Materials For Sodium-ion Batteries Research Articles

Tuning Na Occupation and Annealing Temperature on Na Diffusion Pathways in P2-Type NaxNi0.25Mn0.75O2 for Sodium-Ion Batteries by Ab Initio Calculations.

The NaxNi0.25Mn0.75O2 cathode material draws ongoing interest owing to its considerable specific capacity along with its elevated average operating voltage. However, its application is limited by weak rate performance and quick capacity fading. In this study, a series of NaxNi0.25Mn0.75O2 (x = 0.65, 0.70, 0.75, 0.80) cathode materials are prepared by the solid-phase method based on an orthogonal experiment. The optimum preparation process is investigated by optimizing factors such as Na content, calcination temperature, calcination time, and heating rate. The Nae/Naf ratio is adjusted, and the Na+ at different sites are rearranged to reduce the Na+/vacancy ordering by changing the Na content on the basis of process optimization. Owing to the fast migration kinetics of Nae sites, experimental results indicate that the P2-Na0.75Ni0.25Mn0.75O2 cathode material, which has Na+ occupying more thermodynamically stable Nae sites, demonstrates superior battery performance. High initial discharge specific capacity (157.2 mAh g-1) along with favorable cycle performance of the Na0.75Ni0.25Mn0.75O2 cathode material can be achieved by modifying the Nae site occupancy and optimizing the experimental conditions. Together with the microscopic control of Na+ occupancy, this novel orthogonal experiment design offers a fresh perspective and approach to a thorough comprehension of cathode materials for sodium-ion batteries.

A phase transition coordinated monoclinic Fe-based Prussian blue for high-performance sodium-ion battery cathode

Prussian blue analogs (PBAs) are ideal cathode materials for sodium-ion batteries (SIBs) owing to their cost-effectiveness, good low-temperature performance, and facile synthesis process. Nevertheless, their actual capacity and cycling stability limit practical application. Herein, a new chelating agent, sodium tartrate, is proposed to synthesize high-quality Fe-based Prussian blue (HQ-NFF) with enhanced Na content and a stable structure through chelation effect-assisted co-precipitation. The crystal structure of HQ-NFF undergoes a phase transition to a Na-rich monoclinic phase after full discharge, leading to improved capacity and cycling stability. The HQ-NFF cathode exhibits an ultra-high capacity of 160.8 mAh g−1 and a capacity of 146.1 mAh g−1 at 2 C, with a capacity retention of 75.3 % after 150 cycles. Moreover, a 3D-printed HQ-NFF cathode with an areal loading of 7.88 mg cm−2, delivers a high areal capacity of 0.969 mAh cm−2 and good rate capability.

Manipulating Electrolyte Interface Chemistry Enables High-Performance TiO2 Anode for Sodium-Ion Batteries

Titanium dioxide (TiO2) has emerged as a candidate anode material for sodium-ion batteries (SIBs). However, their applications still face challenges of poor rate performance and low initial coulomb efficiency (ICE), which are induced by the unstable solid-electrolyte interface (SEI) and sluggish Na+ diffusion kinetics in conventional ester-based electrolytes. Herein, inspired by the electrode/electrolyte interfacial chemistry, tetrahydrofuran (THF) is exploited to construct an advanced electrolyte and reveal the relationship between the improved electrochemical performance and the derived SEI film on TiO2 anode. The robust and homogeneously distributed F-rich SEI film formed in THF electrolyte favors fast interfacial charge transfer dynamics and excellent interfacial stability. As a result, the THF electrolyte endows the TiO2 anode with greatly improved ICE (64.5%), exceptional rate capabilities (186 mAh g−1 at 5.0 A g−1), and remarkable cycling stability. This study elucidates the control of interfacial chemistry by rational electrolyte design and offers insights into the development of high-performance and long-lifetime TiO2 anode.

