Application In Sodium-ion Batteries Research Articles

Tin-Based Anode Materials for Stable Sodium Storage: Progress and Perspective.

Because of concerns regarding shortages of lithium resources and the urgent need to develop low-cost and high-efficiency energy-storage systems, research and applications of sodium-ion batteries (SIBs) have re-emerged in recent years. Herein, recent advances in high-capacity Sn-based anode materials for stable SIBs are highlighted, including tin (Sn) alloys, Sn oxides, Sn sulfides, Sn selenides, Sn phosphides, and their composites. The reaction mechanisms between Sn-based materials and sodium are clarified. Multiphase and multiscale structural optimizations of Sn-based materials to achieve good sodium-storage performance are emphasized. Full-cell designs using Sn-based materials as anodes and further development of Sn-based materials are discussed from a commercialization perspective. Insights into the preparation of future high-performance Sn-based anode materials and the construction of sodium-ion full batteries with a high energy density and long service life are provided.

Graphene-like ultrathin bismuth selenide nanosheets as highly stable anode material for sodium-ion battery

Sodium-ion batteries have high potential for next-generation battery system because of their cost-effective and similar energy-storage mechanism to lithium-ion batteries. However, the commercial graphite anode for lithium-ion batteries cannot be applied to sodium-ion batteries. The lower rate performance and poor cycling life of existing anode materials are major bottlenecks to prospective application in sodium-ion batteries. To address this issues, we synthesize a novel ultrathin Bi2Se3 layered nanosheets that enhance sodium-ion storage performance due to its stable graphene-like structure. Benefiting from the layered nanosheets morphology, as-prepared anode material exhibit excellent electrochemical performance, which can deliver an initial high capacity of 650 mA h g−1 (Na+ storage) at 0.1 A/g along with outstanding stability. The ultrathin Bi2Se3 layered nanosheets with a thickness of ~6 nm offer a large electrode-electrolyte contact interface due to its porous morphology. Ex-situ transmission electron microscopy analysis and electrochemical impedance spectroscopy measurement reveals the structural stability of bismuth selenide nanosheets during repeated sodium-ion insertion and extraction process. The superior electrochemical performance and unique graphene-like architecture of the layered bismuth selenide nanosheets offer a promising anode for commercial sodium-ion batteries.

General synthesis of yolk-shelled FexQy@Carbon (Q = S, Se, P) film for high performance anode of sodium-ion batteries

Sodium-ion batteries (SIBs) have attracted widespread attention because of the economic benefit of low-cost and abundance of sodium resources. Iron-based electrodes (sulfide, selenide and phosphide) that operate through conversion mechanism have shown huge potential for excellent sodium-ion storage. However, the problems related with serious volume expansion and lack of general synthesis methods of iron-based materials shorten the cycle life and hindered their application in SIBs. Herein, a general synthetic strategy of electrospinning process was developed to achieve the yolk-shelled FexQy@C (Q = S, Se and P) film for binder-free anode of high-performance SIBs. Such method has more precursor materials to choose from and is highly scalable. More importantly, the designed electrodes have a unique yolk-shell structure and a three-dimensional conductive network. When applied as a binder-free anode of SIBs, all three samples exhibit outstanding sodium storage performance (FeS2@C-40: remaining 280 mAh g−1 after 400 cycles at 1 A g−1, Fe7Se8@C-40: remaining 186.5 mAh g−1 after 200 cycles at 0.1 A g−1 and FeP4@C-40: remaining 205 mAh g−1 after 1000 cycles at 0.5 A g−1). Therefore, the scalability and universality of this general synthetic strategy can open up a new direction for the exploration of high-energy density and flexible electrode materials.

