Anode Material For Sodium-ion Batteries Research Articles

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.

Multiple heteroatom-doped cobalt sulfoselenide@C yolk-shell microsphere as excellent anode materials for sodium-ion batteries and their conversion reaction mechanism with sodium ions

To address the sluggish reaction kinetics commonly associated with the transition metal chalcogenide anodes in their interaction with alkali metal ions, introducing heterostructures into these materials is proposed as a novel approach. Herein, we introduce a fabrication method for yolk-shell structured microsphere comprising heteroatom-doped cobalt sulfoselenide nanocrystals using a recycled solution. The prepared material demonstrates a composition of sulfur-doped cobalt selenide, forming hetero-anion metal compounds. A detailed study of the reaction mechanism in cobalt sulfoselenide reveals the formation of Na2S/Na2Se heterointerfaces during the conversion reaction, which facilitate a rapid diffusion of Na-ions. Furthermore, heteroatom doping in the cobalt sulfoselenide nanocrystals, induced by cobalt recycling process, leads to the lattice expansion, further enhancing the Na-ion diffusion kinetics. Additionally, through an infiltration of pitch solution and a simple heat-treatment, pitch-derived carbon is coated on the cobalt sulfoselenide nanocrystals. This carbon layer can effectively accommodate the volumetric stress during repeated cycling, enhancing the stability. Consequently, carbon-coated heteroatom-doped cobalt sulfoselenide yolk-shell microsphere anode exhibits stable cycling stability (560 mA h g−1 for 100 cycles at 0.2 A g−1) as well as great rate capability (140 mA h g−1 at 15 A g−1) for sodium-ion batteries (SIBs).

O-Targeted Carbon Hybrid Orbital Conversion to Produce sp2-Rich Closed Pores for Sodium-Storage Hard Carbon.

Biomass-based hard carbon has the advantages of a balanced cost and electrochemical performance, making it the most promising anode material for sodium-ion batteries. However, due to the structural limitations of biomass (such as macropores and impurities), it still faces the problems of low specific capacity and initial Coulombic efficiency (ICE). Herein, an integrated strategy of biomass liquefaction and oxidation treatment is proposed to fabricate hard carbon with low ash content and sp2-rich closed pores. Specifically, liquefaction treatment can break through the inherent constraints of biomass, while oxidation treatment with O-targeted effect can directionally convert C─C/C─O bonds into C═O/O═C─O bonds, which would promote the formation of closed pores and the rearrangement into sp2-carbon within the graphene layer. Moreover, it is well demonstrated that the hard carbon interface rich in sp2 hybridization can induce the generation of an inorganic-rich solid electrolyte interface, contributing to fast ion migration and excellent interfacial stability. As a result, the optimized hard carbon with maximum closed pore volume and sp2/sp3 ratio can exhibit a high capacity of 347.3mAhg-1 at 20mAg-1 with the ICE of 90.5%, and a capacity of 110.4mAhg-1 at 5.0Ag-1 after 10000 cycles.

Progress on Copper-Based Anode Materials for Sodium-Ion Batteries.

Fossil fuels have clearly failed to meet people's growing energy needs due to their limited reserves, potential pollution of the environment, and high costs. The development of cleaner, renewable energy sources as well as secondary batteries for energy storage is imminent, in a modern society where energy demand is soaring. Sodium-ion batteries (SIBs) have become the focus of large-scale energy storage systems as a promising alternative to lithium-ion batteries. The development of SIBs relies on the construction of high performance electrode materials. The design of low cost and high performance anode materials is a key link in this regard. Copper-based anodes are characterized by high theoretical capacity, abundant reserves, low cost and environmental friendliness. A variety of copper-based anode materials, which include cobalt oxides, sulfides, selenides and phosphides, have been synthesized and evaluated in the scientific literature for sodium storage. In detail, the preparation methods, response mechanisms, strengths and weaknesses, the relationship between morphology structure and electrochemical performance are discussed, as well as highlighting strategies to improve the electrochemical performance of copper-based anode materials. Finally, we offer our perspective on the challenges and potential for the development of copper-based anodes as a means of developing practical and high performing SIBs.

