NASICON-type Na3V2 Research Articles

Sodium-ion battery using a NASICON-type Na3V2(PO4)3 cathode: quantification of diffusive and capacitive Na+ charge storage

In this present work, NASICON-type Na3V2(PO4)3 cathode was synthesized by sol-gel and solid-state routes for sodium-ion battery. The diffusive and capacitive Na+ charge storage modes at peak and non-peak potential regions were quantified.

Sosnowskyi Hogweed-Based Hard Carbons for Sodium-Ion Batteries

Sodium-ion battery technology rapidly develops in the post-lithium-ion landscape. Among the variety of studied anode materials, hard carbons appear to be the realistic candidates because of their electrochemical performance and relative ease of production. This class of materials can be obtained from a variety of precursors, and the most ecologically important and interesting route is the synthesis from biomass. In the present work, for the first time, hard carbons were obtained from Heracleum sosnowskyi, a highly invasive plant, which is dangerous for humans and can cause skin burns but produces a large amount of green biomass in a short time. We proposed a simple synthesis method that includes the pretreatment stage and further carbonization at 1300 °C. The effect of the pretreatment of giant hogweed on the hard carbon electrochemical properties was studied. Obtained materials demonstrate >220 mAh g−1 of the discharge capacity, high values of the initial Coulombic efficiency reaching 87% and capacity retention of 95% after 100 charge-discharge cycles in sodium half-cells. Key parameters of the materials were examined by means of different analytical, spectroscopic and microscopic techniques. The possibility of using the giant hogweed-based hard carbons in real batteries is demonstrated with full sodium-ion cells with NASICON-type Na3V2(PO4)3 cathode material.

Scalable synthesis of Na3V2(PO4)3/C with high safety and ultrahigh-rate performance for sodium-ion batteries

NASICON-type Na3V2(PO4)3 is a promising electrode material for developing advanced sodium-ion batteries. Preparing Na3V2(PO4)3 with good performance by a cost-effective and large-scale method is significant for industrial applications. In this work, a porous Na3V2(PO4)3/C cathode material with excellent electrochemical performance is successfully prepared by an agar-gel combined with freeze-drying method. The Na3V2(PO4)3/C cathode displayed specific capacities of 113.4 mAh·g−1, 107.0 mAh·g−1 and 87.1 mAh·g−1 at 0.1 C, 1 C and 10 C, respectively. For the first time, the 500-mAh soft-packed symmetrical sodium-ion batteries based on Na3V2(PO4)3/C electrodes are successfully fabricated. The 500-mAh symmetrical batteries exhibit outstanding low temperature performance with a capacity retention of 83% at 0 °C owing to the rapid sodium ion migration ability and structural stability of Na3V2(PO4)3/C. Moreover, the thermal runaway features are revealed by accelerating rate calorimetry (ARC) test for the first time. Thermal stability and safety of the symmetrical batteries are demonstrated to be better than lithium-ion batteries and some reported sodium-ion batteries. Our work makes it clear that the soft-packed symmetrical sodium ion batteries based on Na3V2(PO4)3/C have a prospect of practical application in high safety requirement fields.

Reversible multielectron redox in NASICON cathode with high energy density for low-temperature sodium-ion batteries

The NASICON-type Na3V2(PO4)3 cathode based on vanadium multiple redox is particularly attractive for large-scale sodium-ion battery application. In this work, it was found that the reversible redox of V4+/V5+ can be activated by replacing a part of V3+ with Al3+, obtaining Na3V1.5Al0.5(PO4)3 with typical NASICON phase structure and offering a reversible specific capacity of 163 mAh g−1 through a three-electron redox reaction with a small volume change (2.62%). The most surprising thing is that in addition to favorable room temperature electrochemical performance, Na3V1.5Al0.5(PO4)3 also exhibits a superior low temperature (-20 °C) cycling stability with a capacity retention of 98.9% after 1000 cycles at 5 C. Thin and conformal CEI film as well as stable phase structure across a broad temperature range are responsible for this superior electrochemical property. A Na+ storage mechanism consisting of two-phase and solid-solution electrochemical reactions for Na3V1.5Al0.5(PO4)3 cathode is elucidated via ex-situ XRD structural analysis. DFT calculations indicate that Al3+ substitution could manipulate the localized electronic state and strengthen the oxygen ligand skeleton in the NASICON matrix. Hence, the Na3V1.5Al0.5(PO4)3 cathode renders a slight lattice variation upon the repeated desodiation and sodiation and enhanced Na+ diffusion rate along with low charge transfer resistance.