Dopant-Free Main Group Elements Supported Covalent Organic–Inorganic Hybrid Conducting Polymer for Sodium-Ion Battery Application

Dopant-Free Main Group Elements Supported Covalent Organic–Inorganic Hybrid Conducting Polymer for Sodium-Ion Battery Application

Challenges and Applications of Flexible Sodium Ion Batteries

Sodium-ion batteries are considered to be a future alternative to lithium-ion batteries because of their low cost and abundant resources. In recent years, the research of sodium-ion batteries in flexible energy storage systems has attracted widespread attention. However, most of the current research on flexible sodium ion batteries is mainly focused on the preparation of flexible electrode materials. In this paper, the challenges faced in the preparation of flexible electrode materials for sodium ion batteries and the evaluation of device flexibility is summarized. Several important parameters including cycle-calendar life, energy/power density, safety, flexible, biocompatibility and multifunctional intergration of current flexible sodium ion batteries will be described mainly from the application point of view. Finally, the promising current applications of flexible sodium ion batteries are summarized.

High-voltage structural evolution and its kinetic consequences for the Na4MnV(PO4)3 sodium-ion battery cathode material

The recently demonstrated possibility of high-voltage extraction of more than 2 Na ions per Na4MnV(PO4)3 formula unit is considered as a possible way to increase the specific energy of this material, which would open up prospects for its application in sodium-ion batteries. However, for the Na4MnV(PO4)3 material and for a wide group of related NASICON-structured materials, high-voltage Na extraction was demonstrated to lead to a rapid decrease in capacity and a sharp increase in hysteresis between the charge and discharge curves. In this work, we use electrochemical and structural analysis to elucidate the reasons for the degradation observed after deep desodiation of Na4MnV(PO4)3. X-ray diffraction analysis of the electrodes after cycling demonstrates that a phase transformation is initiated when the anodic potential limit exceeds 3.8 V, which results in the formation of distorted NASICON-type phases and gradual amorphization. X-ray absorption spectroscopy studies suggest that the observed detrimental phase transitions might be triggered by the changes in the local environment of oxidized vanadium, which destabilize the structure. We thus demonstrate that the degradation of the Na4MnV(PO4)3 material is of thermodynamic origin, with its consequences being reflected in a dramatically decreased de/intercalation rates and a rapid deterioration in the material performance.

High-rate capability of three-dimensional CNTs-decorated NaTi2(PO4)3@C microspheres for sodium energy storage

One of the newest materials for sodium energy storage is NaTi 2 (PO 4 ) 3 , which is widely researched due to its considerable Na + conductivity and excellent safety characteristics. However, NaTi 2 (PO 4 ) 3 exhibits unfavorable electronic conductivity, restricting its application in sodium-ion batteries. Herein, three-dimensional CNTs-modified NaTi 2 (PO 4 ) 3 @C microspheres were synthesized by spray-drying method and solid-state high-temperature annealing. Within the designed composite, the NaTi 2 (PO 4 ) 3 @C nanoparticles were uniformly fixed on the CNTs surfaces, forming a three-dimensional CNTs-NaTi 2 (PO 4 ) 3 @C architecture. As an anode in a sodium-ion battery, the resulting CNTs-NaTi 2 (PO 4 ) 3 @C exhibited exceptional sodium storage potential, with a high reversible capacity, stable cycling properties, and a good rate capability. An excellent discharge capacity of about 128.5 mAh g -1 was achieved with a low rate of 0.1C, and the anode displayed a reversible capability of 75.8 mAh g -1 at 20C over 1000 cycles, with a low capacity fading rate of about 0.011% per cycle. Therefore, this novel strategy is highly effective and can be adopted to enhance the battery properties of other electrode materials.

Green Synthesis of Zinc Sulfide-Reduced Graphene Oxide Composite and its Application in Sodium-Ion Batteries

Green Synthesis of Zinc Sulfide-Reduced Graphene Oxide Composite and its Application in Sodium-Ion Batteries

Structural engineering of bimetallic selenides for high-energy density sodium-ion half/full batteries.

