High-performance Sodium-ion Storage Research Articles

SnO2–SnS2/graphene heterojunction composite promotes high-performance sodium ion storage

The design of electrode material nanostructures including reducing material sizes and designing appropriate heterostructures, has great potential in improving charge storage dynamics and enhancing practical performance. In this study, we present the innovative synthesis of SnO2-SnS2/graphene heterojunction composite materials via a controlled vulcanization reaction process. The unique structure endows the composite with high electronic conductivity, rapid ion diffusion rates, elevated electrochemical activity, excellent structural stability, and abundant reaction sites, making it a highly efficient anode material for sodium-ion batteries (SIBs). Half-cell tests demonstrate that the SnO2–SnS2/r–G composite achieves a first Coulombic efficiency of 77.3% at a high current density of 5 A/g, showing remarkable cycling stability. Remarkably, the composite retains a reversible capacity of 330 mA·h/g after 1000 cycles, with a capacity retention rate of 77.5%. Moreover, we elucidate the specific sodium storage mechanisms of the heterojunction composite electrode via in-situ and ex-situ characterization methods. Furthermore, a full battery utilizing Na0.53MnO2 as the cathode and SnO2–SnS2/r–G composite as the anode exhibits outstanding rate performance and long-term cycling stability. This method of heterostructure design and fabrication, coupled with the exceptional performance metrics, suggests that the SnO2–SnS2/r–G heterostructure is a promising candidate for advanced anode materials in SIBs applications.

Regulating the Pore Structure of Activated Carbon by Pitch for High-Performance Sodium-Ion Storage.

The pore structure of carbon anodes plays a crucial role in enhancing the sodium storage capacity. Designing more confined pores in carbon anodes is accepted as an effective strategy. However, current design strategies for confined pores in carbon anodes fail to achieve both high capacity and initial Coulombic efficiency (ICE) simultaneously. Herein, we develop a strategy for utilizing the repeated impregnation and precarbonization method of liquid pitch to regulate the pore structure of the activated carbon (AC) material. Driven by capillary coalescence, the pitch is impregnated into the pores of AC, which reduces the specific surface area of the material. During the carbonization process, numerous pores with diameters less than 1 nm are formed, resulting in a high capacity and improved ICE of the carbon anode. Moreover, the ordered carbon layers derived from the liquid pitch also enhance the electrical conductivity, thereby improving the rate capability of as-obtained carbon anodes. This enables the fabricated material (XA-4T-1300) to have a high ICE of 91.1% and a capacity of 383.0 mA h g-1 at 30 mA g-1. The capacity retention is 95.5% after 300 cycles at 1 A g-1. This study proposes a practical approach to adjust the microcrystalline and pore structures to enhance the performance of sodium-ion storage in materials.

A Defective Disc-Like Cu1.96S Anode Material with the Efficient Cu Vacancies for High-Performance Sodium-Ion Storage.

Due to their significant capacity and reliable reversibility, transition metal sulphides (TMSs) have received attention as potential anode materials for sodium-ion batteries (SIBs). Nonetheless, a prevalent challenge with TMSs lies in their significant volume expansion and sluggish kinetics, impeding their capacity for rapid and enduring Na+ storage. Herein, a Cu1.96S@NC nanodisc material enriched with copper vacancies is synthesised via a hydrothermal and annealing procedure. Density functional theory (DFT) calculations reveal that the incorporation of copper vacancies significantly boosts electrical conductivity by reducing the energy barrier for ion diffusion, thereby promoting efficient electron/ion transport. Moreover, the presence of copper vacancies creates ample active sites for the integration of sodium ions, streamlines charge transfer, boosts electronic conductivity, and, ultimately, significantly enhances the overall performance of SIBs. This novel anode material, Cu1.96S@NC, demonstrates a reversible capacity of 339mAhg-1 after 2000 cycles at a rate of 5Ag-1. In addition, it maintains a noteworthy reversible capacity of 314mAhg-1 with an exceptional capacity retention of 96% even after 2000 cycles at 20Ag-1. The results demonstrate that creating cationic vacancies is a highly effective strategy for engineering anode materials with high capacity and rapid reactivity.