Unveiling Zn substitution and carbon nanotubes enwrapping in Na3V2(PO4)3 with high performance for sodium ion batteries: Experimental and theoretical study

NASICON-type Na3V2(PO4)3 (NVP) is regarded as a prospective cathode material for sodium-ion batteries (SIBs). However, its electrochemical performance is restricted by poor intrinsic conductivity. Herein, we prepare Na3V2(PO4)3 with Zn2+ ions doping via sol-gel method and enwrap it by carbon nanotubes (CNTs), in which CNTs act as conductive regent. The combined effects of CNTs and Zn2+ ions, especially for Na3.07V1.93Zn0.07(PO4)3@CNTs composite, greatly improving the kinetic performance of pristine NVP. Specifically, Na3.07V1.93Zn0.07(PO4)3@CNTs composite possesses an initial capacity of 114.9 mAh g−1, close to the theoretical value (117.6 mAh g−1). Moreover, the composite exhibits a discharge capacity of 86.9 mAh g−1 at 15 C after 500 cycles with the retention rate of approximately 90.7%, demonstrating its high cyclic stability in long-cycling tests. Our theoretical results demonstrate that both the band gap and migration energy barrier can be reduced by Zn2+ substitution, which explains the improved electrical conductivity and ion diffusion rate. Overall, this design principle provides a promising method for fabricating Na3V2(PO4)3 material as high-performance sodium-ion batteries.

Langmuir-Blodgett deposited Na3V2(PO4)3-MnO2 nanocomposite thin film electrodes for hybrid energy storage application

This article deals with the Langmuir-Blodgett deposition of NASICON type Na3V2(PO4)3 (NVP) -MnO2 nanocomposite thin-film for the hybrid energy storage application. The nanocomposite electrode with various NVP: MnO2 ratio was developed and their physiochemical properties were examined with advanced characterisation techniques. The aqueous half-cell was made using the developed nanocomposite electrodes, to study their energy storing behaviour by CV and GCD analysis. In comparison, the 3:1 ratio of NVP-MnO2 (NM3) exhibits a higher specific capacity with good cyclic stability and rate capability. The higher MnO2 concentration leads to the dominance of pseudo capacitance behaviour over the battery like reaction, resulted in the variation of energy density and power density between 39 and 18 Wh/Kg and 3479–4450 W/Kg.

Modification of the morphology of Na3V2(PO4)2F3 as cathode material for sodium-ion batteries by polyvinylpyrrolidone

NASICON-type Na3V2(PO4)2F3 (NVPF) is proposed to be a potential cathode material for sodium-ion battery because of its good structural stability, relatively high capacity and voltage platform. Nonetheless, the poor-rate performance, resulting from its low conductivity, has become a massive obstacle to its practical application. In this work, carbon coating together with morphology controlling were introduced to solve the issue of NVPF. This experiment used a hydrothermal method to prepare Na3V2(PO4)2F3@C (NVPF@C) and explored the impact of surfactants (polyvinylpyrrolidone (PVP)) on the positive material performance of sodium-ion battery. Through various characterisation, NVPF@C compared its performance with that of untreated products, and verified that appropriate surfactant modification could enhance the performance of the electron conduction and sodium ion diffusion, thus effectively improved the performance of NVPF. Through comparison, it was found that appropriate surface modification with PVP can achieve the effects of specific crystal surface exposure and clusters of porous micron ball structure, and improve the electrochemical performance of NVPF best. Under the charge and discharge ratio of 0.2C, its initial reversible capacity was 127.8 mA h g−1. After 100 cycles, its discharge capacity was 106.1 mA h g−1, and the cycling retention rate reached 82.8%. Compared to the original NVPF, its performance has been dramatically improved.

