Application In Sodium-ion Batteries Research Articles

Scalable fabrication of antimony nanoparticles confined in a porous carbon framework for high-performance sodium-ion batteries

Engineering of carbon/metal nanocomposites with small metal particles is promising for the development of alloy-type anodes. Herein, an [email protected] composite was developed from a commercial potassium antimony tartrate precursor using a scalable pyrolysis method. Ultrafine Sb nanoparticles are confined within a porous carbon framework, which substantially facilitates the diffusion of Na-ion/electrons and effectively alleviates the charging/discharging induced volume change. The obtained [email protected] material displays excellent electrochemical performance for Na+ storage. The Na+ diffusion behavior of [email protected] was comprehensively investigated using various methods, and its gas evolution during the discharge/charge was monitored via online mass spectrometry. Then, [email protected] was assembled into full cells. During discharge/charge processes, the Na3V2(PO4)2F3/[email protected] full cells delivered a competitive working voltage of 2.95 V and a capacity retention of 93.4% (50 cycles @ 0.2 A g−1). Considering its facile preparation method from a commercial precursor, the [email protected] composite can potentially realize a large-scale application of sodium-ion batteries.

Interlayer gap widened TiS2 for highly efficient sodium-ion storage

As an alternative for lithium-ion batteries (LIBs), sodium-ion batteries (SIBs) have lately received tremendous interest due to their abundant reserves as well as low cost. Nevertheless, the lack of suitable anode materials severely hinders the application of sodium-ion batteries. TiS2 is elected as a representative material owing to its unique layered structure. But it always suffers from capacity fade due to poor electrochemical kinetics and structural stability. In this work, we fabricate a pre-potassiated TiS2 as a host material for sodium storage by an electrochemical pre-potassiation strategy. The intercalation/extraction mechanism, structural changes and reaction kinetics are completely investigated to reveal the outstanding electrochemical property of pre-potassiated TiS2 electrode. It turns out that the large interlayer space of pre-potassiated TiS2 is conducive to the diffusion of sodium ions, inducing the reduction of entropic barrier for the electrochemical reactions. In addition, the pre-potassiated host structure is still firmly maintained upon repeated cycles. Therefore, the pre-potassiated TiS2 presents superior rate capability (165.9 mA h g − 1 at 1 C and 132.1 mA h g − 1 at 20 C) and long-term cycling stability (85.3% capacity retention at 5 C after 500 cycles) for SIBs. This research provides an avenue to construct long-life sodium energy storage systems based on pre-potassiated TiS2.

All-climate and air-stable NASICON-Na2TiV(PO4)3 cathode with three-electron reaction toward high-performance sodium-ion batteries

• The three-electron Na 2 TiV(PO 4 ) 3 delivers 187 mA h g −1 . • NTVP/C-G demonstrates ideal all-climate and air-stable performances. • In-situ XRD shows that NTVP involves Δ volume of 4.9%. • DFT calculations reveal low band gap and low energy barrier of 0.2 eV in NTVP. Developing all-climate and air-stable cathode with multi-electron redox reaction is intriguing and challenging for sodium-ion batteries (SIBs). Herein, we synthesize a NASICON (Na super-ionic conductor)-type Na 2 TiV(PO 4 ) 3 with an elaborately-engineered architecture, which shows ultrastable (1000 cycles at 40C) and ultrafast (up to 40C) three-sodium storage performances with an ultrahigh capacity of 187 mA h g −1 (equals to theoretical value) at 0.1C. Also, it displays good air-stability and high/low-temperature properties. A series of stepwise solid-solution, two-phase, solid-solution and two-phase mechanisms are involved and a small volume change of 4.9% is identified according to the operando X-ray diffraction results. Ex situ X-ray photoelectron spectroscopy reveals that V 4+ /V 3+ , Ti 4+ /Ti 3+ and V 3+ /V 2+ redox reactions are accompanied with three-sodium storage processes. The small band gap of 1.48 eV and fast 3D Na + diffusion pathways with low energy barrier of 0.2 eV calculated through first-principles calculations are responsible for the superior electrochemical performances. Our work prepares Na 2 TiV(PO 4 ) 3 with three-electron redox and high performance for future practical SIBs applications.