Understanding the Sodium Storage Behavior of Closed Pores/Carbonyl Groups in Hard Carbon.

Hard carbon (HC) is a promising anode material for sodium-ion batteries. However, the intrinsic relationship between the closed pores/surface groups and sodium storage performance has been unclear, leading to difficulties in targeted regulation. In this study, renewable tannin extracts were used as raw materials to prepare HC anodes with abundant tunable closed pores and carbonyl groups through a pyrolytic modulation strategy. Combining ex situ characterizations reveals that closed pores and carbonyl groups are regulated by the pyrolytic process. Further, it is demonstrated that the plateau region is mainly contributed by the closed pores; highly stable fluorine-rich solid electrolyte interphase compositions are produced through carbonyl-induced interfacial catalysis. The optimized HC anode displays good cycling stability, exhibiting a high reversible capacity (360.96 mAh g-1) at 30 mA g-1 and capacity retention of up to 94% after 500 cycles at 1 A g-1. Moreover, the full battery assembled with Na3V2(PO4)3/C demonstrates a stable cycling performance. These findings provide a fresh knowledge of the structural design of high-performance HC anode materials and the mechanism of sodium storage in HC.

Design and Synthesis of Sb-doped CuS@C Hollow Nanocubes as Efficient Anode Materials for Sodium-Ion Battery.

CuShave received widespread attention for application as anode materials in sodium-ion batteries due to their potent capabilities and eco-friendly properties. However, it is a challenge to achieve a high rate capability and long cycle stability owing to the heterogeneous transfer of sodium ions during charge-discharge, the interior poor electron conductivity and repeated volumetric expansion of copper sulfide. In this study, Sb-doped CuS hollow nanocubes coated with carbon shells (Sb-CuS@C) was designed and constructed as anode nanomaterials in sodium ion batteries. Thanks to the intrinsic good electron conductivity and chemical stability of carbon shells, Sb-CuS@C possesses a higher overall electron transfer as anode material, avoids agglomeration and structural destruction during the cycling. As a result, the synthesized Sb-CuS@C achieved an excellent reversible capacity of 595 mA h g-1 after 100 cycles at 0.5 A g-1 and a good rate capability of 340 mA h g-1 at a higher 10 A g-1. DFT calculations clarify that the uniformly doped Sb would act as active sodiophilic nucleation sites to help adsorbing Na+ during discharging and leading uniform sodium deposition. This work provides a new insight into the structural and componential modification for common transition-metal sulfides towards application as anode materials in SIB.

Engineering multiple heterogeneous Co/CoSe/MoSe2 embedded in carbon nanofibers with Co/Mo–Se–C bonding towards high performance sodium ion capacitors

MoSe2, as a representative two-dimensional transition selenide with a broad interlayer distance of 0.65 nm and a high theoretical capacity of 422 mAh g−1, is considered an optimal anode material for sodium-ion batteries (SIBs). However, its unsatisfactory electrical conduction and structural instability often lead to severe capacity decay during cycling, hindering its large-scale application in SIBs. To overcome these challenges, coupling heterostructures has been identified as an effective solution. The establishment of multiple heterointerfaces can minimize interface diffusion resistance, significantly enhancing ion and electron delivery dynamics compared to a single component. In this work, multiple heterogeneous Co/CoSe/MoSe2 uniformly distributed in carbon nanofibers (CNF) via Co/Mo–Se–C bonding are successfully synthesized using electrospinning and subsequent calcination. Importantly, the Co/CoSe and Co/MoSe2 heterointerfaces can greatly accelerate charge transfer and improve Na + adsorption capability compared to the CoSe/MoSe2 heterostructure, as corroborated by theoretical calculations. Given the high rate performance of Co/CoSe/MoSe2@CNF as an anode in SIBs (267.9 mAh g−1 at 5 A g−1), a rocking-chair sodium-ion capacitor (SIC) incorporating a Co/CoSe/MoSe2@CNF anode and a Na3V2(PO4)3 cathode is proposed, delivering high energy densities of 199.1 Wh kg−1 at 180 W kg−1 and 126.8 Wh kg−1 at 3280 W kg−1.

