Anode Material For Sodium-ion Batteries Research Articles

2D Amorphous Iron Selenide Sulfide Nanosheets for Stable and Rapid Sodium-Ion Storage.

Sodium ion batteries (SIBs) suffer from large electrode volume change and sluggish redox kinetics for the relatively large ionic radius of sodium ions, raising a significant challenge to improve their long-term cyclability and rate capacity. Here, it is proposed to apply 2D amorphous iron selenide sulfide nanosheets (a-FeSeS NSs) as an anode material for SIBs and demonstrate that they exhibit remarkable rate capability of 528.7 mAh g-1 at 1 A g-1 and long-life cycle (10000 cycles) performance (300.4 mAh g-1 ). This performance is much more superior to that of the previously reported Fe-based anode materials, which is attributed to their amorphous structure that alleviates volume expansion of electrode, 2D nature that facilitates electrons/ions transfer, and the S/Se double anions that offer more reaction sites and stabilize the amorphous structure. Such a 2D amorphous strategy provides a fertile platform for structural engineering of other electrode materials, making a more secure energy prospect closer to a reality.

Cow leather-derived N/O codoped hard carbon as a high-performance anode material for sodium-ion batteries

Sodium-ion batteries (SIBs) have gained increasing attention owing to the abundant and cost-effective availability of sodium precursors. However, the quest for cost-effective and high-performing anode materials for SIBs remains a challenging task. In this study, we employed a straightforward pyrolysis method to fabricate nitrogen (N)- and oxygen (O)-doped hard carbon (HC) using waste cow leather, a low-cost biomass with high yield, as a carbon source. Our findings reveal that the pyrolysis temperature significantly influences the sodium storage performance of cow leather-derived HCs by modulating their microstructures and compositions. Specifically, the cow leather-derived HC pyrolyzed at 1100 °C exhibits a high reversible specific capacity of 207.9 mAh g−1 after 100 charge/discharge cycles at a current density of 0.1 C. Additionally, a reversible capacity of 142 mAh g−1 is maintained after 200 cycles at 1 C. Density functional theory (DFT) calculations validate that N/O codoping in HCs enhances the presence of defects and active sites and facilitates electron transfer, thereby improving sodium storage performance. This work provides insights into the sodium storage behavior of cow leather-derived HCs carbonized at different temperatures and presents a promising avenue for converting solid waste into high-performance anode materials for SIBs.

Hollow spheres of Co-doped V2O3 enveloped in N-doped carbon as efficient anode for sodium-ion storage

Vanadium oxides are potential anode materials for sodium-ion batteries, however, their application is limited for their rate capability and cycle life. Herein, hollow spheres of Co-doped V2O3 enveloped in N-doped carbon (Co-V2O3@NC) are prepared through a hydrothermal step with the following sintering process. The hollow spherical structure supplies short distance and large area for fast ion transfer kinetics, which also provides voids to ease the volume expansion. The strong coupling between Co-V2O3 nanoparticles and carbon layer constitutes a solid structure that enhances the conductivity and keeps electrode integrity. Co-doping introduces plenty of active sites for surface capacitance behavior and accelerates charge transfer. On account of the benefits, Co-V2O3@NC exhibits excellent Na+ storage properties as anode, including high capacity of 338.5 mAh g−1 at 0.1 A g−1, stable cycling capability of 240 mAh g−1 after 1000 cycles at 1 A g−1, and excellent rate performance. This work describes the importance of constructing specific structured materials for advanced anodes.

Enhanced Nitrogen-Doped Reduced Graphene Oxide-Embedded MnMoO4 as High-Capacity and Stable Anode for Sodium-Ion Batteries

