Anode Material For Sodium-ion Batteries Research Articles

Anion Doping and Dual-Carbon Confinement Strategies to Synergistically Boost the Sodium Storage Performance of Cobalt-Based Sulfides.

Cobalt-based sulfides (CSs) are generally regarded as potentially valuable anode materials for sodium-ion batteries (SIBs) due to their excellent theoretical capacity and natural abundance. Nevertheless, their slow reaction kinetics and poor structural stability restrict the practical application of the materials. In this study, the dual-carbon-confined Se-CoS2@NC@C hollow nanocubes with anion doping are synthesized using ZIF-67 as the substrate by resorcin-formaldehyde (RF) encapsulation and subsequent carbonization and sulfurization/selenization. RF- and ZIF-67-derived dual-carbon skeleton hollow structures with a robust carbon skeleton and abundant internal space minimize cyclic stress, mitigate volume changes and maintain the structural integrity of the material. More importantly, Se doping increases the lattice spacing of CoS2, weakens the strength of Co-S bonds, and modulates the electronic structure around Co atoms, thereby optimizing the adsorption energy of the material. As a result, the hollow nanocubes of Se-CoS2@NC@C demonstrates excellent electrochemical performance as the anode for SIBs, delivering a high reversible capacity of 549.4 mAh g-1 at 0.5 A g-1 after 100 cycles and a superb rate performance (541.1 mAh g-1 at 0.2 A g-1, and 393.3 mAh g-1 at 5 A g-1). This study proposes a neoteric strategy for synthesizing advanced anodes for SIBs through the synergy of anion doping engineering and dual-carbon confinement strategy.

Revealing an Extended Adsorption/Insertion-Filling Sodium Storage Mechanism in Petroleum Coke-Derived Amorphous Carbon.

Amorphous carbon holds great promise as anode material for sodium-ion batteries due to its cost-effectiveness and good performance. However, its sodium storage mechanism, particularly the insertion process and origin of plateau capacity, remains controversial. Here, an extended adsorption/insertion-filling sodium storage mechanism is proposed using petroleum coke-derived amorphous carbon as a multi-microcrystalline model. Combining in situ X-ray diffraction, in situ Raman, theoretical calculations, and neutron scattering, the effective storage form and location of sodium ions in amorphous carbon are revealed. The sodium adsorption at defect sites leads to a high-potential sloping capacity. The sodium insertion process occurs in both the pseudo-graphite phase (d002 > 0.370nm) and graphite-like phase (0.345 ≤ d002 < 0.370nm) rather than the graphite phase, contributing to low-potential sloping capacity. The sodium filling into accessible closed pores forms quasi-metallic sodium clusters, contributing to plateau capacity. The threshold of the effective interlayer spacing for sodium insertion is extended to 0.345nm, breaking the consensus of insertion interlayer threshold and enhancing understanding of closed pore filling. The extended adsorption/insertion-filling mechanism explains the sodium storage behavior of amorphous carbon with different microstructures, providing theoretical guidance for the rational design of high-performance amorphous carbon anodes.

Research Status and Development Direction of Anode Materials for Sodium-ion Batteries

With the depletion of lithium resources, people gradually began to look for alternatives to lithium-ion batteries, and then sodium-ion batteries entered the public eye. In the past decade, sodium-ion batteries have developed at a high speed, establishing the beginning of the post-lithium era in the field of energy storage. This technology focuses on improving the performance of cathode and anode as well as electrolyte and optimising the preparation method of sodium-ion batteries. This paper mainly introduces the research status and development direction of anode materials for sodium-ion batteries. Firstly, the main structure of sodium-ion batteries is briefly introduced, and then it focuses on the electrochemical properties of several key anode materials such as carbon-based, titanium-based, organic-type and alloy-type anode materials, as well as the problems they face, and finally it takes the actual production and industrial application as a starting point to look ahead to the direction of the development of anode materials for sodium-ion batteries.