Metal-electronegativity-induced sulfur-vacancies and heterostructures of MnS1-x/ZnS-NC@C with dual-carbon decoration for high-performance sodium-ion storage

Metal-electronegativity-induced sulfur-vacancies and heterostructures of MnS1-x/ZnS-NC@C with dual-carbon decoration for high-performance sodium-ion storage

Nano-bowl-like carbon confined 1T/2H-MoS2 hybrids as anode for high-performance sodium-ion storage

For sodium-ion batteries (SIB), MoS2 is considered as a promising anode material due to the suitable layer crystal structure and high theoretical capacity. However, the development of 2H-MoS2 is limited by the poor rate capability and bad cycling performance because of the low conductivity and the large change in volume. Here, a hybrid material (1T/2H-MoS2@HBC) is successfully synthesized, inwhich 1T/2H phases of MoS2 is researched as chief electrochemical active component, and hollow bowl-like carbon (HBC) is utilized as structural container to mitigate volume expansion and enhance electrical conductivity. The distinctive design of 1T/2H-MoS2@HBC contributes to the remarkable high reversible capacity (445 mAh g−1 at 1 A g−1) and the excellent rate performance (358 mAh g−1 at 5 A g−1). When the batteries are cycled for 2000 cycles, their discharge capacity remains at 349.3 mAh g−1. The coulomb efficiency close to 100 %, indicating excellent cyclic stability. Reaction kinetics are studied to verify the structure benefits of 1T/2H-MoS2@HBC. In addition, ex-situ and in-situ techniques are used to elucidate the reaction mechanism of 1T/2H-MoS2@HBC. Sodium-ion capacitor full cells are manufactured using the button cell architectures (1T/2H-MoS2@HBC||HBC), which offered long cycle life and comparatively low self-discharge rate. Based on the aforementioned results, 1T/2H-MoS2@HBC exhibits the potential for applications on sodium-ion energy conversion systems.

Controlled growth of a 2D/2D heterojunction for high-performance sodium ion storage

A Van der Waals epitaxial growth method is developed for constructing large-scale 2D/2D heterostructure based on graphdiyne and Ti2C3Tx. The heterojunction shows enhanced performance in storing the Na+.

Facile construction of flower-like MoO2/MoS2 heterostructures encapsulated in nitrogen-doped carbon for high-performance sodium-ion storage

The synergistic effects of multiple components and heterogeneous structures endow the MoO2/MoS2@NC anode with improved reaction kinetics for SIBs.

Structure and Defect Engineering of V3S4-xSex Quantum Dots Confined in a Nitrogen-Doped Carbon Framework for High-Performance Sodium-Ion Storage.

Constructing quantum dot-scale metal sulfides with defects and strongly coupled with carbon is significant for advanced sodium-ion batteries (SIBs). Herein, Se substituted V3S4 quantum dots with anionic defects confined in nitrogen-doped carbon matrix (V3S4-xSex/NC) are fabricated. Introducing element Se into V3S4 crystal expands the interlayer distance of V3S4, and triggers anionic defects, which can facilitate Na+ diffusions and act as active sites for Na+ storage. Meanwhile, the quantum dots tightly encapsulated by conductive carbon framework improve the stability and conductivity of the electrode. Theoretical calculations also unveil that the presence of Se enhances the conductivity and Na+ adsorption ability of V3S4-xSex. These properties contribute to the V3S4-xSex/NC with high specific capacity of 447 mAh g-1 at 0.2 A g-1, and prominent rate and cyclic performance with 504 mAh g-1 after 1000 cycles at 10 A g-1. The sodium-ion hybrid capacitors (SIHCs) with V3S4-xSex/NC anode and activated carbon cathode can achieve high energy/power density (maximum 144 Wh kg-1/5960 W kg-1), capacity retention ratio of 71% after 4000 cycles at 2 A g-1. This work not only synthesizes V3S4-xSex/NC, but also provides a promising opportunity for designing quantum dots and utilizing defects to improve the electrochemical properties.