Nanostructures of ternary metal oxides have been modified with nitrogen-doped reduced graphene oxide (rGO) to enhance electronic conductivity and also effectively mitigate volume variations in anodes used for sodium-ion batteries (SIBs). Unlike bimetallic metal oxides, ternary metal oxides undergo multiple redox reactions, resulting in high capacity. However, the effective anode type, MnMoO4 (MTMOs), is significantly challenged by volume expansion and contraction issues throughout the charge and discharge process, which leads to capacity decay and poor cyclability in SIBs. In this study, we report an N-doped rGO-embedded MnMoO4 composite as an excellent anode, that can withstand the volume accommodation related issue due to numerous active sites in MnMoO4. The as-prepared MnMoO4@rGO@g-C3N4 composite electrode exhibited a capacity of 135 mAh g−1 after 800 cycles at a high current density of 1 A g−1 and, the cell retained 58.2% of its initial capacity even after 900 cycles. The N-doped rGO-embedded MnMoO4 demonstrates superior electrochemical properties and holds promise as the next-generation anode material for sodium-ion batteries.

Ultrafine Ni0.85Se nanoparticles encapsulated inside hollow porous carbon spheres and their excellent Na storage performance

As a novel anode material for sodium-ion batteries, ultrafine Ni0.85Se nanoparticles encapsulated inside hollow porous carbon spheres (HPCS@Ni0.85Se) are prepared by impregnating Ni(NO3)2 into HPCSs, calcination and selenization, which is based on the strong capillary effect of HPCSs. Material characterization reveals that Ni0.85Se nanoparticles with a diameter of 5–15 nm are evenly dispersed and intimately coupled to the internal wall of HPCSs, and the content of Ni0.85Se reaches 52.81%. HPCSs as unique reactors and Ni0.85Se carriers improve electronic conductivity of Ni0.85Se, facilitate electrolyte penetration and storage, buffer volume variation of Ni0.85Se, effectively confine Ni0.85Se during long-term cycles. Consequently, HPCS@Ni0.85Se exhibits excellent cycling durability and extraordinary rate capability. High reversible capacities of 341 mA h g−1 at 1 A g−1 after 1000 cycles, 280 mA h g−1 at 5 A g−1 after 2000 cycles and 305 mA h g−1 at 10 A g−1 after 540 cycles are achieved. The reaction kinetics and Na + storage mechanism are further analyzed by galvanostatic intermittent titration technique, cyclic voltammetry and electrochemical impedance spectra measurements. Ex-situ characterizations confirm outstanding structural stability of HPCS@Ni0.85Se. It is demonstrated that HPCS@Ni0.85Se is an excellent anode material, and this unique HPCS-based nanoencapsulation structure is an effective composite strategy for transition metal selenides.

Molten salt splitting of CO2 with CaC2 and in-situ nitrogen doping for carbon anode of lithium/sodium-ion batteries

Carbon materials are the most attractive anodes for high-energy–density lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs). Herein, a molten salt method is developed to split CO2 with CaC2 for N-doped carbon anodes of LIBs and SIBs. Molten salt accelerates the carbonization and the in-situ N doping in kinetics. The carbon materials are characterized as large specific surface, porous and low graphite degree. The graphitization and functional groups are promoted by the doping of N atoms. These structure characteristics improve the battery performance, including high specific capacity, good rate performance and excellent cycle stability. The CN60–4 h anode delivers a reversible capacity of 448 mAh·g−1 over 500 cycles at 0.5 A·g−1 and 155 mAh·g−1 over 2000 cycles at 10 A·g−1 for the anode of LIBs and SIBs, respectively. This work offers an easy and feasible method for preparing N-doped carbon anode materials for LIBs and SIBs.

Insights into the electrochemical properties of bagasse-derived hard carbon anode materials for sodium-ion battery

Insights into the electrochemical properties of bagasse-derived hard carbon anode materials for sodium-ion battery

Recycling of waste coal-based filter materials into carbon anode materials for potassium and sodium-ion batteries