Engineering surface oxygenated functionalities on commercial hard carbon toward superior sodium storage

Hard carbon is the most promising anode material for sodium-ion batteries (SIBs). However, the poor rate capability and low reversible capacity are still big challenges for its wide commerical application in SIBs. However, there are two main barriers before large-scale industrialization, i.e., low reversible capacity and poor rate performance. In this work, we report a novel method enhancing commercial hard carbon anode through a facile chemical treatment. Commercial hard carbon with an expanded carbon interlayer is realized via controllably introducing oxygen functional groups. When employed as anode for SIB, the modified CHC demonstrates a high reversible capacity of 341 mAh g−1 at 20 mA g−1, which is much higher than pristine HC (270 mAh g−1). Excellent rate capability with a capacity of 50 mAh g−1 is maintained at 5000 mA g−1. More importantly, this facile oxidation strategy is also suitable for commercial soft carbon, which also displays significantly enhanced electrochemical performance. The kinetic measurements and theoretical calculation results reveal that the enhanced electrochemical properties should be attributed to the introduced oxygen function groups, which not only facilitate the diffusion of Na ions via enlarging the carbon interlayer distance, but also enhance the absorption capacity to Na ions.

Chemical intercalation of graphite using chromium trioxide for the anode application in rechargeable sodium-ion batteries

The Ceylon Journal of Science is published by the University of Peradeniya, Sri Lanka. Full text available. The journal also has its own website. The Ceylon Journal of Science is a continuation of the Ceylon Journal of Science (Biological Sciences) which is no longer being published as a separate journal. The history of the journal can be found here.From May 2020, Ceylon Journal of Science is indexed in DOAJ.

Effects of Salt Concentration on the Water and Ion Self-Diffusion Coefficients of a Model Aqueous Sodium-Ion Battery Electrolyte.

The aqueous sodium-ion battery is a promising alternative to the well-known lithium-ion battery owing to the large abundance of sodium ion resources. Although it is safer than the lithium-ion battery, the voltage window of the sodium-ion battery is narrower than that of the lithium-ion battery, thus limiting its practical implementation. Therefore, a highly concentrated electrolyte is required to address this issue. In the present work, the effect of the salt concentration on the transport properties of water molecules is investigated via theoretical analyses at the quantum mechanical level. A molecular dynamics simulation at the quantum mechanical level revealed that as the salt concentration increases, the ion-water interactions became stronger, leading to a lower diffusivity and a lower electronic band gap. These imply that the superconcentrated aqueous-based electrolytes have high potentials for the sodium-ion battery applications.

Suppressing O3−O’3 phase transition in NaCrO2 cathode enabling high rate capability for sodium-ion batteries by Sb substitution

Poor rate capability of cathode materials for sodium-ion batteries (SIBs) is one of the major obstacles hindering practical application of SIBs due to the large ion radius of Na+ and its sluggish kinetics. Improving rate capability for SIBs is a critical issue. Herein, we reveal that introducing small amount of Sb into O3-NaCrO2 can improve the rate capability of NaCrO2 cathode significantly. The occupation of Sb in Cr sites can expand the c/a ratio and the unit cell volume, thus promoting sodium diffusion in the a-b channels. Under a high rate of 5C, the 5% Sb-substituted Na0.9Cr0.95Sb0.05O2 (NCS-0.05) shows a reversible capacity of 114 mAh g−1 with capacity retention of 70.9% after 1000 cycles. Under an ultrahigh current rate of 32C, a reversible capacity of 96.1 mAh g−1 can still be maintained. Synchrotron in situ X-ray diffraction results reveals highly reversible phase transition behavior of NCS-0.05 during cycling even under high rates, and the O3 → O’3 phase transition in NaCrO2 is suppressed effectively by Sb substitution. Density functional theory calculations indicate that Sb substitution can also lower desodiation energy and decrease the bandgap of NaCrO2, leading to improved reaction kinetics and electronic conductivity.

Dual anion-doped porous carbon embraced TiO2 nanocrystals with long-term cycling performance for sodium ion batteries

TiO2 as one of critical anode materials for sodium ion batteries (SIBs) has excellent characteristics such as low cost, high safety, small volume expansion and high packing density. However, low conductivity and poor sodium ion diffusion ability prevent its further applications in SIBs. Thus, achieving functionalized carbon embraced TiO2 nanocrystals (NCs) becomes an alternative to boost the TiO2 performance in SIBs. Herein, using NH2-MIL-125 (Ti) and sulfur powder as template and sulfur source, N, S dual-anion doped porous carbon embraced ultrafine TiO2 NCs (TiO2@NSPC) are successfully constructed. Due to a large surface-to-volume ratio of TiO2 NCs, the transport pathway of sodium ions is greatly shortened. Meanwhile, N, S dual-anion doped porous carbon can ameliorate the electrical conductivity and transport efficiency of ions, effectively inhibiting the agglomeration of TiO2 NCs. As a result, when used as the anode of SIBs, TiO2@NSPC shows a reversible capacity of 230.2 mAh g-1 after 300 cycles at a current density of 500 mA g-1, with high capacity retention of 88.9%. Moreover, it exhibits extremely high cycling stability with a capacity of 63 mAh g-1 even at 10 A g-1 after 20000 cycles, and higher pseudocapacitive sodium storage than single heteroatom doping, causing its superior sodium ion storage capability. This strategy opens up a new situation to design new electrode materials with enhanced pseudocapacitance and superior sodium storage.