The shortage of high-capacity anode materials with long cycling stability is the main roadblock to the development of sodium-ion batteries (SIBs). The advantages of transition metal selenides are high theoretical capacity, safety and ease of design, which gradually make them potential substitute materials for the anodes of a new generation of SIBs. However, the low intrinsic conductivity of transition metal selenides and the serious powderization during charge and discharge processes restrict their rate performance and cycling stability in SIBs. Herein, bimetallic selenide ZnSe/MoSe2@NC is fabricated by in situ selenation of a rhombic dodecahedron structured metal-organic framework (MOF) containing Zn/Mo salt. Such a heterojunction and structural regulation effectively promote sodium ion transportation. Furthermore, the porous and hierarchical ZnSe/MoSe2@NC is capable of adapting to the volume stress generated by sodium ion (de)insertion. Specifically, in SIB half-cell measurement, a comparable capacity of 401.8 mA h g-1 after 100 cycles at 1 A g-1 can be achieved by ZnSe/MoSe2@NC. Additionally, the ZnSe/MoSe2@NC polyhedron delivers a high capacity of 345.7 mA h g-1 at 5 A g-1 (1500 cycles). Electrochemical kinetics analysis is performed in detail. In SIB full battery applications, the cell shows an impressive energy density of 175.1 W h kg-1. This research broadens the development prospect of transition metal selenides as anodes in SIBs.

Effect of vanadium doping on the electrochemical performances of sodium titanate anode for sodium ion battery application.

In this study, V5+ doped sodium titanate nanorods were successfully synthesized by a sol-gel method with different optimized vanadium concentrations. Before testing as a promising anode material for sodium ion battery (SIB) application, the samples were systematically characterized. It was clearly observed that V5+ doping significantly affects the phase formation of sodium titanate samples and leads to the alteration of the major phase of Na2Ti3O7 to a single Na2Ti6O13 phase with increasing doping concentrations. Electrochemical investigations clearly showed that the optimized 15 wt% V5+ doped sample exhibits the highest capacity of 136 mA h g-1 at 100 mA g-1 after 900 cycles as well as better rate capability than the undoped sample by delivering 101 mA h g-1 capacity at a high current density of 1000 mA g-1. It is believed that the incorporation of highly charged V5+ in sodium titanate produces oxygen vacancies along with partial reduction of Ti4+ to Ti3+, resulting in improved electronic conductivity. The utilization of oxygen vacancies also preserves the integrity of the electrode, giving rise to long term cycling. Thereby, V5+ doping was found to be an effective strategy to enhance the electrochemical performance of the sodium titanate anode for SIBs.

O3-Type Na2/3Ni1/3Ti2/3O2 Layered Oxide as a Stable and High-Rate Anode Material for Sodium Storage

Sodium-ion batteries (SIBs) are currently the most promising candidates for large-scale energy storage devices owing to their low cost and abundant resources. Titanium-based layered oxides have attracted widespread attention as promising anode materials due to delivering a safe potential of about 0.7 V (vs Na+/Na) and a small volume contraction during cycles; P2-type Ti-based layered oxides are typically reported, due to the challenging synthesis of the O3-type counterpart resulting from the high percentage of unstable Ti3+. Herein, we report an anomalous O3-Na2/3Ni1/3Ti2/3O2 layered oxide as an ultrastable and high-rate anode material for SIBs. The anode material delivers a reversible capacity of 112 mA h g-1 after 300 cycles at 0.1 C, a good capacity retention rate of 91% after 1400 cycles at 2 C, and, in particular, a capacity of 52 mA h g-1 even at a high rate of 20 C (1780 mA g-1). Furthermore, the in situ X-ray diffraction monitoring reveals no phase transitions and almost zero strain both underlie the good long-cycle stability. The measured high apparent Na+ diffusion coefficient (2.06 × 10-10 cm2 s-1) and the low migration energy barrier (0.59 eV) from density functional theory calculations are responsible for the superior rate capability. Our results promise advanced high-performance O3-type Ti-based layered oxides as promising anode materials toward application for SIBs.