Interface stabilization strategy realizing low-temperature sodium storage in Sb anode prepared by ball milling method

Antimony (Sb) is an attractive anode material for sodium-ion batteries (SIBs) owing to its low operating potential, low cost, and high theoretical capacity. However, the large volume expansion of Sb during the Na alloying/dealloying process, which greatly limits its application in SIBs. Simultaneously, as the temperature decreases, the formation of a poor coating on the anode surface significantly increase the difficulty of Na+ transmission. Herein, Sb-graphite-NaF (SCF) ternary composites were prepared by an easy to operate and low-cost ball milling method, which significantly improved the cycling stability and extended to the operation temperature of Sb-base SIBs. A small amount of NaF induces the formation of an inorganic-dominated NaF-rich stable solid electrolyte interphase (SEI) on the Sb anode surface, which can cooperate with graphite to inhibit volume expansion of the Sb particles during sodium storage, enhance conductivity and accelerate Na+ diffusion at room and low temperatures. As a result, the SCF electrode with propylene carbonate-base electrolyte delivered a discharge capacity of 458.4 mAh g−1 after 160 cycles at 500 mA g−1 at 20 °C. When matched with diethylcarbonate-based electrolyte at −20 °C, it had a specific capacity of 299.8 mAh g−1 after 120 cycles and a capacity retention rate of 86.2 %. This study shows that the interface stabilization strategy with a suitable electrolyte can improve the cycling stability of anode materials, provide a new idea for constructing NaF-rich SEI, and a new approach for applying Sb-based materials in low-temperature SIBs.

Chloride-Ion-Enriched Solid Electrolyte Interphase with Rapid Na+ Migration toward High-Performance Sodium-Ion Batteries.

Sodium-ion batteries (SIBs) have emerged as potential alternatives to lithium-ion batteries (LIBs), particularly for large-scale applications. Alloy-type anode materials for sodium-ion batteries are esteemed as prospective candidate materials for sodium-ion anodes, owing to their elevated theoretical capacity, heightened utilization efficiency, and minimal production of insulating byproducts. However, the severe volume changes and sluggish ion diffusion kinetics can lead to irreversible particle fragmentation and reaggregation phenomena, ultimately resulting in electrode degradation. Additionally, repetitive volume changes can cause an unstable solid electrolyte interphase (SEI). This study presents the synthesis of chloride-ion-modulated bimetallic SnSb/C nanoparticle anode materials, highlighting the following advantages: (i) Designing a bimetallic SnSb alloy structure serves to buffer the structural stresses generated during sodium insertion/extraction processes, effectively mitigating particle fracture phenomena induced by electrode material expansion/contraction. (ii) Nanostructuring both alloy materials enables the full utilization of active materials and shortens diffusion pathways, thereby significantly enhancing the diffusion rate of sodium ions. (iii) Introducing a carbonaceous matrix serves to alleviate self-agglomeration phenomena of the material during charge/discharge cycles, enhancing the material's conductivity and structural stability. (iv) Utilizing chloride-ion interface modification to achieve a chloride-rich solid-electrolyte interphase (SEI) enhances battery performance.

Insights into Na ion adsorption and diffusion in biphenylene as an anode material for sodium-ion batteries: A first-principles study

Anode materials are essential for the advancement of sodium-ion batteries (NIBs). This study comprehensively evaluates the biphenylene network (BP) as a promising anode material using first-principles calculations. Density functional theory (DFT) results reveal that sodium (Na) ions stably adsorb on BP surfaces, with adsorption energies ranging from −1.29 eV to −2.92 eV, due to effective charge transfer and hybridization between Na (s) and carbon (p) orbitals. The diffusion barriers for Na ion migration are 0.31 eV for the monolayer and 0.76 eV for the bilayer, with optimal paths involving the C8-ring and passing through C6- or C4-rings. Notably, edge sites were found to provide strong Na adsorption on monolayer BP nanoribbon, with low diffusion barriers (0.36 eV), revealing the critical role of edge configurations in enhancing the BP performance as an anode material. The theoretical capacity of Na on the BP monolayer is 908.52 mAh·g⁻¹, surpassing many other two-dimensional materials, and the average open circuit voltage (OCV) is 0.64 V. Overall, BP offers high Na storage capacity, low diffusion barriers, and suitable OCV, positioning it as a strong candidate for high-performance NIB anodes.

Large-Scale Synthesis of N,S Codoped Carbon-Modified Fe0.975S Composites as a Novel Anode for Lithium/Sodium Ion Batteries with Enhanced Performance.