Boost VS2 electrochemical reactive kinetics by regulating crystallographic planes and coupling carbon matrix for high performance sodium-ion storage

Boost VS2 electrochemical reactive kinetics by regulating crystallographic planes and coupling carbon matrix for high performance sodium-ion storage

Synergetic Coupling of Redox-Active Sites on Organic Electrode Material for Robust and High-Performance Sodium-Ion Storage.

Organic electrode materials (OEMs), valued for their sustainability and structural tunability, have been attracting increasing attention for wide application in sodium-ion batteries (SIBs) and other rechargeable batteries. However, most OEMs are plagued with insufficient specific capacity or poor cycling stability. Therefore, it's imperative to enhance their specific capacity and cycling stability through molecular design. Herein, we designed and synthesized a heteroaromatic molecule 2,3,8,9,14,15-hexanol hexaazatrinaphthalene (HATN-6OH) by the synergetic coupling of catechol (the precursor of ortho-quinone)/ortho-quinone functional groups and HATN conjugated core structures. The abundance of catechol/ortho-quinone and imine redox-active moieties delivers a high specific capacity of nine-electron transfer for SIBs. Most notably, the π-π interactions and intermolecular hydrogen bond forces among HATN-6OH molecules secure the stable long-term cycling performance of SIBs. Consequently, the as-prepared HATN-6OH electrode exhibited a high specific capacity (554 mAh g-1 at 0.1 A g-1 ), excellent rate capability (202 mAh g-1 at 10 A g-1 ), and stable long-term cycling performance (73 % after 3000 cycles at 10 A g-1 ) in SIBs. Additionally, the nine-electron transfer mechanism is confirmed by systematic density functional theory (DFT) calculation, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), and Raman analysis. The achievement of the synergetic coupling of the redox-active sites on OEMs could be an important key to the enhancement of SIBs and other metal-ion batteries.

Introducing Hybrid Defects of Silicon Doping and Oxygen Vacancies into MOF-Derived TiO2-X @Carbon Nanotablets Toward High-Performance Sodium-Ion Storage.

Titanium dioxide (TiO2 ) is a promising anode material for sodium-ion batteries (SIBs), which suffer from the intrinsic sluggish ion transferability and poor conductivity. To overcome these drawbacks, a facile strategy is developed to synergistically engineer the lattice defects (i.e., heteroatom doping and oxygen vacancy generation) and the fine microstructure (i.e., carbon hybridization and porous structure) of TiO2 -based anode, which efficiently enhances the sodium storage performance. Herein, it is successfully realized that the Si-doping into the MIL-125 metal-organic framework structure, which can be easily converted to SiO2 /TiO2-x @C nanotablets by annealing under inert atmosphere. After NaOH etching SiO2 /TiO2-x @C which contains unbonded SiO2 and chemically bonded SiOTi, thus the lattice Si-doped TiO2-x @C (Si-TiO2-x @C) nanotablets with rich Ti3+ /oxygen vacancies and abundant inner pores are developed. When examined as an anode for SIB, the Si-TiO2-x @C exhibits a high sodium storage capacity (285mAhg-1 at 0.2Ag-1 ), excellent long-term cycling, and high-rate performances (190mAhg-1 at 2Ag-1 after 2500 cycles with 95.1% capacity retention). Theoretical calculations indicate that the rich Ti3+ /oxygen vacancies and Si-doping synergistically contribute to a narrowed bandgap and lower sodiation barrier, which thus lead to fast electron/ion transfer coefficients and the predominant pseudocapacitive sodium storage behavior.

A heterogeneous structured C/SnO2/SnSe2@C hybrid: exploring the superior rate performance in sodium ion batteries