Iron-cobalt phosphide/nitrogen-doped carbon composite derived from prussian blue analogues as anode materials for sodium-ion batteries

Transition metal phosphides (TMPs) are recognized as attractive substitutes for lithium/sodium storage owing to their notable capacity and outstanding safety features. However, they face significant challenges in applications, particularly poor cycling stability and rapid capacity decay. In this study, we report a simple strategy utilizing dopamine-coated Prussian blue analogues as precursors to prepare bimetallic iron‑cobalt phosphide/nitrogen-doped carbon (Fe1-xCoxP/NC) composite materials via a one-step carbothermal phosphorization process. Benefiting from their nanostructured advantages and electronic interactions between Fe and Co sites, Fe0.17Co0.83P/NC, prepared by adjusting and optimizing the ion ratio, exhibits excellent rate capability and cycling performance as an anode material for sodium-ion batteries. It achieves a high specific capacity of 505.6 mAh g−1 at 0.5 A g−1. Even after 1000 cycles at a high current of 1 A g−1, the reversible specific capacity remains at 413.6 mAh g−1. Ex-situ XRD studies confirm that Fe0.17Co0.83P/NC stores Na+ via a conversion mechanism, where the crystalline CoP phase transforms into Na3P phase during the discharging process.

Hybrid of sub-1 nm single-dispersed polyoxometalate and reduced graphene oxide as advanced anodes for durable sodium-ion batteries

Polyoxometalates (POMs) are widely thought as promising choices for sodium-ion batteries (SIBs) because of their refined molecular structures and excellent reversible multielectron charge-discharge behaviors. Nevertheless, the POMs anion clusters could dissolve in the electrolyte when attacked by solvent molecules, thus reducing active sites and affecting the actual performance of these POMs-based electrodes. Herein, we report the development of a new type of electrode system that produces single-dispersed POMs molecular cluster/polydopamine/reduced graphene oxide composites ({PMo12}/PDA@rGO) through a self-assembly method. PDA acts as the role of “killing two birds with one stone”. It not only works as the linker to promote the formation of stable and uniform monodisperse {PMo12} clusters on the rGO surface, but also prevents the POMs from desorbing and dissolving upon deep cycling test. As a consequence, when used as the anode material for SIBs, the obtained {PMo12}/PDA@rGO exhibits an admirable long-term cycling performance, for instance, it holds a high Na-storage capacity of 277.5 mAh g−1 with an average Coulomb efficiency up to 99.89 % over 2000 cycles at 1 A g−1. This work offers versatile possibilities for designing POMs-based composites and provides new insight into developing single dispersed POMs for advanced SIBs.

Revealing the potential of a C6BN/black phosphorene nanocomposite as an anode material for sodium-ion batteries by atomistic simulation: DFT and AIMD

Black phosphorus (BP) has recently been regarded as a promising anode for sodium-ion batteries (SIBs) owing to its high storage capacity, rapid Na mobility in its lamellar structure, and low redox potential. However, its poor cyclability due to structural instability hampers its further implementation in SIBs. Here, we propose to design a novel two-dimensional nanocomposite by vertically stacking a C6BN sheet on a black phosphorene layer (C6BN/Black-Pn). Atomistic simulations by the van der Waals corrected density functional theory method were conducted to assess the suitability of the designed C6BN/Black-Pn model as a potential anode in SIBs. Benefiting from C6BN's electronic and chemical features, Black-Pn's band gap in C6BN/Black-Pn is diminished to 0.14 eV, which disappears and indicates metallic character upon sodiation. Additionally, the optimized Na adsorption energy within the nanocomposite is decreased to −2.06 eV, compared to −1.76 eV in pure Black-Pn and −0.98 eV in C6BN, with a modest diffusion barrier of 0.23 eV. A maximal theoretical capacity of 568.77 mAh/g and a low potential of 0.48 V are predicted for the nanocomposite. The above evaluation of C6BN/Black-Pn electrode for SIBs may provide better insights into adopting a physical approach to address BP electrochemical failures for advanced energy storage.