Organic/inorganic anions coupling enabled reversible high-valent redox in vanadium-based polyanionic compound

Recently, there has been a drive to design and develop mixed polyanion compounds for positive electrode applications in sodium-ion batteries (SIBs) due to their high-valent redox, robust electrode framework and good safety. Although advances have been made, the exploration of new electrode materials and fundamental understanding of working mechanisms have been lacking. Here, we report a low-temperature synthesis of an organic/inorganic anions coupled Na2(VO)2(HPO4)2(C2O4) polyanionic compound (noted as NVPC), which exhibits a distinctive layered structure. The structure is able to stabilize reversible high-valent redox of V4+/5+, thereby the NVPC shows a moderate reversible capacity of 105 mA h g−1 at 0.1 C and a high redox potential around 4.00/3.80 V vs. Na/Na+, which is larger than the NaVOPO4. The enhanced Na+ diffusion capability and reduced band gap in NVPC is experimentally demonstrated by galvanostatic intermittent titration technique and theoretically validated by calculations. Besides, a small volume change (1.36%) of NVPC electrode during intercalation reaction is unambiguously demonstrated by diffraction and nanoscale structural analysis. Generally, our studies highlight that coupling organic/inorganic anions in polyanionic compounds is a practical strategy to stabilize high-valent redox center for developing high energy density SIB cathode materials.

Novel Gel-Polymer Electrolytes for Sodium-Ion Secondary Batteries - An Electrochemical Impedance Spectroscopic Studies

Global lithium deposits have been consumed a lot because of the heavy usage of lithium-ion batteries (LIBs) in almost all portable electronic devices and in automobiles. Due to the very limited global lithium resources, the so-called ‘batteries beyond lithium-ion’ such as sodium-ion batteries (SIBs) are becoming popular, particularly in the R&D level. One of the common problems in the commercial level production of SIBs is the synthesis of suitable electrolytes with sufficient ambient temperature ionic conductivities. In this work, a set of novel gel-polymer electrolytes (GPEs) based on poly (methyl methacrylate) (PMMA) host polymer have been synthesized and characterized by electrochemical impedance spectroscopic (EIS), DC polarization and cyclic voltammetric (CV) techniques. The optimized PMMA-NaClO4-EC-DMC GPE composition (10:14:38:38 wt.%) showed an ambient temperature ionic conductivity of 8.4 mS cm-1. Ionic conductivity vs inverse temperature showed Arrhenius behavior with almost same activation energies of 0.16 eV for all the compositions studied. DC polarization test on SS/GPE/SS configuration showed that the best conducting composition is dominantly an ionic conductor (tion ~ 0.998) with negligible electronic conductivity, which is highly desirable to avoid short circuits within the cell. The CV test on best conducting composition revealed that the electrochemical stability window (ESW) of these GPEs is about 4 volts (- 2 to + 2 volts). This optimized composition with highest ambient temperature ionic conductivity and negligible electronic conductivity seems to be a promising candidate for practical applications in sodium-ion secondary batteries.

Ultrafine Sb2S3@carbon-nanofibers for fast and stable sodium storage

Sb2S3 has great theoretical capacity (946 mAh g−1), suitable working potential, and relatively low cost, and it has attracted attention as a potential anode material for sodium-ion batteries. However, the tardy diffusion of sodium ions and significant volume expansion hinder their practical application in sodium ion batteries. In this study, we encapsulated Sb2S3 nanoparticles in porous carbon nanofibers (CNFs) using electrospinning and gas vulcanization. The unique porous fiber structure and ultrafine Sb2S3 nanoparticles effectively improved diffusion speed and volume expansion of sodium ions, and they showed fast sodium-ion storage capacity and excellent cycle stability. The Sb2S3@CNFs used as the anode of a sodium-ion battery exhibited a remarkably reversible specific capacity of 151.3 mAh g−1 at 10 A g−1 for 500 cycles. A full cell assembled with Sb2S3@CNFs and Na3V2(PO4)3 (NVP) showed a reversible specific capacity of 283 mAh g−1 at 0.2 A g−1 after 100 cycles. Therefore, Sb2S3@CNFs has an excellent practical application in sodium-ion batteries owing to its simple synthesis method, excellent electrochemical performance, and suitable reaction potential.