Recycling waste resources into electrode materials for energy storage is crucial for achieving sustainable societal advancements. In industrial production, anthracite can be employed as a filter material following the annealing process, which effectively reduces the ash content and facilitates the growth of nanographite-like domains within the material. In this work, waste coal-based filter materials are recycled into carbon anode materials for potassium and sodium-ion batteries through a simple pickling process. Mixed acid treatment is used to remove the impurities in the waste filter material without damaging the nanographite-like domain. The nanographite-like domains offer active sites for K+ insertion, while the stacked structure of these domains generates a large number of closed pores for Na+ pore filling. Additionally, the numerous grain boundaries facilitate rapid ion diffusion. When the waste filter material derived carbon is used as anode material for PIBs, it can display a reversible potassium storage capacity of 258.8 mAh/g at 0.05 A/g. For SIBs, it exhibits the reversible capacity of 247.2 mAh/g with an obvious platform at low voltage at 0.02 A/g. A sodium-ion full battery is assembled with WFC-1800 and Na3V2(PO4)3 as electrodes, exhibiting an energy density of 179.08 Wh/kg. These findings provide a new approach to tackle the challenge of coal-based waste utilization and promote progress in the field of large-scale storage applications.

Bismuth Nano-Rods Wrapped with Graphene and N-Doped C as Anode Materials for Potassium- and Sodium-Ion Batteries

Alloying-type anode materials have considerably promoted the development of potassium-ion batteries (PIBs) and sodium-ion batteries (SIBs), enabling them to achieve high-energy-density. However, large volume expansion and sluggish dynamic behavior have become key issues affecting electrochemical performance. Herein, bismuth (Bi) nano-rods are anchored on reduced graphene (rGO) and encapsulated via N-doped C (NC) to construct Bi@rGO@NC architecture as anode materials for SIBs and PIBs. The hierarchical confinement effect of three-dimensional conductive networks can not only improve electrode stability upon cycling via suppressing the large volume variation, but also eliminate the band gap of Bi and accelerate ion diffusion, thereby exhibiting favorable electrochemical reaction kinetics. Thus, Bi@rGO@NC contributes an ultra-long lifetime, over 1000 cycles, and an outstanding rate property to SIBs and PIBs. This work can pave the way for the construction of high-performance alloying-type anode materials for SIBs and PIBs.

ZnS/CoS@C Derived from ZIF-8/67 Rhombohedral Dodecahedron Dispersed on Graphene as High-Performance Anode for Sodium-Ion Batteries.

Metal sulfides are highly promising anode materials for sodium-ion batteries due to their high theoretical capacity and ease of designing morphology and structure. In this study, a metal-organic framework (ZIF-8/67 dodecahedron) was used as a precursor due to its large specific surface area, adjustable pore structure, morphology, composition, and multiple active sites in electrochemical reactions. The ZIF-8/67/GO was synthesized using a water bath method by introducing graphene; the dispersibility of ZIF-8/67 was improved, the conductivity increased, and the volume expansion phenomenon that occurs during the electrochemical deintercalation of sodium was prevented. Furthermore, vulcanization was carried out to obtain ZnS/CoS@C/rGO composite materials, which were tested for their electrochemical properties. The results showed that the ZnS/CoS@C/rGO composite was successfully synthesized, with dodecahedrons dispersed in large graphene layers. It maintained a capacity of 414.8 mAh g-1 after cycling at a current density of 200 mA g-1 for 70 times, exhibiting stable rate performance with a reversible capacity of 308.0 mAh g-1 at a high current of 2 A g-1. The excellent rate performance of the composite is attributed to its partial pseudocapacitive contribution. The calculation of the diffusion coefficient of Na+ indicates that the rapid sodium ion migration rate of this composite material is also one of the reasons for its excellent performance. This study highlights the broad application prospects of metal-organic framework-derived metal sulfides as anode materials for sodium-ion batteries.

Waste biomass garlic stem-derived porous carbon materials as high-capacity and long-cycling anode for lithium/sodium-ion batteries

Carbon materials are promising anode materials for rechargeable lithium and sodium-ion batteries, due to their low cost, high capacity, and structural designability. In this work, we selected a waste biomass, garlic stem, as the carbon precursor, and we systematically investigated the effect of pyrolysis temperature and time on their battery performance. We find that 800 °C and 2 h are the best pyrolysis conditions, which leads to the optimal carbon material (800C-2H) with a large layer spacing, abundant defect sites, high surface area, and sufficient micro/meso-porous structures. Due to these favorable properties, this carbon anode exhibits an impressive performance for Lithium-ion batteries, with a very high capacity of 480 mAh g−1 and no significant capacity fading after 3000 cycles. Besides, this anode also shows promising performance for Sodium-ion batteries, where a good capacity of 151.9 mAh g−1 and reasonable cycling of 100 cycles are achievable. We also carried out in-situ X-ray diffraction and in-situ Raman spectroscopy experiments to understand the relationship between carbon microstructures and their Li-ion storage.