DFT-D study of carbon-doped β12 borophene as a desirable anode material for sodium-ion batteries

In the quest for the elaboration of advanced energy storage systems (EESs), sodium-ion batteries (SIBs) have emerged as a hopeful alternative to their lithium-ion counterparts, owing to the abundant availability of sodium. This article delves into the utilization of carbon-doped β12 borophene as an anode material for SIBs using density functional theory (DFT) calculations. Based on the band structure calculations, the metallic electronic character of this structure facilitates rapid electron transfer, contributing to its superior performance. Moreover, the remarkably low-energy barrier of 0.066–0.328 eV for migration ensures efficient sodium ion transport, which is critical for new fast-charge technology and better charge/discharge performance. Our investigation reveals that carbon-doped β12 Borophene’s two-dimensional structure, high electrical conductivity, and theoretical capacity of 1972 mAh g−1 make it an ideal candidate for SIB anodes, offering a new avenue for the development of low cost and high-capacity energy storage solutions.

Colloidally synthesized Cu3VS4 nanocrystals as a long cycling anode material for sodium-ion batteries

We report on the colloidal synthesis of Cu3VS4 nanocrystals as an earth abundant anode material for sodium-ion battery applications. The nanocrystals were structurally characterized prior to testing in half-cells, where they displayed excellent cycling stability up to 1000 cycles, demonstrating the potential of colloidally synthesised materials for sustainable battery applications.

Defects introducing and heterostructures engineering synergistically constructing active sites for achieving stable and fast ion transport in sodium-ion batteries

Bronze phase TiO2 (TiO2(B)) has attracted significant interest as potential anode materials for sodium-ion batteries (SIBs) due to its distinctive open tunnel structure, offering abundant insertion sites for Na+-ions. However, the practical application has been hindered by its poor electrical conductivity and insufficient Na+ diffusion kinetics. Herein, we propose a novel strategy that integrates defect introducing and heterostructures engineering to enhance the performance of TiO2(B) anode. Specifically, we aim to induce oxygen vacancies (OVs) into TiO2(B) through N-doping and in-situ growth on MXenes nanosheets, thereby fabricating N-doped TiO2(B)/MXenes (N-TiO-MX) heterostructures. This strategy leverages the synergistic effects of OVs and N-atoms, along with the formation of heterointerfaces, to effectively reduce the bandgap, increase the number of Na+-ion storage sites, and shorten ion diffusion distances. The robust coupling between TiO2(B) and MXenes ensures the structural integrity of N-TiO-MX heterostructures. Consequently, the N-TiO-MX exhibits a high specific capacity of 211.3 mAh g−1 at 0.1 A g−1 after 400 cycles and superior cycling stability with 163.1 mAh g−1 after 1000 cycles at 1.0 A g−1. The study provides unique insights for designing heterostructure materials to achieve high capacity and excellent fast-charging capability.

Ab Initio Prediction of Two-Dimensional GeSiBi2 Monolayer as Potential Anode Materials for Sodium-Ion Batteries.

The conceptualization and deployment of electrode materials for rechargeable sodium-ion batteries are key concerns for next-generation energy storage systems. In this contribution, the configuration stability of single-layer GeSiBi2 is systematically discussed based on first-principles calculations, and its potential as an anode material is further investigated. It is demonstrated that the phonon spectrum confirms the dynamic stability and the adsorption energy identifies a strong interaction between Na atoms and the substrate material. The electronic bands indicative of inherent metallicity contribute to the enhancement of electronic conductivity after Na adsorption. The multilayer adsorption of Na provides a theoretical capacity of 361.7 mAh/g, which is comparable to that of other representative two-dimensional anode materials. Moreover, the low diffusion barriers of 0.19 and 0.15 eV further guarantee the fast diffusion kinetics. These contributions signal that GeSiBi2 can be a compatible candidate for sodium-ion batteries anodes.