Transition metal oxides are regarded as the prospective anode materials for next-generation sodium-ion batteries owing to their high theoretical capacity. Nevertheless, its low conductivity and large volume variation obstruct its practical applications. In this study, a design of heterostructured SnO2/SnSe2 nanoparticles encapsulated by a carbon shell (C/SnO2/SnSe2@C) synthesized through a templating method and in-situ gas-phase selenization process. The rich heterostructures and the interfacial effect induced by a built-in electric field significantly accelerate reaction kinetics and enhance the reaction activity. When employed as an anode for sodium-ion batteries , C/SnO2/SnSe2@C electrodes achieve a superior rate performance (238.4 mAh/g at 5.0 A/g) and cycling performance (422.3 mAh/g at 0.1 A/g after 150 cycles; 289.7 mAh/g at 1.0 A/g after 200 cycles). A quantitative examination into the origin demonstrated that the Na+ storage is dominated by the fast surface redox reaction, which endows the heterostructure with a durable rate performance. Moreover, based on a dQ/dV analysis and in situ X-ray diffraction results, the C/SnO2/SnSe2@C anode has a hybrid mechanism of SnO2 (conversion and alloying reaction) and SnSe2 (intercalation, conversion, and alloying reactions). This strategy of the heterostructure design provides a potential route to develop high-performance sodium-ion storage materials and sheds light on the behavior of Na-storage mechanisms.

Hierarchical porous hard carbon derived from rice husks for high-performance sodium ion storage

Hierarchical porous hard carbon derived from rice husks for high-performance sodium ion storage

Heteroatom dopant strategy triggered high-potential plateau to non-graphitized carbon with highly disordered microstructure for high-performance sodium ion storage

Non-graphitized carbon (NGC) has been extensively utilized as carbonaceous anode in sodium-ion batteries (SIBs). However, more optimization to achieve competitive capacity and stability is still challenging for SIBs. In the study, the dopant strategy is utilized to construct nitrogen/sulfur-doped non-graphitized carbon (N-NGC or S-NGC) shell decorated on three-dimensional graphene foam (GF) as a self-support electrode. The highly disordered microstructures of heteroatom doped carbons are produced by applying a low-temperature pyrolysis treatment to precursors containing nitrogen and sulfur. The DFT calculations of Na-ion adsorption energies at diverse heteroatom sites show marginal-S, pyrrolic N and pyridinic N with more intensive Na-ion adsorption ability than middle-S, CO and pristine carbon. The N-NGC with dominant small graphitic regions delivers adsorption ability to Na-ion, while the S-NGC with significant single carbon lattice stripes demonstrates redox reaction with Na-ion. Evidently, in comparison with only adsorption-driven slope regions at high potential for N-NGC, the redox reaction-generated potential-plateau enables non-graphitized S-NGC superior discharge/charge capacity and cycle-stability in the slope region. This work could provide deep insight into the rational design of non-graphitized carbon with rich microstructure and composition.

Engineering the modulation of the active sites and pores of pristine metal–organic frameworks for high-performance sodium-ion storage

We adopted thermal treatment prior to carbonization for Ni-HHTP to open blocked pores and expose multiple active sites. The electronic conductivity, reaction kinetics, specific capacity and stability are enhanced using thermal treatment Ni-HHTP as an electrode for SIBs.

Multi-heterostructured SnO2/SnSx embedded in carbon framework for high-performance sodium-ion storage.

Heterostructure materials, as newborn electrode materials for rechargeable batteries, are attracting increasing attention due to their robust architectures and superior electrochemical performances. It is widely believed that the inner electric field induced at the interface can improve the electric conductivity and ion diffusion kinetics, thus enhancing the long-term stability and high-rate performance of the batteries. Although much progress is made on heterostructure construction, the performance of the batteries is still far from satisfying the commercial applications. In this work, a new type of SnO2/SnSx (x=1, 1.5) heterostructure embedded in carbon framework (C@SnO2/SnSx) is constructed via a facile sulfidation process. Compared to a single heterojunction, the multi-heterojunctions generated at SnO2/SnSx interface can induce an intensified built-in electric field, which promotes charge transportation and reaction kinetics of the electrode for Na-ions storage. Upon the sodiation process, the induced intensified electric field drives Na ions from Sn2S3 or SnO2 to SnS, while an inverse transportation of Na ions are accelerated upon the desodation process. As a result, C@SnO2/SnSx exhibits an outstanding reversible capacity of 510mAhg-1 after 300 cycles at 200mAg-1.

