulverization of CoSe2 nanorods are efficiently suppressed. It convinces that applying suitable and optimal cut-off voltage is a useful approach to regulate the reactions progress for TMCs anode, improving their cycling and structure stability.

Melt-Spun Fe–Sb Intermetallic Alloy Anode for Performance Enhanced Sodium-Ion Batteries

Owing to the high theoretical sodiation capacities, intermetallic alloy anodes have attracted considerable interest as electrodes for next-generation sodium-ion batteries (SIBs). Here, we demonstrate the fabrication of intermetallic Fe-Sb alloy anode for SIBs via a high-throughput and industrially viable melt-spinning process. The earth-abundant and low-cost Fe-Sb-based alloy anode exhibits excellent cycling stability with nearly 466 mAh g-1 sodiation capacity at a specific current of 50 mA g-1 with 95% capacity retention after 80 cycles. Moreover, the alloy anode displayed outstanding rate performance with ∼300 mAh g-1 sodiation capacity at 1 A g-1. The crystalline features of the melt-spun fibers aid in the exceptional electrochemical performance of the alloy anode. Further, the feasibility of the alloy anode for real-life applications was demonstrated in a sodium-ion full-cell configuration which could deliver a sodiation capacity of over 300 mAh g-1 (based on anode) at 50 mA g-1 with more than 99% Coulombic efficiency. The results further exhort the prospects of melt-spun alloy anodes to realize fully functional sodium-ion batteries.