Efficient Sodium Storage in Cu1.96S@NC Anode Achieved by Robust S─C Bonds and Current Collector Self-Induced Forming Cu2S Quantum Dots.

Transition metal sulfides are investigation hotspots of anode material for sodium-ion batteries (SIBs) due to their structural diversity and high storage capacity. However, they are still plagued by inevitable volume expansion during sodiation/desodiation and an unclear energy storage mechanism. Herein, a one-step sulfidation-carbonization strategy is proposed for in situ confined growth of Cu1.96S nanoparticles in nitrogen-doped carbon (Cu1.96S@NC) using octahedral metal-organic framework (Cu-BTC) as a precursor and investigate the driving effect of Cu current collector on its sodium storage. The generation of S─C bonds in Cu1.96S@NC avoids the volume change and structural collapse of Cu1.96S nanoparticles during the cycling process and improves the adsorption and transport capacity of the material for Na+. More exciting, the Cu species in the Cu current collector are self-induced forming Cu2S quantum dots to enter the original anode material during the initial few charging and discharging cycles, which unique small-size effect and abundant edge-active sites enhance the energy storage capacity of Cu1.96S. Thus, the Cu1.96S@NC exhibits a superior first discharge capacity of 608.56 mAh g-1 at 0.2 A g-1 with an initial Coulomb efficiency (ICE) of 75.4%, as well as provides excellent rate performance and long cycle durability up to 2000 cycles.

BC6NA monolayer as an ideal anode material for high-performance sodium-ion batteries

Selecting an appropriate anode material (AM) has been considered to be a crucial initial step in advancing high-performance batteries. Within this piece of research, we examine the suitability of the BC6NA monolayer (referred to as BC6NAML) as an AM by first-principles calculations. The BC6NAML exhibits metallic behavior consistently, even with varying concentrations of Na atoms, making it an ideal choice for battery usages. Our findings revealed that the theoretical storage capacity for Na-adhered BC6NAML was 406.36 mAhg−1, surpassing graphite, TiO2, BC6NA, and numerous other 2D materials. The BC6NAML also demonstrates a diffusion barrier of 0.39 eV and favorable diffusivity of Na-ions. Although the open-circuit voltage (OCV) of BC6NAML was temperate and lower compared to the OCV of other AMs like TiO2, our results suggested that it is possible to utilize BC6NAML as one of the encouraging host materials for sodium-ion batteries (SIBs). Consequently, this investigation into the potential anodic application of BC6NAML proves valuable for future experimental studies into sodium storage for SIBs.

Azatriangulenetrione as the Anode Material for Sodium-Ion Batteries: Reversible Redox Chemistry Mediated by Lone Pair Electrons.

Redox-active organic molecules have potential as electrode materials, but their cycling stability is often limited by the irreversible formation of σ-bonds from the radical intermediates. Herein, we present an effective approach to achieve high reversibility by using lone pair electrons to mediate intramolecular radical-radical coupling. Azatriangulenetrione (1) was examined as the anode in sodium-ion batteries, which displayed a reversible four-step, one-electron redox chemistry. In situ electron spin resonance, ex situ Fourier transform infrared/X-ray photoelectron spectroscopy, and density functional theory calculation revealed that the unstable radical anions can couple with each other through the lone pair electrons of the central nitrogen atom, leading to stabilized radical species. Furthermore, scan-rate-dependent cyclic voltammetry measurements and galvanostatic intermittent titration techniques demonstrated that the redox reaction kinetics for radical formation were much faster than the radical paring process. This study offers deep insights into the design of highly reversible organic electrodes.