High Performance Sodium Secondary Batteries Using Ionic Liquid Electrolytes

Sodium secondary batteries are attracting more and more attention as large-scale energy storage devices owing to high abundance and low cost of sodium resources.[1-3] Ionic liquid electrolytes have unique properties such as low volatility, low flammability, and thermal stability and enable construction of safe electrochemical devices, including sodium secondary batteries.[4,5] In particular, intermediate temperature operation of sodium secondary batteries using ionic liquid electrolytes is attractive by considering the improvement of battery performance. Such environments are ubiquitous in our daily life or industries and can be achieved with minimal extra energy. Self-heating of batteries can also contribute to operation at elevated temperatures.Highly improved performance is observed for some electrode materials by intermediate-temperature operation of sodium secondary batteries with bis(fluorosulfonyl)amide-based ionic liquid electrolytes. As for the sodium metal negative electrode, morphology of sodium metal electrodeposit is significantly dependent on operation temperature; smooth sodium metal deposition with a high deposition/dissolution efficiency is observed at 90 deg C. High rate performance is observed for a number of positive electrode materials. The NASICON-type Na3V2(PO4)3 especially provides a long cycle life, exhibiting more than 5000 cycles at 90 deg C in a half cell configuration at a rate of 2C, which is also due to the high cycleability of sodium metal electrode.[6] Metal phosphide negative electrodes also show improved rate and cycle performance by intermediate-temperature operation. The copper phophide-carbon composite, CuP2/C, electrode prepared by high-energy ball-milling shows a stable cycling based on a conversion mechanism at 90 deg C over 300 cycles.[7]Na metal is used as a counter electrode in a half-cell configuration to test electrode performance for Na secondary batteries, but its unstability and large interfacial resistance causes unreliable results, especially at high rates. The Na3V2(PO4)3 and NaV2(PO4)3 electrode prepared by mixing them in a target ratio exhibits a flat plateau at 3.4 V vs. Na+/Na and lower polarization than the Na metal. This new electrode enables trustable electrochemical evaluation of a target electrode even at a temperature above the melting point of Na metal.[8]

Phase boundary propagation kinetics predominately limit the rate capability of NASICON-type Na3+xMnxV2-x(PO4)3 (0≤x≤1) materials

NASICON-type Na3V2(PO4)3 cathode materials can be regarded as promising candidates for high-power Na-ion batteries due to the observed facile kinetics of Na-ion de/intercalation. Substitution of V for Mn provides additional advantages related to the increase in the average operating potential and reduced cost of the active material. In this work, we explore the kinetics of Na+ intercalation into Mn-substituted Na3+xMnxV2-x(PO4)3 (x = 0, 0.1, 0.5, 1) materials with a primary focus on the impact of Mn content on the rate capability of the materials. We demonstrate that Mn substitution results in quite subtle changes in bulk ionic diffusivity and charge transfer rates, while more significant impact is observed on the nucleation kinetics, which induces large hysteresis between charge and discharge curves for Mn-rich materials. The increase in hysteresis between charge and discharge curves does not limit the specific energy retention at high C-rates significantly, yet the performance losses are mainly related to the slow phase boundary propagation for biphasic processes. The Mn-rich materials, which demonstrate wider single-phase regions, are shown to outperform the unsubstituted materials in terms of rate-capability and should be preferred for high-power applications.

Dual-Nitrogen-Doped Carbon Decorated on Na3V2(PO4)3 to Stabilize the Intercalation of Three Sodium Ions

NASICON-type Na3V2(PO4)3 (NVP) has been regarded as one of the most promising cathode materials for high-voltage sodium-ion batteries (SIBs) because of its high theoretical energy density and stabl...

Porous Na3V2(PO4)3/C as cathode material for high-rate sodium-ion batteries by sacrificed template method

NASICON-type Na3V2(PO4)3 with a three-dimensional open framework structure has attracted wide attention, and it is regarded as one of the most promising cathode material for sodium-ion batteries. However, the low electronic conductivity restricts its charge–discharge capacity and electrochemical performance. With the purpose to solve this problem, polystyrene microspheres are applied in the preparation of cathode materials for sodium-ion batteries. Particular porous-structured Na3V2(PO4)3 composing of interlaced nanosheets is obtained samples by a simple hydrothermal-assisted sol–gel method via a self-sacrificed template (polystyrene microsphere). As expected, the as-prepared porous sample delivers a reversible capacity of 109.2 mAh g−1 at 0.2 C, an excellent rate performance (89.6 mAh g−1 at 50 C) and superior cyclic stability (retention of 94% over 500 cycles at 50 C). The outstanding rate and cyclic performance are attributed to its unique porous structure which is conducive to improve electron conductivity and facilitate the diffusion of sodium ions.

A Long-Cycling Aqueous Zinc-Ion Pouch Cell: NASICON-Type Material and Surface Modification.