Dual anionic doping strategy towards synergistic optimization of Co9S8 for fast and durable sodium storage

Cobalt sulfides with high capacities and excellent redox activities have attracted comprehensive attention as promising anode materials for sodium-ion batteries (SIBs). However, the poor conductivity and large volume change during sodium storage render them an unprecedented challenge to rate capability and cycling stability. Herein, a dual anionic (N and Se) doping strategy is first proposed in the preparation of Co9S8 (N,Se-Co9S8) with structural and electronic optimization as anode material for SIB. It has been revealed that N doping can increase the electron density of Co9S8 at the Fermi level while Se doping could expand the lattice spacing and lower Co-S binding energy; the synergistic combination of N and Se enables Co9S8 to possess high conductivity, good Na+affinity, and effective Na+diffusion, leading to fast reaction kinetics and energetically stable performance upon charging/discharging. In consequence, the N,Se-Co9S8 delivers an exceptionally high capacity of 550 mAh g−1 at a current density of 0.1 A g−1, conspicuous rate performance of 411 mAh g−1 at 5 A g−1, and good cycling stability with a retained capacity of 406 mAh g−1 over 3000 cycles at 5 A g−1, among the best results of reported SIB anodes. The dual anionic doping strategy provides an efficient way to synergistically manipulate electrode materials for high-performance sodium ion storage.

Decoration of carbon encapsulated nitrogen-rich MoxN with few-layered MoSe2 nanosheets for high-performance sodium-ion storage

Transition metal nitrides have become the focus of research in sodium ion batteries (SIBs) due to their unique metal properties and high theoretical capacity. However, the low actual capacity is still the main bottleneck for their application. Herein, using Mo-aniline frameworks as precursors, the carbon encapsulated nitrogen-rich MoxN is decorated by few-layered MoSe2 nanosheets (MoSe2@MoxN/C-I) after the facile calcinating, selenizing, and nitriding. The carbon encapsulation can effectively strengthen the structural stability of MoxN. The nitrogen-rich MoxN and decoration of few-layered MoSe2 can create rich heterointerfaces and extra active sites for rapid sodium-ion storage, thus promoting reaction kinetics and improving actual capacity. The MoSe2@MoxN/C-I as an anode achieves a large reversible capacity of 522.8 mAh g−1 at 0.1 A g−1, and 254.3 mAh g−1 capacity is obtained after 6000 cycles at 5.0 A g−1, showing signally improved sodium-ion storage properties. The storage mechanisms and kinetic behaviors are described systematically via the advanced testing techniques and density functional theory (DFT) calculations. It is found that the nitrogen-rich MoxN as the substrate is the basis of long cycling stability, and the few-layered MoSe2 are the key to improving actual capacity. This work indicates that the decoration of few-layered selenides has a broad application prospect in high-performance metal-ion batteries.

New Cathode Materials in the Fe-PO4 -F Chemical Space for High-Performance Sodium-Ion Storage.

Sodium and iron make up the perfect combination for the growing demand for sustainable energy storage systems, given the natural abundance and sustainability of the two building block elements. However, most sodium–iron electrode chemistries are plagued by intrinsic low energy densities with continuous ongoing efforts to solve this. Herein, the chemical space of a series of (meta)stable, off‐stoichiometric Fe‐PO4‐F phases is analyzed. Some are found to display markedly improved electrochemical activity for sodium storage, as compared to the amorphous or thermodynamically stable phases of equivalent composition. The metastable crystalline Na1.2Fe1.2PO4F0.6 delivers a reversible capacity of more than 140 mAh g−1 with an average discharge potential of 2.9 V (vs Na+/Na0) resulting in a practical specific energy density of 400 Wh kg−1 (estimated at the material level), outperforming many developed Fe‐PO4 analogs thus far, with further multiple possibilities to be explored toward improved energy storage metrics. Overall, this study unlocks the possibilities of off‐stoichiometric Fe‐PO4‐F cathode materials and reveals the importance to explore the oft‐overlooked metastable or transient state materials for energy storage.

Boost Vs2 Electrochemical Reactive Kinetics by Regulating Crystallographic Planes and Coupling Carbon Matrix for High Performance Sodium Ion Storage

Boost Vs2 Electrochemical Reactive Kinetics by Regulating Crystallographic Planes and Coupling Carbon Matrix for High Performance Sodium Ion Storage