Hard Carbon Microsphere with Expanded Graphitic Interlayers Derived from a Highly Branched Polymer Network as Ultrahigh Performance Anode for Practical Sodium-Ion Batteries

Growing attention has been attached to hard carbon in sodium-ion batteries (SIBs). However, hard carbon from individual precursors tends to exhibit an inferior rate capability due to its limited interlayer distance. Here, a coupled strategy is designed to prepare hard carbon microspheres (HCMSs) via the pyrolysis of a highly branched polymer network formed instantaneously between two interactive precursors during the atomization of the spray drying process. The combined precursors with a tunable cross-linked structure prefer to generate a large interlayer spacing (0.399 nm) and abundant closed pore structure by suppressing the graphitization of precursors during the carbonization, relative to the individual precursor, which contributes greatly to the ion diffusion kinetics. Benefiting from the unique structure, HCMS exhibits an impressively high reversible specific capacity of 373.4 mA h g-1 in SIBs and high initial Coulombic efficiency of 88%, retaining 90.2% of the initial capacity even after 150 cycles, which presented comparable capacities with commercial graphite in lithium-ion batteries. Besides, excellent rate capability was also demonstrated with HCMSs (250 and 117 mA h g-1 at 300 and 600 mA g-1). Notably, the interlayer distance and closed pore structure are tunable just by adjusting the ratio of the two precursors. The tunable and extendable fabrication process, together with its amazing high carbon yield of 48 wt % (1400 °C) and high tap density close to 0.8 g cm-3, makes this strategy promising in the practical application for SIBs.

Manipulating the Phase Compositions of Na3(VO1-xPO4)2F1+2x (0 ≤ x ≤ 1) and Their Synergistic Effects with Reduced Graphene Oxide toward High-Rate Sodium-Ion Batteries.

Sodium-ion batteries (SIBs) have aroused intense research and academic interest due to the natural abundance and cost-effectiveness of sodium resources. Presently, cathode materials based on the Na3(VO1-xPO4)2F1+2x (0 ≤ x ≤ 1, NVPF1+2x) polyanionic framework show intriguing electrochemical performances toward practical and advanced SIBs due to its high operating voltage (>3.9 V) and high energy density (>500 Wh kg-1). Different from conventional approaches focusing on delicate morphology design, metal ion substitution, and the conductive matrix's incorporation to overcome the low intrinsic electrical conductivity, here we adopt a one-step microwave-assisted hydrothermal approach to optimize the electrochemical performances of NVPF1+2x via manipulating its phase compositions with different vanadium sources and distinguishing the tetragonal (I4/mmm) symmetry of the Na3(VOPO4)2F phase from the orthorhombic symmetry (Amam) of the Na3V2(PO4)2F3 phase. The introduction of the conductive reduced graphene oxide (rGO) framework and its impacts on the phase compositions were systematically investigated. The rGO framework with different calcination temperature can alter the phase composition and the electrical conductivity of NVPF1+2x cathodes significantly, thus having a great impact on their electrochemical performances. Galvanostatic charge/discharge, cyclic voltammetry, electrochemical impedance spectroscopy, and the galvanostatic intermittent titration technique are adopted to compare their electrode polarization and kinetics difference and show that NVPF@rGO-600 °C possesses a high rate, small polarization, and fast kinetics electrochemical properties. This work provides new insights into manipulating phase compositions of the NVPF1+2x cathode by modulating the synthesis conditions and revealing their synergistic effect with a rGO conductive framework toward a superior rate capability and more realistic practical applications for SIBs.

Ultrafast and Ultrastable Heteroarchitectured Porous Nanocube Anode Composed of CuS/FeS2 Embedded in Nitrogen-Doped Carbon for Use in Sodium-Ion Batteries.