Nitrogen and sulfur co-doped hierarchically mesoporous carbon derived from biomass as high-performance anode materials for superior sodium storage

A green, resource-abundant, economical, and reversible anode is essential in the large-scale energy storage application of sodium-ion batteries (SIBs). In this study, sulfur and nitrogen co-doped hierarchically porous carbon materials (SN–HPCS) have been synthesized using high-yield biomass starch as a precursor through a simple and repeatable structural design method. The SN–HPCS has a unique sponge-like porous morphology with a three-dimensional (3D) interconnected reticular structure, which creates space for the electrolyte penetration into the carbon network and facilitates charge transfer. Meawhile, heteroatom-doping not only expands the interlayer distances of carbon but also introducts defect into carbon, which provide more active sites for the storage of Na+. As an anode for SIBs, SN–HPCS exhibits a high capacity 313 mAh g−1 at 0.8 A g−1, a good rate performance 268 mAh g−1 at 2 A g−1, and outstanding cycling stability 156 mAh g−1 after 3000 cycles at a current density of 8 A g−1, while maintaining 93% of their initial capacity. The enhanced Na+ storage performance is attributed to the synergistic effect of the structure advantages and dual-doping of nitrogen and sulfur.

Biomass hard carbon of high initial coulombic efficiency for sodium-ion batteries: Preparation and application

Biomass hard carbon anodes have attracted wide attention due to the advantage of low cost and renewability, but the low initial coulombic efficiency (ICE) limits their practical application in sodium-ion batteries (SIBs). In this work, a carbonization method with low heating rate was conducted to prepare biomass hard carbon materials from camphor wood residues and explore the key factors that influence the ICE. As the heating rate decreases, the as-prepared biomass hard carbon with a relatively low amount of defects displays a high ICE of 82.8% by decreasing the initial irreversible capacity loss. Specifically, when the heating rate decreases to 0.25 ℃ min−1, the obtained hard carbon exhibits the optimal electrochemical performance with the initial charge capacity of 324.6 mAh g−1 and excellent cycle stability (90.0% capacity retention after 200 cycles at 50 mA g−1). Besides, matched with Na3V2(PO4)/C cathode, the full cell exhibits a high energy density of 245.3 Wh kg−1 and stable cycling performance. This comprehensive study provides a feasible method and opens new opportunities for biomass hard carbon, and extends the strategy to design the high-performance anode materials for SIBs.

Two-dimensional NbSSe as anode material for low-temperature sodium-ion batteries

Sodium ion batteries performance at low temperature is extremely restricted by the sluggish kinetics of sodium ions diffusion within active materials and interface. The strategy of inducing interlayer anionic ligands in two-dimensional NbSSe nanoplates is employed to consolidate the interlayer band gap and optimize the electronic structure. It combines complementary benefits from two kinds of anionic ligands with high conductivity and good affinity with sodium ions at low temperature. The explored two-dimensional NbSSe nanoplates can provide an acceptable rate and lifespan electrochemical performance, delivering a high reversible capacity of 136 mAh g−1 at 0 °C with the 92.67% retention after 500 cycles at 0.2 C. The totally sodium storage capacity are contributed from the combination of capacitive and diffusion behaviours. The sodium ion diffusion coefficients are in the range of 3.23 × 10-13 to 4.47 × 10-12 at 0 °C. The diffusion apparent activation energy is 54.92 kJ mol−1 and the activation energy is 65.97 kJ mol−1. The explored two-dimensional NbSSe nanoplates can extend the sodium ion battery application field, particularly at low temperatures.

Exploration of a Na3V2(PO4)3/C –Pb full cell Na-ion prototype

Recent research focusses typically on sodium-ion half cells, and the progress of high performance and cost-effective full cells remains a critical obstacle to commercialize sodium-ion batteries. Here, we rationally design a full sodium-ion battery based on carbon coated Na3V2(PO4)3 (NVP-C) cathode and Pb anode materials. Carbon coated NVP is prepared via easy and one-step solid-state method. With 8 wt% carbon content, the obtained NVP-C core-shell structure provides an excellent reversible capacity of 104 mAh/g at C/10 rate, approaching towards its theoretical capacity. The NVP-C electrode even at a high 5 C rate delivers a primary reversible capacity of 87 mAh/g with 99.9% capacity retention almost after 3500 cycles. As an anode, Pb delivers an initial reversible capacity of 477 mAh/g at a fixed current density of 13 mA/g with a good cyclability and capacity retention of 98.5% over 50 cycles. The full cell constructed from the as-prepared materials exhibits a preliminary reversible capacity of 233 mAh/g at C/10 rate. In addition, the good rate capability including discharge energy density in the range of 170–180 Wh/kg makes the full cell a potential candidate in practical sodium-ion battery application. The excellent electrochemical behavior with simple, low-cost properties of fabricated full cell mark it as attractive option for high-energy energy storage applications.