Aqueous zinc-ion batteries (ZIBs) have become the highest potential energy storage system for large-scale applications owing to the high specific capacity, good safety and low cost. In this work, a NASICON-type Na3 V2 (PO4 )3 cathode modified by a uniform carbon layer (NVP/C) has been synthesized via a facile solid-state method and exhibited significantly improved electrochemical performance when working in an aqueous ZIB. Specifically, the NVP/C cathode shows an excellent rate capacity (e. g., 48 mAh g-1 at 1.0 A g-1 ). Good cycle stability is also achieved (e. g., showing a capacity retention of 88% after 2000 cycles at 1.0 A g-1 ). Furthermore, the Zn2+ (de)intercalation mechanism in the NVP cathode has been determined by various ex-situ techniques. In addition, a Zn||NVP/C pouch cell has been assembled, delivering a high capacity of 89 mAhg-1 at 0.2 A g-1 and exhibiting a superior long cycling stability.

High Voltage Activation of the Nasicon-Type Na4mnv(PO4)3 Cathode Studied By Operando X-Ray Diffraction

NASICON-type Na3V2(PO4)3 delivers a highly reversible capacity of more than 110 mAh/g, showing a voltage plateau at 3.4 V corresponding to the V4+/V3+ redox couple [1]. In Na3+xMnxV2-x(PO4)3, introduction of Mn(II) lowers the cost of the material and enhances the operation voltage compared to that in Na3V2(PO4)3 [2]. Here, we studied the phase transformation behavior of Na4MnV(PO4)3 upon charge and discharge within different voltage limits. In Na4MnV(PO4)3 two well-defined steps are observed when charged to 3.8 V [2]. After the increase of the cut-off voltage on charge up to 4.0V the electrochemical behavior on discharge changes, namely instead of two steps as in the case of cut-off at 3.8V a gradual slope is observed [3]. By operando synchrotron X-ray powder diffraction we’ve found that symmetry reduction from rhombohedral to monoclinic occurs immediately after the start of the electrochemical desodiation, with restoring of the rhombohedral phase at 3.8 V [4]. Cycling within 2.5-3.8 V potential range proceeds through both solid solution (Na4MnV(PO4)3↔ Na3MnV(PO4)3) and two-phase (Na3MnV(PO4)3↔ Na2MnV(PO4)3) processes. An additional voltage plateau at ~3.8-4.0 V vs. Na/Na+ is observed, associated with re-distribution of Na cations over available crystallographic positions and “unlocking” of the Na1 site in the rhombohedral phase. Reverse insertion of Na+ cations proceeds via a complete solid solution region. The experimentally observed reversible electrochemical capacity increases by ≈14% after raising cut-off voltage. This work was supported by the Russian Science Foundation (Grant No. 17-73-30006). Reference s : [1] K. Saravanan; C. W. Mason; A. Rudola; K. H. Wong; P. Balaya. The First Report on Excellent Cycling Stability and Superior Rate Capability of Na3V2(PO4)3 for Sodium Ion Batteries. Adv. Energy Mater. 2013, 3, 444−450. [2] W. Zhou; L. Xue; X. Lü; H. Gao; Y. Li; S. Xin; G. Fu; Z. Cui; Y. Zhu; J.B. Goodenough. NaxMV(PO4)3 (M = Mn, Fe, Ni) Structure and Properties for Sodium Extraction. Nano Letters, 2016, 16 (12), 7836-7841 [3] F. Chen; V. M. Kovrugin; R. David; O. Mentré; F. Fauth; J.-N. Chotard; C. Masquelier. A NASICON-Type Positive Electrode for Na Batteries with High Energy Density: Na4MnV(PO4)3. Small Methods, 2018, 2, 1800218 [4] M.V. Zakharkin; O.A. Drozhzhin; I.V. Tereshchenko; D. Chernyshov; A.M. Abakumov; E.V. Antipov; K.J. Stevenson. Enhancing Na+ Extraction Limit through High Voltage Activation of the NASICON-Type Na4MnV(PO4)3 Cathode. ACS Applied Energy Materials, 2018, 11 (1), 5842-5846 Figure 1

Na3V2(PO4)3@Carbon Nanofibers: High Mass Loading Electrode Approaching Practical Sodium Secondary Batteries Utilizing Ionic Liquid Electrolytes