Pr6O11 modification effectively enhancing sodium storage for Na3V2(PO4)3 batteries

Na3V2(PO4)3 (NVP) is one of the most promising cathode materials for sodium-ion batteries (SIBs) due to its robust three-dimensional framework, high tunability, and relatively high Na+ intercalation potentials. However, its utility is generally constrained by low conductivity, inefficient charge transfer, and subpar interface kinetics. This work presents an efficient and simple method to address these issues. We innovatively modified the NVP surface with Pr6O11 nanoparticles, a negative temperature coefficient (NTC) thermosensitive material, to enhance interface compatibility with electrolytes and improve conductivity. This modification significantly enhances the overall sodium-ion storage performance. Specifically, the optimized NVP-2 %Pr6O11 electrode exhibits excellent electrochemical properties with the aid of an optimized conductivity network compared to the unmodified NVP. Cycled at an 8C current density, the NVP-2 %Pr6O11 electrode achieves high specific capacities of 102.6 mAh·g−1 at 27 °C and 95.6 mAh·g−1 at 45 °C. After 1000 cycles, the capacity retention rates are 81.18 % and 78.97 %, respectively, significantly higher than the 20.59 % and 14.99 % of pure NVP. In coin full-battery testing, the NVP-2 %Pr6O11 electrode retains 89.76 % capacity after 500 cycles at 8C. In addition, the assembled The NVP-2 %Pr6O11//HC pouch full battery exhibits better sodium-ion storage and thermal safety performance compared to the NVP-SP//HC battery. This simple modification strategy provides an effective insight into the application of NVP electrodes in energy storage.

Improving the Performance of the Layered Nickel Manganese Oxide Cathode of Sodium-Ion Batteries by Direct Coating with Sodium Niobium Oxide.

This research highlights the efficacy of NaNbO3 as a coating for P2-Na2/3Ni1/3Mn2/3O2 cathodes in sodium-ion batteries. The coating enhances the kinetic behavior and cyclability of the electrochemical cells, as shown by electrochemical measurements. XRD analysis indicates that Nb does not incorporate into the cathode structure, implying a physical interaction between the coating and the cathode material. XRF analysis and EDX mapping confirm the actual composition and uniform dispersion of elements throughout the sample, while the electron micrographs evidence the occurrence of NaNbO3 particles modifying the surface of the layered oxide. The Ni4+/Ni3+ and Ni3+/Ni2+ redox pairs, along with the partially reversible oxidation of oxide to peroxide anions, contribute significantly to cell capacity, as revealed by XPS spectra. This last effect and the appearance of a co-intercalated phase at high voltage are positive factors to provide fast kinetics. Cyclic voltammograms show that samples coated with 2-3% NaNbO3 have superior rate capability, with high capacitive response and apparent diffusion coefficients. These samples also have low impedance at the electrode-electrolyte interface, which helps deliver a high capacity at 5C. Further cycling at 1C shows improved cyclability in the bare and 3% coated samples, due to their higher diffusion coefficients on charging. Notably, the 3% NaNbO3-coated sample exhibits excellent cyclability below 0 °C, making it a promising cathode material for sodium-ion batteries.

Dual-Driven Ion/Electron Migration and Sodium Storage by In Situ Introduction of Copper Ions and a Carbon-Conductive Framework in a Tin-Based Sulfide Anode.

Tin sulfide (SnS) has emerged as a promising anode material for sodium ion batteries (SIBs) due to its high theoretical capacity and large interlayer spacing. However, several challenges, such as severe insufficient electrochemical reactivity, rapid capacity degradation, and poor rate performance, still hinder its application in SIBs. In this study, in situ introduction of copper ions and a carbon conductive framework to form SnS nanocrystals embedded in a Cu2SnS3 lamellar structure heterojunction composite (SnS/Cu2SnS3/RGO) with graphene as the supporting material is proposed to achieve dual-driven sodium ion/electron migration during the continuous electrochemical process. The designed structure facilitates the preferential electrochemical reduction of copper ions into copper nanocrystals during the discharge process and functions as a catalytically active center to promote multivalence tin sodiation reaction. Furthermore, during the charging process, the presence of copper nanocrystals also facilitates efficient desodiation of NaxSn and further activates to form higher valence state sulfides. As a result, the SnS/Cu2SnS3/RGO composite demonstrates high cycling stability with a high reversible capacity of 395 mAh g-1 at 5A g-1 after 500 cycles with a capacity retention of 85.6%. In addition, the assembled Na3V2(PO4)3∥SnS/Cu2SnS3/RGO sodium ion full cell achieves 93.7% capacity retention after 80 cycles at 0.5 A g-1.