To overcome obstacles hindering the commercialization of lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs), we introduce a cost-effective single-step sulfurization strategy for synthesizing iron sulfide (Fe0.975S) nanohybrids, augmented by N,S codoped carbon. The resulting N,S codoped carbon-coated Fe0.975S (Fe0.975S@NSC) electrode exhibits exceptional potential as a highly reversible anode material for both LIBs and SIBs. With impressive initial discharge and charge capacities (1658.2 and 1254.9 mAh g-1 for LIBs and 1450.9 and 1077.1 mAh g-1 for SIBs), the electrode maintains substantial capacity retention (900 mA h g-1 after 1000 cycles for LIBs and 492.5 mA h g-1 after 600 cycles for SIBs at 1.0 A g-1). The LiMn2O4//Fe0.975S@NSC and Na3V2(PO4)3//Fe0.975S@NSC full batteries can maintain excellent reversible capacity and robust cycling stability. Ex situ and in situ X-ray diffraction, density functional theory (DFT) calculations, and kinetics analysis confirm the promising energy storage potential of the Fe0.975S@NSC composite.

Precisely Tunable Instantaneous Carbon Rearrangement Enables Low-Working-Potential Hard Carbon Toward Sodium-Ion Batteries with Enhanced Energy Density.

As the preferred anode material for sodium-ion batteries, hard carbon (HC) confronts significant obstacles in providing a long and dominant low-voltage plateau to boost the output energy density of full batteries. The critical challenge lies in precisely enhancing the local graphitization degree to minimize Na+ ad-/chemisorption, while effectively controlling the growth of internal closed nanopores to maximize Na+ filling. Unfortunately, traditional high-temperature preparation methods struggle to achieve both objectives simultaneously. Herein, a transient sintering-involved kinetically-controlled synthesis strategy is proposed that enables the creation of metastable HCs with precisely tunable carbon phases and low discharge/charge voltage plateaus. By optimizing the temperature and width of thermal pulses, the high-throughput screened HCs are characterized by short-range ordered graphitic micro-domains that possess accurate crystallite width and height, as well as appropriately-sized closed nanopores. This advancement realizes HC anodes with significantly prolonged low-voltage plateaus below 0.1V, with the best sample exhibiting a high plateau capacity of up to 325mAhg-1. The energy density of the HC||Na3V2(PO4)3 full battery can therefore be increased by 20.7%. Machine learning study explicitly unveils the "carbon phase evolution-electrochemistry" relationship. This work promises disruptive changes to the synthesis, optimization, and commercialization of HC anodes for high-energy-density sodium-ion batteries.

Sugarcane bagasse derived carbon aerogels as anode materials for sodium-ion batteries

Biomass-derived carbons have been regarded as promising anode materials for sodium-ion batteries due to their tunable physicochemical properties, economic value, and environmental considerations. Nowadays, most of biomass-derived carbon materials are directly prepared through a one-step carbonization process, which may damage the inherent structure of biomass materials. In this work, hydrothermal and freeze-drying pretreatment before carbonization was employed to prepare sugarcane bagasse derived carbon aerogels, which can preserve the unique structure of the biomass material. When utilized as anode materials for sodium-ion batteries, the optimized carbon aerogel delivered an initial discharge capacity as high as 380 mAh g−1 at a current density of 50 mA g−1. After 50 cycles, the reversible specific capacity was still maintained at 248 mAh g−1.

Synergetic benefits of zinc antimony oxide/reduced graphene oxide hybrid anode for enhanced sodium-ion storage

Organic-inorganic hybrid nanocomposites are rapidly evolving as a new generation of materials with attractive properties for electrochemical energy storage. Unfortunately, their practical applications in sodium-ion batteries (SIBs) still require further research due to the unsatisfactory cycling stability and rate performance. This work explores using zinc antimony oxide/reduced graphene oxide (ZSO/rGO) hybrid nanocomposite as an anode material in SIBs. After 150 cycles at 0.05 A g-1, the ZSO/rGO electrode delivers a specific capacity of 357.21 mAh g-1 with a coulombic efficiency of 99.3%, which is almost 2.5-fold higher than the specific capacity of the pristine ZSO electrode. An in-situ Raman spectroscopy study demonstrates that the sodiation/desodiation mechanism in the ZSO/rGO electrode involves the conversion and alloying reactions in the ZSO nanoparticles. Further electrochemistry analysis reveals that the nanocomposite anode shows synergistic effects by coupling diffusion and surface contribution, in which the latter plays an important role.