Practical sodium secondary batteries require high power, high energy density, and long cyclability. The NASICON-type Na3V2(PO4)3 (NVP) is often investigated as a positive electrode material due to its high operation voltage, structural stability, and high Na+ ion conductivity. To overcome its low electronic conductivity, NVP requires carbon-coating or the addition of conductive materials for practical use. In this study, carbon nanofibers (CNFs) are incorporated as a conductive material along with glucose for carbon coating and fixing CNF frames to NVP particles. Uniform NVP composite and CNFs network (NVPC@CNFs) are obtained by a combination of sonication and the sol–gel method. Electrochemical measurements using a high mass loading electrode around ∼8.5 mg-active material cm–2 and Na[FSA]-[C2C1im][FSA] (C2C1im = 1-ethyl-3-methylimidazolium, FSA = bis(fluorosulfonyl)amide) ionic liquid electrolyte suggest safe operations of sodium secondary batteries up to intermediate temperatures (∼373 K). The rate performance further improved by using the NVPC@CNFs compared to NVPC and exhibited a high rate capability (at high geometric current density) of 51.1 mAh g–1 at 10C (10.0 mA cm–2) at 298 K and 82.3 mAh g–1 at 100C (100 mA cm–2) at 363 K (1C = 118 mA g–1, 1.00 mA cm–2). Furthermore, this material with an ionic liquid electrolyte exhibited superior Coulombic efficiencies over 3000 cycles of 99.9%. Electrochemical measurements (electrical impedance spectroscopy, charge–discharge test, cycle test, and rate performance test) clarify the electrochemical characteristics of this material.

Insight into Preparation of Fe-Doped Na3V2(PO4)3@C from Aspects of Particle Morphology Design, Crystal Structure Modulation, and Carbon Graphitization Regulation.

The peak-loading shift function of sodium-ion batteries in large-grid energy store station poses a giant challenge on the account of poor rate performance of cathodes. NASICON type Na3V2(PO4)3 with a stable three-dimensional framework and fast ion diffusion channels has been regarded as one of the potential candidates and extensively studied. Nevertheless, a multilevel integrated tactic to boost the performance of Na3V2(PO4)3 in terms of crystal structure modulation, coated carbon graphitization regulation, and particle morphology design is rarely reported and deserves much attention. In this study, organic ferric was used to prepare Fe-doped Na3V2(PO4)3@C cathode on the account of low cost, environmental friendliness, and catalytic function of Fe on carbon graphitization. The density functional theory calculation depicts that the most stable site for Fe atom is the V site and moderate replacement of Fe at V position would reduce the band gap energy from 2.19 by 0.43 eV and improve the electron transfer, which is crucial for the intrinsic poor conductivity of Na3V2(PO4)3. The experimental results show that Fe element can be introduced into the bulk structure successfully, modulating relevant structural parameters. In addition, the coated carbon layer graphitization degree is also regulated due to the catalysis function of Fe. And, the decomposition of organic ferric would infuse the formation of porous structure, which can promote electrolyte permeation and shorten the electron/ion diffusion. Finally, the optimized Na3V1.85Fe0.15(PO4)3@C could possess a high capacity of 103.69 mA h g-1 and retain 91.45% after 1200 cycles at 1.0C as well as 94.45 mA h g-1 at 20C. In addition, the excellent performance is comprehensively elucidated via ex situ X-ray diffraction and pseudocapacitance characterization. The multifunction contribution of Fe-doping may provide new clue for designing porous electrode materials and a new sight into Fe-doped carbon-coated material.

Phosphorus-doped graphene-improved Na3V2(PO4)3@C nanocomposite possessing high-rate performance for electrochemical energy storage

Abstract NASICON-type Na3V2(PO4)3 is a promising cathode for sodium-ion batteries owing to its low cost and great thermal stability as well as high energy density, which has attracted ever growing attention. Nevertheless, the pure Na3V2(PO4)3 possesses a bad electrical conductivity, which hinders its Na+-storage performance for energy storage. Designing and fabrication of the phosphorus-doped graphene-decorated Na3V2(PO4)3@C nanocomposite is performed in this research by a simple and rapid method. The constructed network by phosphorus-doped graphene sheet and carbon layer can greatly strengthen the electron and ionic conductivities of Na3V2(PO4)3, leading to outstanding rate capacity together with cyclic property. The as-fabricated electrode shows a specific capacity of 110.6 mAh g−1 at 0.5 C and a high capacity retention of 91.2% over 500 cycles at 20 C. Therefore, this designed nanocomposite is thought as a prospective cathode for batteries that utilize sodium ion as the charge carrier.

Mo-doped Na3V2(PO4)3@C composites for high stable sodium ion battery cathode

NASICON-type Na3V2(PO4)3 (NVP) with superior electrochemical performance has attracted enormous attention with the development of sodium ion batteries. The structural aggregation as well as poor conductivity of NVP hinder its application in high rate perforamance cathode with long stablity. In this paper, Na3V2-xMo x (PO4)3@C was successfully prepared through two steps method, including sol-gel and solid state thermal reduction. The optimal doping amount of Mo was defined by experiment. When x was 0.15, the Na3V1.85Mo0.15(PO4)3@C sample has the best cycle performance and rate performance. The discharge capacity of Na3V1.85Mo0.15(PO4)3@C could reach 117.26 mA·h·g-1 at 0.1 C. The discharge capacity retention was found to be 94.5% after 600 cycles at 5 C.