Oxidized Ti3Al(1-x)SnxC2 MAX phases as negative electrode materials for sodium ion batteries

Materials proposed for the negative electrodes in sodium-ion batteries often include oxides capable of reacting with Na+ through intercalation, conversion, or alloying. While these oxides offer high specific capacities, they suffer from poor mechanical stability. A novel approach to address this issue involves designing tailored nanocomposites based on the (Ti/Sn)Ox system, achieved through partial oxidation of tin-containing MAX phase (Ti3Al(1-x)SnxC2, x = 0.4 and 0.7). By employing this strategy, we have developed composite electrodes based on Ti(1-y)SnyO2 and MAX phase, which exhibit remarkable durability, withstanding over 600 cycles in half-cells. These electrodes also demonstrate charge efficiencies higher than 99.8 % and specific capacities comparable to MXenes electrodes. These outstanding electrochemical performances are further validated at the full-cell level when combined with Na0.44MnO2 positive electrodes. The reaction mechanism between the composite and the sodium ion was also studied using in-situ techniques (Raman and XAS) and the contribution of the different components during sodiation and de-sodiation was highlighted.

Interface engineering-induced enhancements in sodium-ion batteries: A nexus of ZnS nanoparticles and reduced graphene oxide for augmented storage and conductivity

Due to the inherent sluggish kinetics and the pronounced volumetric expansion of zinc sulfide (ZnS), it has become a prevalent modification strategy to regulate its morphology and composite with graphene for using ZnS as anodes in sodium-ion batteries (SIBs). Nevertheless, the elucidation of mechanisms underpinning the electrochemical performance facilitated by graphene incorporation remains scant. To further describe the synergistic mechanism, the ultrafine ZnS nanoparticles anchored on reduced graphene oxide (rGO) were synthesized through a simple solvothermal method. Research shows that the ZSG (ZnS nanoparticles-reduced graphene oxide composite) electrode suggests superior rate capability, maintaining a reversible specific capacity of 228.6 mAh·g−1 upon returning from a high current density of 5 A·g−1. Furthermore, the nanoscale integration of ZnS particles with rGO synergistically mitigates the structural expansion of the ZSG electrode encountered during cycling, thereby decelerating the degradation of cyclic performance. Insights gleaned from first-principles calculations and comprehensive electrochemical evaluations reveal that the built-in electric field, engendered within the composite architecture, substantially augments charge transfer ability and mitigates the energy barriers impeding sodium ion (Na+) diffusion accordingly. Consequently, the methodology adopted for synthesis and the synergistic modification mechanism can proffer a reference for the design of advanced anode materials in SIBs.

Effective stress dissipation by multi-dimensional architecture engineering for ultrafast and ultralong sodium storage

Stress accumulation is a key factor leading to sodium storage performance deterioration for NiSe2-based anodes. Therefore, inhibiting the concentrated local stress during the sodiataion/desodiation process is crucial for acquiring stable NiSe2-based materials for sodium-ion batteries (SIBs). Herein, a stress dissipation strategy driven by architecture engineering is proposed, which can achieve ultrafast and ultralong sodium storage properties. Different from the conventional sphere-like or rod-like architecture, the three-dimensional (3D) flower-like NiSe2@C composite is delicately designed and assembled with one-dimensional nanorods and carbon framework. More importantly, the fundamental mechanism of improved structure stability is unveiled by simulations and experimental results simultaneously. It demonstrates that this designed multidimensional flower-like architecture with dispersed nanorods can balance the structural mismatch, avoid concentrated local strain, and relax the internal stress, mainly induced by the unavoidable volume variation during the repeated conversion processes. Moreover, it can provide more Na+-storage sites and multi-directional migration pathways, leading to a fast Na+-migration channel with boosted reaction kinetic. As expected, it delivers superior rate performance (441 mA h g−1 at 5.0 A g−1) and long cycling stability (563 mA h g−1 at 1.0 A g−1 over 1000 cycles) for SIBs. This work provides useful insights for designing high-performance conversion-based anode materials for SIBs.