Construction of Three-Dimensional Hierarchical CoSe2 Microflowers Assembled by Thin Nanosheets for High-Performance Sodium-Ion Batteries

Transition metal selenides are considered as promising anode materials for sodium-ion batteries (SIBs) due to their high capacity and low cost. However, they suffer from large volume change, serious polyselenide dissolution and sluggish reaction kinetics during charge/discharge process, resulting in poor cycling stability and low rate performance for SIBs, which further restrict their widespread application. Here, we developed carbon-free three-dimensional (3D) hierarchical microflower-shaped CoSe2 with a diameter size of approximately 2[Formula: see text][Formula: see text]m, composed of nanosheets through a one-step solvothermal method. The thin nanosheets are conducive to shortening the Na[Formula: see text] diffusion channels and relieving the volume expansion, and the 3D hierarchical microflower architecture could effectively prevent the agglomeration of nanosheets; accordingly, the resulting CoSe2 microflowers deliver a high specific capacity of 451.94[Formula: see text]mA[Formula: see text]h[Formula: see text]g[Formula: see text] even at 0.5[Formula: see text]A[Formula: see text]g[Formula: see text] after 100 cycles, compared with CoSe2 nanoparticles. This work offers an approach for designing metal selenides with high capacities and rate capability for SIBs.

Heteroatom screening and microcrystal regulation of coal-derived hard carbon promises high-performance sodium-ion batteries

Coal is a cost-effective and high-yield precursor for the carbon anode of sodium-ion batteries (SIBs). To enhance Na+ storage behavior, it is crucial to prevent long-range graphitization of microcrystals within the coal structure during high-temperature carbonization. Herein, we present a strategy to inhibit graphitized microcrystals of anthracite-derived carbon, which reveals the correlations between the initial Coulombic efficiency (CE) and heteroatom/defects. By introducing NH3 during the carbonization process of anthracite, it is possible to effectively remove the heteroatoms (O, S, etc.) in anthracite, while also expanding the spacing of carbon layers derived from anthracite. This results in obtaining high capacity and high initial CE. Using Nitrogen-doped anthracite hard carbon (N-AC-1200) as an anode material for SIBs, a high reversible capacity of 220 mA h g−1 at 0.1 A g−1 is achieved. Furthermore, a full cell assembled by Na2/3Ni1/3Mn2/3O2 (NNMO) cathode and N-AC-1200 anode delivers a high capacity of 76 mA h g−1 at 5C. The insights provided by this work will help guide the design of heteroatom-controlled hard carbon microcrystalline environment and provide new ideas for practical hard carbon electrode design principles.

Honeycomb-Structured MoSe2 /rGO Composites as High-Performance Anode Materials for Sodium-Ion Batteries.

Sodium-ion batteries are a promising substitute for lithium batteries due to the abundant resources and low cost of sodium. Herein, honeycomb-shaped MoSe2 /reduced graphene oxide (rGO) composite materials are synthesized from graphene oxide (GO) and MoSe2 through a one-step solvothermal process. Experiments show that the 3D honeycomb structure provides excellent electrolyte penetration while alleviating the volume change during electrochemical cycling. An anode prepared with MoSe2 /rGO composites exhibits significantly improved sodium-ion storage properties, where a large reversible capacity of 215mAhg-1 is obtained after 2700 cycles at the current density of 30.0Ag-1 or after 5900 cycles at 8.0Ag-1 . When such an anode is paired with Na3 V2 (PO4 )3 to form a full cell, a reversible specific capacity of 107.5mAhg-1 can be retained after 1000 cycles at the current of 1.0Ag-1 . Transmission electron microscopy, X-ray photoelectron spectroscopy and in situ X-ray diffraction (XRD) characterization reveal the reversible storage reaction of Na ions in the MoSe2 /rGO composites. The significantly enhanced sodium storage capacity is attributed to the unique honeycomb microstructure and the use of ether-based electrolytes. This study illustrates that combining rGO with ether-based electrolytes has tremendous potential in constructing high-performance sodium-ion batteries.