The enhancement of the structural stability of conversion-based metal sulfides at high current densities remains a major challenge in realizing the practical application of sodium-ion batteries (SIBs). The instability of metal sulfides is caused by the large volume variation and sluggish reaction kinetics upon sodiation/desodiation. To overcome this, herein, a heterostructured nanocube anode composed of CuS/FeS2 embedded in nitrogen-doped carbon (CuS/FeS2 @NC) is synthesized. Size- and shape-controlled porous carbon nanocubes containing metallic nanoparticles are synthesized by the two-step pyrolysis of a bimetallic Prussian blue analog (PBA) precursor. The simple sulfurization-induced formation of highly conductive CuS along with FeS2 facilitates sodium-ion diffusion and enhances the redox reversibility upon cycling. The mesoporous carbon structure provides excellent electrolyte impregnation, efficient charge transport pathways, and good volume expansion buffering. The CuS/FeS2 @NC nanocube anode exhibits excellent sodium storage characteristics including high desodiation capacity (608 mAh g-1 at 0.2 A g-1 ), remarkable long-term cycle life (99.1% capacity retention after 300 cycles at 5 A g-1 ), and good rate capability up to 5 A g-1 . The simple, facile synthetic route combined with the rational design of bimetallic PBA nanostructures can be widely utilized in the development of conversion-based metal sulfides and other high-capacity anode materials for high-performance SIBs.

2D-2D MXene/ReS2 hybrid from Ti3C2Tx MXene conductive layers supporting ultrathin ReS2 nanosheets for superior sodium storage

Rhenium disulfide (ReS2) is a promising 2D-layered anode material for rechargeable batteries. However, this material suffers from severe agglomeration and volume expansion during ions insertion/extraction, leading to inferior battery performance. Building 3D hierarchical structure is an effective strategy to overcome these problems and simultaneously manifest synergistic effects. Herein, a one-pot hydrothermal method is introduced to construct N-doped carbon confined ReS2 ultrathin nanosheets anchored on few-layered Ti3C2Tx MXene substrate (MXene@ReS2@C). The MXene flakes can effectively reduce agglomeration of ReS2 nanosheets during charge/discharge process and generate chemical interaction with ReS2 nanosheets, thereby promoting charge transfer kinetic of hierarchical composite. Carbon incorporation not only stabilizes MXene from successive oxidation during hydrothermal procedure but also alleviates volume expansion of ReS2, ensuring cycling durability of electrode. When used as anode material of SIBs, this hierarchical MXene@ReS2@C hybrid with strong interfacial interactions demonstrates improved electrochemical performances with satisfying rate capability (138 mAh g−1 at 5.0 A g−1) and cycling stability (202 mAh g−1 at 2.0 A g−1 after 200 cycles). This work provides a new scope of synthesizing MXene-based transition metal sulfide composite for practical application in sodium ion batteries.

Validating the Structural (In)stability of P3- and P2-Na0.67Mg0.1Mn0.9O2-Layered Cathodes for Sodium-Ion Batteries: A Time-Decisive Approach.

In this study, magnesium-ion-substituted, sodium-deficient, P3- and P2-layered manganese oxide cathodes (Na0.67Mg0.1Mn0.9O2) were synthesized through a facile polyol-assisted combustion technique for applications in sodium-ion batteries. The electrochemical reaction pathways, structural integrity, and long cycling ability at low current rates of the P3- and P2-phases of the Na0.67Mg0.1Mn0.9O2 cathodes were investigated using time-consuming techniques, such as galvanostatic titration and series cyclic voltammetry. The results obtained from these techniques were supported by those obtained from operando X-ray diffraction (XRD) analysis. Particularly, the P2-phase provided excellent structural stability owing to its intrinsic crystal structure, thereby exhibiting a reversible capacity retention of 82.6% after 262 cycles at a low rate of 0.1 C; in contrast, the P3-phase exhibited a capacity retention of 38.7% after 241 cycles at a similar current rate. The air stability of these as-prepared powders, which were stored under ambient conditions, was progressively analyzed over a period of 6 months through XRD without conducting any special experiments. The results suggest that in the P3-phase, the formation of NaHCO3 and hydrated phase impurities, resulting from Na+/H+ exchange and hydration reactions, respectively, was likely to occur more quickly, that is, within a few days, compared to that in the P2-phase.

MXene/TiO2 Heterostructure-Decorated Hard Carbon with Stable Ti-O-C Bonding for Enhanced Sodium-Ion Storage.