N/P/O co-doped porous carbon derived from agroindustry waste of peanut shell for sodium-ion storage

Porous bio‑carbon from agroindustry waste behaves one of the most promising anode materials for sodium-ion batteries (SIBs) because of its high sodium storage capacity, low cost, sustainability, and low charge/discharge voltage platform. Herein, we have developed a new N/P/O co-doped porous hard carbon derived from peanut shell (PSCNP) synthesized via KOH activation, hydrothermal doping combined with carbonization method, using chitosan as nitrogen source, phytic acid as phosphorus source, and peanut shell as carbon and oxygen source. Through seriously regulating the calcination temperature, the optimal PSCNP-800 carbonization at 800 °C can well combine the advantages of the natural rich porous microstructure of peanut shells, large graphite interlayer spacing (0.379 nm), and short diffusion distance for sodium-ion. As an advanced anode for SIBs, the PSCNP-800 delivered a reversible capacity of 248.8 mAh g−1 after 100 cycles at 25 mA g−1. This work could provide a possible idea for the preparation of N/P/O co-doped porous hard carbon from low-cost agroindustry waste as anodes for SIBs.

Research Progress of Cobalt Based Phosphide Anode Materials for Sodium-Ion Batteries

Research Progress of Cobalt Based Phosphide Anode Materials for Sodium-Ion Batteries

Coal-based graphene derived from different coal ranks: exceptional sodium storage performance in sodium-ion batteries.

Coal is a premium carbon material precursor as anode materials for sodium-ion batteries (SIBs). Additionally, developing anode materials with large capacity and rapid charging performance is essential for the advancement of SIBs. Consequently, in this work, coal-based reduced graphene oxide (CrGO) was prepared as an anode materials for SIBs by a modified Hummers-high temperature thermal reduction method with different ranks of coal (coal-based graphite, CG) as a precursor. The CG prepared from higher-rank coal exhibits a higher degree of graphitization, and its graphene layers are easier to exfoliate. The unique microstructure of CrGO provides stability during the sodium storage process and exhibits fast ion capacitive adsorption behavior, enhancing reaction kinetics. CrGO, with an initial reversible capacity of up to 331 mA h g-1 at a current density of 0.03 A g-1, achieves a specific capacity of 75 mA h g-1, even at a high current density of 10 A g-1. Notably, CrGO also maintains a good specific capacity of 123 mA h g-1 after 1000 cycles at a current density of 1 A g-1, with a capacity retention rate of 91.8%. This study highlights the potential for using coal-derived materials in the development of high-performance anode materials for SIBs, promoting the green and high-value utilization of coal.

Optimization of sodium-ion battery cathode performance by nickel-based Prussian blue epitaxial growth with iron-based Prussian blue core-shell structure

To address the structural defects and poor electrical conductivity of conventional Prussian blue analogues (PBAs) samples, in this study, nickel hexacyanoferrate (NiHCF) and nickel hexacyanoferrate epitaxially grown with iron hexacyanoferrate (Ni@FeHCF-X) series of samples were successfully synthesized by co-precipitation combined with epitaxial growth technique, and their structural and electrochemical properties were systematically characterized. X-ray powder diffractometer (XRD) results show that all the samples maintain a cubic crystal system structure, and the diffraction peaks of the (220) and (400) crystal planes are shifted to a lower angle with the epitaxial growth of ferric hexacyanoferrate (FeHCF). The successful embedding of Fe was confirmed by inductively coupled plasma (ICP) measurement data. Scanning electron microscope (SEM) images show that the samples are in a cubic morphology, and the surfaces gradually become rounded from sharp to rounded with the increase of the Fe content. High-resolution transmission electron microscope (HRTEM) and energy-dispersive spectrometer (EDS) analyses confirm the successful construction of the core-shell structure and the homogeneous distribution of the elements. Electrochemical testing showed that the Ni@FeHCF-X samples exhibited higher specific capacities and superior rate performance compared to NiHCF, particularly the Ni@FeHCF-4 sample, which delivered a high specific capacity of 73.4 mAh·g⁻¹ at a current density of 100 mA·g⁻¹, significantly outperforming the 38.2 mAh·g⁻¹ achieved by NiHCF. Additionally, the capacity retention rate of Ni@FeHCF-4 reached 42.16 %. Electrochemical impedance spectroscopy (EIS) further confirmed the reduced charge transfer resistance and enhanced reversibility of the electrochemical reactions in the Ni@FeHCF-X samples. These results demonstrate that Ni@FeHCF-4 significantly enhances the electrochemical performance of the samples in aqueous sodium-ion battery, providing new insights into the design of cathode materials for sodium-ion batteries.