3D printing of porous hollow nanosphere MoS2@NiS/rGO scaffolds empowering long-cycle sodium-ion batteries

Sodium-ion batteries (SIB), as one of the most appealing electrochemical energy storage devices in the field of energy storage, consistently require optimization for both capacity and long-term cycling performance. The amalgamation of diverse material modification techniques with up-and-coming 3D printing technology presents a promising yet relatively underexplored avenue. Herein, we report a composite material, MoS2@NiS/rGO, as the anode material for SIB, achieving high reversible capacity and outstanding long-term cycling performance, surpassing current reported levels. Through carefully designed anode electrode structure and component interface engineering, the material rate capability (with a capacity of 289.5 mAh g-1 at 0.1Ag-1 and 66.8 mAh g-1 at 5Ag-1) and cycling stability (maintaining a capacity of 131.3 mAh g-1 after 800 cycles at 1Ag-1) are significantly enhanced. The reasons for the improvement in electrochemical performance are elucidated through detailed electrochemical analysis. Encouragingly, we showcase the fabrication of a sodium-ion full battery entirely through 3D printing (3DP), achieving an area loading capacity as high as 8.23mgcm-2 and retaining a capacity of 82.1 mAh g-1 after 240 cycles at 0.1Ag-1. This work underscores the pivotal significance of 3D-printed sodium-ion batteries in advancing the frontier of energy storage technology.

Engineering (FeSn)/S nanocubes heterojunctions for improved sodium ion battery performance

Transition metal sulfides have emerged as compelling anode materials for sodium-ion batteries (SIBs), leveraging their abundant elemental reserves and high theoretical capacities. However, the reaction of sulfur with Na ions is usually accompanied by significant volume dilation, which hinders their further development and application. Hence, constructing bimetallic sulfide (FeSn)/S for SIBs anode material greatly alleviates the circulation attenuation caused by volume expansion. Through constructing bimetallic heterojunction materials from nanocube precursors, the (FeSn)/S anode material retains a high specific capacity of 578 mAh/g at an intense current density of 2 A/g after 1000 cycles, and exhibits an great rate capability, delivering 796 mAh/g at 100 mA/g. The excellent electrochemical performance of the heterojunction material presents a promising solution to the enduring quest for enhanced anode material for SIBs.

Manipulating Micropore Structure of Hard Carbon as High‐Performance Anode for Sodium-Ion Batteries

Hard carbon (HC) is the most promising anode material for sodium-ion batteries (SIBs), but its low initial coulombic efficiency (ICE) and specific capacity limit its practical application. Herein, a chemical vapor deposition (CVD) strategy is used to address these challenges via filling the micropores of sucrose-based HC with pyrolysis by-products from acetonitrile, thereby reducing the specific surface area of HC microspheres. This approach mitigates the formation of solid electrolyte interphase (SEI) film leading to an enhancement in ICE. Moreover, the conversion of open micropores into closed pores creates additional storage space for sodium ions, effectively extending the specific capacity within the plateau region. Specifically, the HC prepared with a deposition duration of 1 hour demonstrates the most favorable electrochemical performance. The optimal HC anode manifests an enhanced specific capacity of 307.6 mAh g−1 with an ICE of 66.01% and exhibits excellent cycle stability (84.9% capacity retention after 200 cycles at 100 mAh g−1). This study provides a feasible approach to optimize hard carbon anode materials for SIBs.

A low redox potential and long life organic anode material for sodium-ion batteries

Sodium-ion batteries (SIBs) with organic electrodes are an emerging research direction due to the sustainability of organic materials based on elements like C, H, O, and sodium ions. Currently, organic electrode materials for SIBs are mainly used as cathodes because of their relatively high redox potentials (>1 V). Organic electrodes with low redox potential that can be used as anode are rare. Herein, a novel organic anode material (tetrasodium 1,4,5,8-naphthalenetetracarboxylate, Na4TDC) has been developed with low redox potential (<0.7 V) and excellent cyclic stability. Its three-sodium storage mechanism was demonstrated with various in-situ/ex-situ spectroscopy and theoretical calculations, showing a high capacity of 208 mAh g−1 and an average decay rate of merely 0.022% per cycle. Moreover, the Na4TDC-hard carbon composite can further acquire improved capacity and cycling stability for 1200 cycles even with a high mass loading of up to 20 mg cm−2. By pairing with a thick Na3V2(PO4)3 cathode (20.6 mg cm−2), the as-fabricated full cell exhibited high operating voltage (2.8 V), excellent rate performance and cycling stability with a high capacity retention of 88.7% after 200 cycles, well highlighting the Na4TDC anode material for SIBs.