Origin of Air-Stability for Transition Metal Oxide Cathodes in Sodium-Ion Batteries.

The air-sensitivity of transition metal oxide cathode materials (NaxTMO2, TM: transition metal) is a challenge for their practical application in sodium-ion batteries for large-scale energy storage. However, the deterioration mechanism of NaxTMO2 under ambient air is unclear, which hinders the precise design of air-stable NaxTMO2. Here, we revealed the origin of NaxTMO2 degradation by capturing the initial degradation status and microstructural evolution under ambient atmospheres with optimal humidity. It was found that the insertion of CO2 into Na layers along (003) planes of NaxTMO2 led to initial growth of Na2CO3 nanoseeds between TM layers, which initiated fast structure degradation with surface cracks and extrusion of Na2CO3 out of NaxTMO2. The degradation extents and pathways for NaxTMO2 could be highly associated with crystal orientation, particle morphology, and ambient humidity. Interestingly, the deteriorated NaxTMO2 could be completely healed through optimal recalcination, showing even improved air-stability and electrochemical performance. This work provides a helpful perspective on the interfacical structure design of high-performance NaxTMO2 cathodes for sodium-ion batteries.

Surface organic nitrogen-doping disordered biomass carbon materials with superior cycle stability in the sodium-ion batteries

To achieve widespread application of sodium-ion batteries (SIBs) in the future new energy market, developing electrode materials with low-cost sustainability and excellent electrochemical properties is imperative. Herein, a mesoporous N-doping palm leaf-based hard carbon (PLHC-N) anode with a high-rate and long lifespan is synthesized via an in-situ polymerization method by using palm leaf as the carbon precursor and polyaniline as the nitrogen source. Benefiting from the natural holey structure, the PLHC-N exhibits excellent Na+ storage capability with numerous ion transfer channels and a good volume buffer. Meanwhile, the N-doping materials improve ion and electron transferability and create more active sites for Na storage. Impressively, the PLHC-N sample shows an adsorption-intercalation-hole filling storage mechanism and affords an ultrahigh reversible capacity of 373 mAh g−1 at 25 mA g−1, and long-term cycle stability at 200 mA g−1 (∼95.0% retention upon 1000 cycles). Moreover, a full cell with a Na3V2(PO4)2F3 as cathode shows a favorable cyclability (112 mA h g−1 after 100 cycles at 0.5C (1C = 128 mA g−1) and a decent capacity retention of 90.1%). Given the cost effectiveness and material sustainability, our work provides novel strategy to design the hard carbon anode materials for advanced SIBs.

Triggering anionic redox activity in Fe/Mn-based layered oxide for high-performance sodium-ion batteries

Among various sodium-ion cathode materials, Fe/Mn-based layered oxides stand out due to cost-effectiveness and relatively high theoretical specific capacity. However, further enhancement in capacity and improvement in cyclability are still needed to meet the requirements for practical applications in sodium-ion batteries. Herein, we report that ruthenium-doped Na0.67Fe0.5Mn0.5O2 can not only achieve high reversible capacity but also deliver superior cycling stability. Owing to the substitution of 4d ruthenium heteroatoms, the cathode exhibits promising electrochemical performance with a higher reversible specific capacity of 170 mA h g−1 at 0.2C between 2 and 4 V as well as a stable cycling performance with 82.2% capacity retention at 2C after 100 cycles compared to its pristine counterpart. Advanced structural characterization techniques combined with theoretical calculations unveil that the presence of ruthenium ions can trigger anionic redox activity, thus leading to harvesting of extra capacity. Moreover, ruthenium ions can also play an important role in stabilizing and improving the structural framework, resulting in prominent cyclability and excellent rate performance. Overall, the present work demonstrates that anionic redox activity could be triggered by integration of trace 4d element in Fe/Mn-based layered oxides and represents an effective strategy to develop high-performance sodium cathodes.

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.