Sb/SnO@C composite prepared by electrospinning for high performance sodium ion battery anodes

The development of high-performance anode material for sodium-ion batteries remains a challenge because of their low capacity, which limits their commercial application. Compared with carbon-based materials, metallic Sb and SnO-based anodes have received extensive attention because of their high theoretical specific capacity and safe working potential. The main problem faced is the serious volume expansion during charging and discharging, leading to irreversible loss of capacity and poor cycle life. In this paper, Sb/SnO@C composite material with adjustable ratio of Sb/SnO was prepared via electrospinning by encapsulating Sb and SnO particles in lantern-like carbon nanocages which connected through the nanofibers. The unique structure can not only effectively mitigate the volume changes during the cycle, but also provide multiple effective paths for ion and electron transport. The kinetic analysis is further performed with the assist of CV and EIS. The results show that the prepared composite can provide impressive Na+ ions storage and transport performance, and can still deliver a reversible charging capacity of 413mAhg−1 after 200 cycles at a current density of 50mAg−1, with a capacity retention ratio of 84%. This work provides a new strategy for the development of sodium ion batteries with high capacity and stable cycle performance.

From charge storage mechanism to performance: A strategy toward boosted lithium/sodium storage through heterostructure optimization

Solving the problems of low electrical conductivity and poor cycling durability in transition metal oxides-based anode materials for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) has already turned into an urgent requirement. In this paper, we successfully synthesized Co2VO4/Co compounds with Co-V-MOF (metal-organic framework) as a sacrificial template and investigated their electrochemical mechanism in order to improve the electrochemical properties of LIBs and SIBs. The optimized heaping configuration and the existence of metallic Co catalyzed the formation of radical ions, thereby facilitating higher conductivity, shortening Li+ and Na+ transport paths, and providing more active sites. Co2VO4/Co constructed with 2-methylimidazole as a ligand showed a discharge capacity of 1605.1 mA h g−1 after 300 cycles at 0.1 A g−1 in LIB and 677.2 mA h g−1 in SIB. Density functional theory (DFT) calculation emphasizes the crucial role of Co2VO4/Co in enhancing electrode conductivity, decreasing the migratory energy barrier, and thereby strengthening electrochemical properties. This heterostructure building technique may pave the way for the development of high-performance LIBs and SIBs. Furthermore, the problem of the low first-loop coulombic efficiency faced by transition metal oxides is improved.

Atomistic insights into the enhanced Na storage performance of CuP2 anchored on single vacancy graphene

CuP2 is considered as a promising anode material for sodium-ion batteries due to its considerable theoretical capacity (1280 mAh/g), but it suffers from rapid decline of capacity and its cyclic reversibility should be further improved. As far as possible, preventing reaction energy barrier from sudden change and holding back Cu diffusion at atomic level both are key strategies to solve these problems occurring on the electrochemical reaction between CuP2 and Na. Based on the surface anchoring effect and excellent electronic conductivity of single vacancy graphene (SVG), first principles calculations have been carried out to capture the key role of SVG in regulating the electrochemical properties of CuP2. Firstly, among various (CuP2)n (n = 1–6) clusters, haploid CuP2 cluster possesses the fairly stable structure due to its highest HOMO-LUMO gap (2.45 eV) and lowest vertical electronic affinity energy (0.64 eV). Most of all, CuP2/SVG composites exhibit much more stable reaction energy barrier than CuP2 during their Na storage. It is attributed to the strong C–P and Cu–C anchoring effect between CuP2 and SVG, slowing the break of Cu–P bond. This contributes to holding back volume mutations of CuP2/SVG during Na storage. Besides, after conversion reaction between CuP2/SVG and Na, Cu showsdiffusion energy barrier of 0.75 eV, exhibiting great difficulty for its migration in reaction products. Compared with CuP2, CuP2/SVG not only exhibits more stable voltage distribution, but also it has much higher theoretical capacity (1851 mAh/g vs.1280 mAh/g). That is to say. CuP2/SVG can be acted as anode materials for Na-ion batteries with high energy density. And our results also provide a new way to design long-life CuP2-based anode materials for Na-ion batteries.