Electrochemical sodium storage properties in monolayer VOPO4: A density functional theory prediction

The unique structural properties of two-dimensional materials make them promising for energy storage applications. This work theoretically predicts for the first time that Monolayer VOPO4 (MNL VOPO4), exfoliated from the delithiated phase of tetragonal LiVOPO4, is stable at room temperature, exhibiting excellent thermodynamic and kinetic stability, thus making it a promising high-capacity anode material for sodium-ion batteries (SIBs). Compared to bulk VOPO4, the monolayer structure significantly reduces the sodium ion migration energy barrier from 1.006 to 0.0795 eV, thereby markedly enhancing sodium ion migration kinetics. MNL VOPO4 can adsorb up to 32 sodium ions, corresponding to a theoretical capacity of 634.88 mA h g−1 and an energy density of 895.18 Wh kg−1. Furthermore, the excellent structural stability of MNL VOPO4 favors its cycling performance during charge and discharge processes. This work provides theoretical insights for better utilizing and developing multi-atomic phosphate compounds as electrode materials for secondary batteries.

Sodium storage performance and mechanism of amorphous FePO4/rGO nanocomposite as a novel anode material for sodium ion batteries

Exploring novel and cost-effective anode materials is highly desired for the development of sodium-ion batteries (SIBs). Herein, an amorphous FePO4/reduced graphene oxide (FP-G) composite is prepared by a simple chemical precipitation method with leaching liquor of jarosite residue as Fe source. When used as a novel anode material for SIBs, this FP-G composite exhibits a high sodium storage activity (341.6 mAh g−1 after 100 cycles at 0.2 A g−1), superior long-term cycling stability (215.8 mAh g−1 after 1500 cycles at 0.5 A g−1), and outstanding high-rate capability (190.8 mAh g−1 at 5.0 A g−1). The FP-G composite shows a significant pseudocapacitance behavior and good electrochemical reversibility during discharge and charge processes. This work proposes a simple, feasible, and cost-effective strategy for the high-valued utilization of jarosite residue, and deeply investigates the sodium storage mechanism and potential value of FP-G composite as a novel anode material for SIBs.

Synergistic effect of in-situ carbon-coated mixed phase iron oxides and 3d electrode architectures as anodes for high-performance sodium-ion batteries

Due to the high theoretical capacity, iron-oxide-based Fe2O3 (1007 mAh g−1) and Fe3O4 (926 mAh g−1) materials can be a promising conversion-type anode material for Sodium-ion batteries (SIBs). However, the low electronic conductivity (10−14 S cm−1) and 200% volume expansion of iron oxide lead to poor cycle life and capacity retention, limiting its commercial application. In this work, carbon-coated mixed-phase iron oxide C-Fe2O3-Fe3O4 (C-IO) was synthesized by pyrolysis using ferrocene precursor. Subsequently, a 3D carbon fiber (CF) network was introduced to improve the electrochemical performance of the material by resolving the volume expansion and pulverization issues. Both the CF network and Fe3O4 provide an electron transport pathway. The conventional Cu-C-IO electrodes deliver a 2nd cycle capacity of 335 mAh g−1 at 250 mA g−1 and exhibit 61.5% capacity retention after 500 cycles. In contrast, the 3D-CF-based IO electrodes show 2nd cycle capacity of 607 mAh g−1 at 50 mA g−1 with 96.4% capacity retention after 35 cycles and 420 mAh g−1 with ∼85.4% capacity retention after 500 cycles at 250 mA g−1 (w.r.t. CF and C-IO active mass, CF contribute ∼ 27% and C-IO ∼ 73% capacity), making it a potential anode for SIBs.