Rational Synthesis and Assembly of Ni3S4 Nanorods for Enhanced Electrochemical Sodium-Ion Storage.

Even though advocated as the potential low-cost alternatives to current lithium-ion technology, the practical viability of sodium-ion batteries remains illusive and depends on the development of high-performance electrode materials. Very few candidates available at present can simultaneously meet the requirements on capacity, rate capability, and cycle life. Herein, we report a high-temperature solution method to prepare Ni3S4 nanorods with uniform sizes. These colloidal nanorods readily self-assemble side by side and form microsized superstructures, which unfortunately negates the nanoscale feature of individual nanorods. To this end, we further introduce two-dimensional graphene nanosheets as the spacer to interrupt nanorod self-assembly. Resultant composite presents a marked advantage toward electrochemical storage of Na+ ions. We demonstrate that in half-cells it exhibits large reversible specific capacity in excess of 600 mAh/g, high rate capability with >300 mAh/g retained at 4 A/g, and great cycle life at different current rates. This anode material can also be combined with the NASICON-type Na3V2(PO4)3 cathode in full cells to enable large capacity and good cyclability.

NASICON-type Na3V2(PO4)3 as a new positive electrode material for rechargeable aluminium battery

Although rechargeable aluminium-ion batteries could be very promising, there are only a few materials described in the literature that can insert aluminium. NASICON-type Na3V2(PO4)3 (NVP) is here investigated as a new positive electrode, using aluminium chloride dissolved in O2-free water as electrolyte solution. The reversible capacity is around 60–100 mAh g−1, depending on the cycling conditions. The electrochemical, analytical, NMR, XPS and XRD results all together corroborate that sodium is deinserted during first charge and then aluminium is inserted during the discharge. Both bulk insertion and surface capacitance can contribute to the specific capacity. This is the first report about true insertion of a trivalent cation into a NASICON-type structure. In addition, this material is also electrochemically active vs. Al metal in non-aqueous cell, using ionic liquid as electrolyte solution, with a revesible capacity about 60–70 mAh g−1 at ca. 1.25 V vs. Al. However, in the case of using ionic liquid, sodium (and not aluminium) is reversibly (de)inserted [23]. The results demonstrate that NVP is promising as electrode for rechargeable aluminium batteries, and that the electrolyte solution strongly influence on the electrochemical reaction.

Sodium Superionic Conductor-Type Sodium Vanadium Fluorophosphates for Rechargeable Sodium-Ion Batteries

Owing to the increasing demand for the electrochemical energy storage devices with sufficient capacity, high reliability and low cost, rechargeable sodium-ion batteries (SIBs) have recently regarded as alternative candidates to lithium-ion batteries (LIBs) because of their benefits on material abundance, cost-effectiveness and electrochemical similarities. However, the energy density delivered from the current SIBs is still not comparable with that of the LIBs, which was ascribed to the lower cell voltage. Therefore, developing the cathode materials with higher redox potentials is eagerly anticipated. As one of the most promising cathode materials, carbon-coated sodium vanadium fluorophosphates (Na3V2(PO4)2F3/C) nanocomposites have been extensively investigated due to the merits of their sodium superionic conductor (NASICON) structures for facile ionic transportations, high voltage and high capacity. In this study, the Na3V2(PO4)2F3/C nanoparticles were synthesized using a wet-chemistry route, followed by calcination in an argon atmosphere. The resulting powders were characterized by powder X-ray diffractometer, electron microscopes and thermogravimetric analyzer to confirm their crystalline structure, morphologies and amount of carbon loading, respectively. Benefiting from the nanostructures and continuous carbon coatings, the outstanding reversible capacity (128 mAh/g@0.1 A/g), rate capability (106 mAh/g@1.0 A/g) and capacity retention (98.2 %@100 cycles@1.0 A/g) were achieved as demonstrated by galvanostatic testing. Given the improved electrochemical properties, the NASICON-type Na3V2(PO4)2F3/C nanoparticles synthesized in the present study were anticipated to function as efficient cathode materials for SIBs. Acknowledgement: We gratefully acknowledge financial support from the Bureau of Energy (BOE), Ministry of Economy Affair (MOEA), Taiwan.