Synthesis of Iron Sulfide Nanocrystals Encapsulated in Highly Porous Carbon-Coated CNT Microsphere as Anode Materials for Sodium-Ion Batteries.

Highly porous carbon materials with a rationally designed pore structure can be utilized as reservoirs for metal or nonmetal components. The use of small-sized metal or metal compound nanoparticles, completely encapsulated by carbon materials, has attracted significant attention as an effective approach to enhancing sodium ion storage properties. These materials have the ability to mitigate structural collapse caused by volume expansion during the charging process, enable short ion transport length, and prevent polysulfide elution. In this study, a concept of highly porous carbon-coated carbon nanotube (CNT) porous microspheres, which serve as excellent reservoir materials is suggested and a porous microsphere is developed by encapsulating iron sulfide nanocrystals within the highly porous carbon-coated CNTs using a sulfidation process. Furthermore, various sulfidation processes to determine the optimal method for achieving complete encapsulation are investigated by comparing the morphologies of diverse iron sulfide-carbon composites. The fully encapsulated structure, combined with the porous carbon, provides ample space to accommodate the significant volume changes during cycling. As a result, the porous iron sulfide-carbon-CNT composite microspheres exhibited outstanding cycling stability (293mA h g-1 over 600 cycles at 1 A g-1 ) and remarkable rate capability (100mA h g-1 at 5 A g-1 ).

Sodium titanate nanorods decorated with silver nanoparticles as a high-performance anode material for sodium-ion batteries

Sodium titanate (Na2Ti6O13) exhibits great potential as a sodium-ion batteries (SIBs) anode material, nevertheless the limited electronic conductivity markedly hampers its applications. To combat this shortcoming, carbon coating has been widely employed to fabricate Na2Ti6O13/C composites; however, this method requires a high-temperature processing that is energy-intensive releases environmental pollutants. Herein, silver is used as a novel conducting agent, and we demonstrated a simple and efficient method to prepare Ag@Na2Ti6O13 composites. We find that nano-sized silver particles (3%) are well distributed on the Na2Ti6O13 surface, leading to boosted conductivity of the composites. As a result, the Ag@Na2Ti6O13 electrode exhibits an excellent performance for Na+ insertion, where after 100 cycles a discharge capacity of 189 mAh g−1 is achieved, demonstrating superior capacity retention of 97.9%. The result of silver coating on the battery performance was investigated coherently by various techniques, such as electrochemical impedance spectroscopy. Our work provides a feasible approach to prepare electronically conductive compounds for battery applications.

Carbon encapsulated FeS nanosheet-nanoribbon interwoven sandwich structure as efficient sodium-ion battery anodes

Carbon encapsulation and optimization of nanoparticle structure are key strategies in the development of battery electrode materials. Herein, we report a simple, one step chemical vapor deposition-like method to synthesize carbon encapsulated sandwich structured nanosheets/nanoribbons of ferrous sulphide (FeS@C NSRs) as a high performance sodium-ion battery anode material. The structurally advantageous FeS@C NSRs arises from heating Fe foam in the presence of a sulphur-containing resin, which supplies both the sulphur and carbon for the reaction. FeS@C NSRs maintains a high capacity of 582.8 mAh g−1 at 0.1 A g−1 for 120 cycles and a high rate capability of 270 mAh g−1 at 10 A g−1 for 2500 cycles. The impressive cycling performance results from fast electron and ion transfer with low structural strain on the bulk material. Furthermore, in situ Raman spectroscopy and XRD also reveal evidence that FeS@C NSRs cycles via a fully reversible conversion reaction pathway facilitated by the C–S–Fe bond. The efficient synthesis method could also be explored to produce other carbon coated transition metal sulphides for electrochemical applications.