Hard carbon (HC) has attracted considerable attention in the application of sodium-ion battery (SIB) anodes, but the poor realistic capacity and low rate performance severely hinder their practical application. Herein we report a solvent mechanochemical protocol for the in situ fabrication of the HC-MXene/TiO2 electrode by functionalizing MXene to improve the electrochemical performance of the batteries. MXene (Ti3C2Tx) with abundant oxygen-containing functional groups reacts with HC particles in the ball milling process to form a Ti-O-C covalent cross-linked HC-MXene composite, in which the edge of the MXene nanosheets is in situ oxidized by air to form TiO2 nanorods, forming a regular 1D/2D MXene/TiO2 heterojunction structure. Ti-O-C covalent bonding can protect the heterojunction structures from pulverization and detachment from the current collector during charge/discharge cycles due to sodium-ion intercalation/detachment, thus improving the stability of the electrode structure. Meanwhile, the MXene/TiO2 heterojunction can form a 3D conductive network and provide more active sites. The resulting HC-MXene/TiO2 electrode exhibits superior electrode capacity (660 mAh g-1), making it a promising anode material for SIBs. This simple and efficient method for preparing MXene/TiO2 heterojunction-decorated HC provides a new perspective on the structural design of MXene and carbon material composites for SIBs.

Hierarchical micro-composite assembled from Bi spheres and expanded graphite flakes as anodes for sodium-ion half/full cells with excellent comprehensive electrochemical performance

Developing anode materials with both excellent comprehensive electrochemical performance and low cost is critical for the large-scale practical application of sodium-ion batteries. Herein, a novel hierarchical micro-composite assembled from Bi nano/submicron spheres and expanded graphite flakes (labelled as H-BiS/EGF) is fabricated by facile and scalable methods, using low-cost starting materials. As anodes for sodium-ion half cells, the H-BiS/EGF micro-composite exhibits a first coulombic efficiency of 85% with a reversible capacity of around 288 mAh g−1 at 0.5 A g−1, outstanding cycle stability (95% capacity retention for 17,300 cycles at 5 A g−1) and superior rate capability (228 mAh g−1 at 25 A g−1). The sodium-ion full cell, which was constructed with the H-BiS/EGF anode and the synthesized C coated Na3V2(PO4)3/rGO as the cathode, delivers a high energy density (180 Wh kg−1 at 1C) and good cycle performance (95.9% capacity retention after 600 cycles at 10C).

Design of cross-welded Na3V2(PO4)3/C nanofibrous mats and their application in sodium-ion batteries

Design of cross-welded Na3V2(PO4)3/C nanofibrous mats and their application in sodium-ion batteries

Diaper-derived selenium–carbon composites as high-capacity anodes for sodium-ion batteries

Exploring ideal electrode materials and overcoming key issues such as large changes in electrode volume resulting from the big radius of Na ions and slow redox kinetics are urgent issues in the large-scale applications of sodium-ion batteries. Here, through freeze-drying and annealing strategies, a molecular complex of Se encapsulated in superabsorbent polymers carbon (Se@SAPC) has been constructed. The superabsorbent polymers carbon base serves as a storage space for the reaction of Se and Na+ and shows good physical constraints and can ensure the overall structural stability of a Se@SAPC composite anode. In addition, the hierarchical pore structure effectively can adjust the volume effect of Se, so that electrons and ions are transferred smoothly in the circulation. Electrochemical measurements showed that the Se@SAPC electrode show excellent performance, including a long cycle life (198 mA h g−1 after 1000 cycles at 2 A g−1), and high-rate performance (200 mAh g−1 at 5 A g−1). At the same time, in-situ Raman, ex-situ transmission electron microscopy and electrochemical analysis reveals the working principle of intercalation/deintercalation of Na ions in Se@SAPC composites. In addition, the full Se@SAPC // Na3V2(PO4)3/C battery shows a large reversible capacity of 198.4 mAh g−1 even after 200 cycles at 0.2 A g−1 current density. This work provides guidance for the further development and utilisation of Se anodes.