Sub-minute carbonization of polymer/carbon nanotube films by microwave induction heating for ultrafast preparation of hard carbon anodes for sodium-ion batteries

Hard carbons (HCs) are excellent anode materials for sodium-ion batteries (SIBs). However, the carbonization and granulation of HC powders involve complex processes and require considerable energy. Here, we developed a facile method for manufacturing HC anodes for SIBs via a novel microwave induction heating (MIH) process for polymer/single-walled carbon nanotube (SWCNT) films. Numerical simulations solving electromagnetic field and heat transfer problems revealed the MIH mechanism; the electric current induced by the applied microwave enables direct Joule heating of the SWCNT networks in the composite film. Consequently, the composite films could be heated to the target temperatures (800–1400 °C) and free-standing HC/SWCNT anodes could be prepared by applying MIH for only 30 s. Comparative analyses confirmed that ultrafast MIH is a reliable technique for producing HC anodes and can replace conventional carbonization processes which require a high-temperature furnace. Moreover, the HC/SWCNT anodes prepared by the ultrafast MIH were successfully applied to the SIB full cells. Finally, the feasibility of MIH for scalable roll-to-roll production of HC anodes was verified through local heating tests using a circular sheet larger than a resonator.

Heterogeneous carbon coated resin-based hard carbon anode material for high-performance sodium ion batteries

Resin-based hard carbons are promising anode materials for sodium ion batteries (SIBs) due to their high storage capacity and purity. However, the low initial coulombic efficiency (ICE) still hinders their practical application. Crosslinking and high-temperature pyrolysis strategies have been demonstrated to improve ICE effectively, but the complex process and high energy consumption hinder their industrialization. This paper proposes a facile synthesis of resin-based hard carbon with a soft carbon coating strategy to improve ICE. By carbonizing commercial phenolic resin at 1150℃, hard carbon with a reversible capacity of 291.6 mAh g−1 and 82.6 % ICE was obtained. After asphalt-based soft carbon coating, the optimized sample (CHC-1150) with a heterogeneous carbon coating layer of about 8.5 nm displays a high reversible capacity and ICE of 309.8 mAh g−1 and 88.2 %. Moreover, when combined with NaFe1/3Ni1/3Mn1/3O2 cathode, the assembled 18650 cylindrical-type batteries deliver a high ICE of 84.3 %, excellent low-temperature capability and cycling stability. Additionally, the disassembly results after cycling indicate that the soft carbon layer can inhibit the decomposition of electrolytes and avoid sodium plating. These encouraging results suggest that heterogeneous carbon coating should be a promising strategy to promote the electrochemical performance of resin-based hard carbon anode materials for SIBs.

Sustainable conversion of vine shoots and pig manure into high-performance anode materials for sodium-ion batteries

Sodium-ion batteries (SIBs) are considered promising candidates for future grid energy storage, with hard carbons emerging as key commercial anode materials. This study presents a novel approach to synthesize N-doped hard carbons via co-hydrothermal treatment of vine shoots and pig manure and subsequent thermal annealing of the resulting hydrochar. This method enhances the development of micro- and ultra-microporosity in the synthesized hard carbons, with nitrogen, and to a lesser extent phosphorus and sulfur, introduced as doping elements. Furthermore, the incorporation of hydrochloric acid during the hydrothermal step promotes biomass hydrolysis, leading to increased mesoporosity and the formation of microsphere clusters. In the realm of electrochemical performance, an investigation into various ester- and ether-based electrolytes has revealed NaPF6 in diglyme as the best formulation, thanks to its thinner and more stable solid electrolyte interface (SEI). Using this electrolyte, the best-performing electrode showed an initial Coulombic efficiency (ICE) of 73 %, with reversible capacities of 239, 180, 86, and 57 mAh g−1 at 0.1, 1, 5, and 10 A g−1, respectively. In addition, the electrode exhibited a remarkable capacity retention of 88 % after 250 cycles as well as a compatible behavior when paired with a NVPF-based cathode.