Scalable production and performance optimization of Na3V2(PO4)3 cathode materials for sodium-ion batteries

The Na3V2(PO4)3 (NVP) cathode materials have garnered significant attention for grid energy storage due to their high theoretical capacity, rate performance, and cyclic stability. However, challenges persist, including inadequate electronic and ionic conductivity. This study addresses these issues through a novel solution-spray drying process using soluble precursors to achieve homogeneous mixing at the atomic level. This method not only promotes the formation of pure-phase NVP but also reduces carbon content effectively. Optimized heat treatment further enhances specific capacity, achieving 114 mAh/g at 0.1C with a coulombic efficiency of 99 %. These results highlight a scalable approach to improve the commercial viability of sodium-ion batteries by enabling efficient production of high-performance NVP cathode composites.

High temperature induced abundant closed nanopores for hard carbon as high-performance sodium-ion batteries anodes

Hard carbon (HC) stands out as the preeminent anode material for sodium-ion batteries (SIBs) which are deployed in expansive energy storage infrastructures. Herein, the large enough graphene nanosheets interlayer and abundant nanopores with a diameter of ∼2.1 nm induced by adjusting the pyrolysis temperature in the thermosetting phenolic resin-derived hard carbon matrix to augment the performance of the sodium ion storage. The presence of sufficiently large carbon interlayers has been proven to provide active sites for reversible adsorption, enabling effective storage of sodium ions in the high-voltage slope region, while also promoting rapid Na+ transport. Meanwhile, forming abundant closed nanopores with larger sizes helps sodium ion storage in the low-voltage plateau region. In the optimized samples, the formation of sufficient long graphene nanosheets with a perfect crystal lattice, which further shrinks to form enclosed nanopores, effectively reduces defective sites and specific surface area. Additionally, the appropriate content of C-O and C=O functional groups contributes to an exceptional initial Coulombic efficiency (ICE) of up to 93%. Simultaneously, the optimized sample HC-1500 contributes to a remarkable plateau capacity of 294 mAh g-1 during the charging process (high reversible capacity of 403 mAh g-1 at 0.1 C). Moreover, based on the microstructure evolution and Na storage behavior of hard carbon, an “adsorption (27%) – filling (73%)” sodium storage mechanism that the sodium storage as a quasi-metallic sodium state is demonstrated. Consequently, this study will offer valuable insights for the development of hard carbon anodes tailored for high-energy practical SIBs, while also advancing the understanding of sodium storage mechanisms.

Sulfur and Nitrogen Codoped Hard Carbon with Expanded Interlayer Distance as an Effective Anode Material for Sodium-Ion Batteries

Sulfur and Nitrogen Codoped Hard Carbon with Expanded Interlayer Distance as an Effective Anode Material for Sodium-Ion Batteries

Construction of honeycomb-like N-doped porous carbon framework with effective aperture distribution toward advanced supercapacitors and sodium-ion batteries

Smart synthesis of porous carbon with appropriate aperture distribution and high area utilization still retains an enormous challenge for efficient charge storage. Herein, a simple freeze-drying along with subsequent one-step carbonization/activation process is ingeniously devised to fabricate honeycomb-like nitrogen-doped porous carbon (NPC) framework with high-level active N/O-functional groups and hierarchical porous structure including substantial ultra-micropores (<0.7 nm). The underlying formation mechanism of such porous NPC framework is tentatively proposed. By finely regulating the dosage of NaHCO3, the optimized NPC (i.e., NPC114) is endowed with ultra-high surface area utilization of ∼26.4 μF cm−2 at 1 A/g in KOH electrolyte, which is close to theoretical value of electrochemical double-layer capacitance (15–25 μF cm−2), and even larger than the case (∼22.4 μF cm−2) with H2SO4 electrolyte due to the inaccessible ultra-micropores by SO42− of larger size. Similarly, as for the organic system, the as-prepared NPC115 with higher meso- and macropore surface area exhibits higher energy density of 22.36 Wh kg−1 than other counterparts. Furthermore, NPC114, when evaluated as anode material for sodium-ion batteries, exhibited more attractive high-rate Na+-storage properties as well. The in-depth understanding into intrinsic relationship between aperture distribution and electrochemical behaviors will provide meaningful guidance for electrode material design