3D MoS2/graphene oxide integrated composite as anode for high-performance sodium-ion batteries

Sodium-ion batteries (SIBs) are emerging as a promising alternative to conventional lithium-ion technology, due to the abundance of sodium resources. The major drawbacks for the commercial application of SIBs lie in the slow kinetic processes and poor energy density of the devices. Molybdenum sulfide (MoS2), a graphene-like material, is becoming a promising anode material for SIBs, because of its high theoretical capacity (670 mAh g–1) and layered structure that suitable for Na+ intercalation/extraction. However, the intrinsic properties of MoS2, such as low conductivity, slow Na+ diffusion kinetics and large volume change during charging/discharging, restrict its rate capability and cycle stability. Here, molybdenum disulfide and graphene oxide (3D MoS2/GO) with excellent conductivity were fabricated through layer-by-layer method using amino-functionalized SiO2 nanospheres as templates. The 3D MoS2/GO composite demonstrates excellent cycling stability and capacity of 525 mA h g–1 at 500 mA g–1 after 100 cycles, which mainly due to the integrated MoS2/GO components and unique 3D macroporous structure, facilitating the material conductivity and Na+ diffusion rate, while tolerating the volume expansion of MoS2 during the charge/discharge processes.

Investigating the Electrochemical Performance of MnFe2O4@xC Nanocomposites as Anode Materials for Sodium-Ion Batteries.

Transition metal oxides (TMOs) are important anode materials in sodium-ion batteries (SIBs) due to their high theoretical capacities, abundant resources, and cost-effectiveness. However, issues such as the low conductivity and large volume variation of TMO bulk materials during the cycling process result in poor electrochemical performance. Nanosizing and compositing with carbon materials are two effective strategies to overcome these issues. In this study, spherical MnFe2O4@xC nanocomposites composed of MnFe2O4 inner cores and tunable carbon shell thicknesses were successfully prepared and utilized as anode materials for SIBs. It was found that the property of the carbon shell plays a crucial role in tuning the electrochemical performance of MnFe2O4@xC nanocomposites and an appropriate carbon shell thickness (content) leads to the optimal battery performance. Thus, compared to MnFe2O4@1C and MnFe2O4@8C, MnFe2O4@4C nanocomposite exhibits optimal electrochemical performance by releasing a reversible specific capacity of around 308 mAh·g-1 at 0.1 A·g-1 with 93% capacity retention after 100 cycles, 250 mAh·g-1 at 1.0 A g-1 with 73% capacity retention after 300 cycles in a half cell, and around 111 mAh·g-1 at 1.0 C when coupled with a Na3V2(PO4)3 (NVP) cathode in a full SIB cell.

Se-vacancy porous ultrathin ZnSe nanosheet/carbon composite for sodium storage via electron beam irradiation strategy

Zinc selenide (ZnSe) is a next-generation anode material due to its high sodium storage capacity. However, the poor conductivity and volume expansion lead to its capacity attenuation and short cycle life. Herein, Se-vacancy porous ultrathin ZnSe nanosheet/carbon composite (ZnSe@NC/N-GQD) is reported as a high-performance anode material for sodium-ion batteries. Organic-inorganic hybrid ZnSe(en)0.5 ultrathin nanosheets with abundant Se vacancies are rapidly prepared by electron beam irradiation for the first time. Using it as a precursor, Se-vacancy carbon-coated porous ultrathin ZnSe nanosheets loaded with nitrogen-doped graphene quantum dots (N-GQDs) are synthesized via carbonization and electrodeposition process. Through the design of ZnSe@NC/N-GQD, the sodium storage performance can be effectively improved by implementing nanostructure engineering (porous ultrathin nanosheet) via organic–inorganic hybrid, defect engineering (Se vacancy) via electron beam irradiation, and carbon composite (amorphous carbon and N-GQD). Consequently, ZnSe@NC/N-GQD delivers a high capacity of 483 mA h g−1 after 200 cycles at 0.5 A g−1, shows an outstanding rate capability of 381 mA h g−1 at 10.0 A g−1, and exhibits an excellent cycling stability of 86 % retention after 2800 cycles at 5.0 A g−1. This work develops a new method to rapidly prepare organic–inorganic nanohybrids, and proposes an innovative design of high-performance ZnSe-based anodes.