Structure-directing agent mediated synthesis of SnS2 coupled with UltrapheneTM as highly stable anode material for sodium-ion battery

Sodium-ion battery (SIB) with abundant resources has been intensively developed as the efficient energy storage device. Tin disulfide (SnS2) is one of the attractive anode materials due to its high capacity and two-dimensional structure. Nevertheless, volume expansion and low conductivity result in the poor rate performance and stability. In this study, three strategies are applied to design efficient SnS2-based anode materials for the SIB. Two precursor solvents of deionized water (DIW) and ethanol and one structure-directing agent of cetyltrimethylammonium bromide (CTAB) are incorporated to synthesize SnS2. The commercial UlrapheneTM is further mixed with SnS2 to design composites (U/s-SnS2) with different ratios. The optimal SnS2 and U/s-SnS2 anodes respectively show the specific capacities of 187.7 and 326.3 mAh/g at 1.6 A/g. After 100 cycles, the U/s-SnS2 anode still attains specific capacities of 308.7 and 438.9 mAh/g at 1.0 and 0.1 A/g corresponding to capacity retentions of 74.5 % and 80.1 %, respectively. The excellent rate performance and cycling stability of the U/s-SnS2 anode are attributed to the smaller charge-transfer resistance and the larger Na+ diffusion coefficient. This work successfully brings a blueprint for adopting several useful strategies to improve the electrochemical performance of SnS2. The effects for all parameters are also carefully explained.

Elevating electrochemical performance of Na4MnCr(PO4)3 cathode material for sodium ion batteries through the synergistic effect of Sc doping and RuO2/C coating

The widespread interest in Na4MnCr(PO4)3 (NMCP) for sodium-ion batteries (SIBs) derives from its high energy density and earth abundance. Nevertheless, the poor rate capability and unsatisfactory cycle performance restrict the application of NMCP cathodes in commercialized SIBs. Herein, we designed and prepared the dual-modified NMCP cathode materials by combining doping Sc3+ and hybrid coating with RuO2/C. Benefiting from the synergistic effects of two approaches, the structural stability and the Na+ diffusion as well as the electronic conductivity have been elevated synchronously. Therefore, the optimized Na4MnCr0.95Sc0.05(PO4)3@RuO2/C composite (NMCSP@RC) presents a superior rate capability (163.4 mAh/g at 50 mA g−1 and 87.6 mAh/g at 1000 mA g−1) and extended cycle stability (capacity retention of 66.3 % after 500 cycles at 1000 mA g−1) compared to pure NMCP. Moreover, a full SIB cell with NMCSP@RC cathode demonstrates a praiseworthy energy density of 469.8 Wh kg−1. This study proves the effectiveness of the dual modification strategy on NMCP, which could provide a fresh idea to optimizing the performance for NMCP cathode materials and contribute to the final fulfillment of their commercialized application.

Nanoarchitectured Fe3C@N-Doped C/FeVO4 as High-Performance Anode for Sodium-Ion Batteries.

Ferric vanadate exhibits potential as an attractive anode material for sodium-ion batteries (SIBs) due to the multiple oxidation states of vanadium and natural abundances of iron. However, the design and fabrication of high-performance ferric vanadate-based SIB anode materials with unique composite nanostructures are still challenging. Herein, a facile self-template method is reported to synthesize 1D nanostructured Fe3C@N-doped C/FeVO4 (Fe3C@NC/FeVO4) anode materials by the combination of morphology regulation with hybrid composite construction, for the first time. To this end, a 1D Fe, N-doped carbon nanotube (FeNC) is used as a template, followed by etching and re-growth to obtain the 1D Fe3C@N-doped C/FeVO4 nanostructure. The introduction of Fe3C can improve its electronic conductivity and enhance capacitive behavior. Additionally, the 1D nanostructure can effectively shorten the ions transport path and alleviate volume expansion during the charge-discharge processes. With these advantages, the SIBs using such anodes show a remarkable rate performance with a capacity of 325.4mAhg-1 at 0.1Ag-1, 150.6mAhg-1 at 5Ag-1, and excellent cycling stability with a reversible capacity of 139.6mAhg-1 at 1Ag-1 after 1500 cycles. This work offers a new strategy for the future development of SIBs with ferric vanadate-based anode.