Preparation of novel two-stage structure MnO micrometer particles as lithium-ion battery anode materials

MnO micrometer particles with a two-stage structure (composed of mass nanoparticles) were produced via a one-step hydrothermal method using histidine and potassium permanganate (KMnO₄) as reagents, with subsequent calcination in a nitrogen (N₂) atmosphere. When the MnO micrometer particles were utilized in lithium-ion batteries (LIBs) as anode materials, the electrode showed a high reversible specific capacity of 747 mA h g⁻¹ at 100 mA g⁻¹ after 100 cycles, meanwhile, the electrode presented excellent rate capability at various current densities from 100 to 2000 mA g⁻¹ (∼203 mA h g⁻¹ at 2000 mA g⁻¹). This study developed a new approach to prepare two-stage structure micrometer MnO particles and the sample can be a promising anode material for lithium-ion batteries.

MnO micrometer particles with a two-stage structure (composed of mass nanoparticles) were produced via a one-step hydrothermal method using histidine and potassium permanganate (KMnO₄) as reagents, with subsequent calcination in a nitrogen (N₂) atmosphere.     

Design and synthesis of graphene/SnO2/polyacrylamide nanocomposites as anode material for lithium-ion batteries

Tin dioxide (SnO₂) is a promising anode material for lithium-ion batteries owing to its large theoretical capacity (1494 mA h g⁻¹). However, its practical application is hindered by these problems: the low conductivity, which restricts rate performance of the electrode, and the drastic volume change (400%). In this study, we designed a novel polyacrylamide/SnO₂ nanocrystals/graphene gel (PAAm@SnO₂NC@GG) structure, in which SnO₂ nanocrystals anchored in three-dimensional graphene gel network and the polyacrylamide layers could effectively prevent the agglomeration of SnO₂ nanocrystals, presenting excellent cyclability and rate performance. A capacity retention of over 90% after 300 cycles of 376 mA h g⁻¹ was achieved at a current density of 5 A g⁻¹. In addition, a stable capacity of about 989 mA h g⁻¹ at lower current density of 0.2 A g⁻¹ was achieved.

Tin dioxide (SnO₂) is a promising anode material for lithium-ion batteries owing to its large theoretical capacity (1494 mA h g⁻¹).     

Preparation of cobalt sulfide@reduced graphene oxide nanocomposites with outstanding electrochemical behavior for lithium-ion batteries

Cobalt sulfide@reduced graphene oxide composites were prepared through a simple solvothermal method. The cobalt sulfide@reduced graphene oxide composites are composed of cobalt sulfide nanoparticles uniformly attached on both sides of reduced graphene oxide. Some favorable electrochemical performances in specific capacity, cycling performance, and rate capability are achieved using the porous nanocomposites as an anode for lithium-ion batteries. In a half-cell, it exhibits a high specific capacity of 1253.9 mA h g⁻¹ at 500 mA g⁻¹ after 100 cycles. A full cell consists of the cobalt sulfide@reduced graphene oxide nanocomposite anode and a commercial LiCoO₂ cathode, and is able to hold a high capacity of 574.7 mA h g⁻¹ at 200 mA g⁻¹ after 200 cycles. The reduced graphene oxide plays a key role in enhancing the electrical conductivity of the electrode materials; and it effectively prevents the cobalt sulfide nanoparticles from dropping off the electrode and buffers the volume variation during the discharge–charge process. The cobalt sulfide@reduced graphene oxide nanocomposites present great potential to be a promising anode material for lithium-ion batteries.

Cobalt sulfide@reduced graphene oxide nanocomposites obtained through a dipping and hydrothermal process, exhibit ascendant lithium-ion storage properties.     

An investigation of Li2TiO3–coke composite anode material for Li-ion batteries

Anode material Li₂TiO₃–coke was prepared and tested for lithium-ion batteries. The as-prepared material exhibits excellent cycling stability and outstanding rate performance. Charge/discharge capacities of 266 mA h g⁻¹ at 0.100 A g⁻¹ and 200 mA h g⁻¹ at 1.000 A g⁻¹ are reached for Li₂TiO₃–coke. A cycling life-time test shows that Li₂TiO₃–coke gives a specific capacity of 264 mA h g⁻¹ at 0.300 A g⁻¹ and a capacity retention of 92% after 1000 cycles of charge/discharge.

Anode material Li₂TiO₃–coke was prepared and tested for lithium-ion batteries. The as-prepared material exhibits excellent cycling stability and outstanding rate performance.     

In situ production of a two-dimensional molybdenum disulfide/graphene hybrid nanosheet anode for lithium-ion batteries

A solvent-free, low-cost, high-yield and scalable single-step ball milling process is developed to construct 2D MoS₂/graphene hybrid electrodes for lithium-ion batteries. Electron microscopy investigation reveals that the obtained hybrid electrodes consist of numerous nanosheets of MoS₂ and graphene which are randomly distributed. The MoS₂/graphene hybrid anodes exhibit excellent cycling stability with high reversible capacities (442 mA h g⁻¹ for MoS₂/graphene (40 h); 553 mA h g⁻¹ for MoS₂/graphene (20 h); 342 mA h g⁻¹ for MoS₂/graphene (10 h)) at a high current rate of 250 mA g⁻¹ after 100 cycles, whereas the pristine MoS₂ electrode shows huge capacity fading with a retention of 37 mA h g⁻¹ at 250 mA g⁻¹ current after 100 cycles. The incorporation of graphene into MoS₂ has an extraordinary effect on its electrochemical performance. This work emphasises the importance of the construction of the 2D MoS₂/graphene hybrid structure to prevent capacity fading issues with the MoS₂ anode in lithium-ion batteries.

A solvent-free, low-cost, high-yield and scalable single-step ball milling process is developed to construct 2D MoS₂/graphene hybrid electrodes for lithium-ion batteries.     

Highly crystalline nickel hexacyanoferrate as a long-life cathode material for sodium-ion batteries

Prussian blue analogs (PBAs) are attractive cathode candidates for high energy density, including long life-cycle rechargeable batteries, due to their non-toxicity, facile synthesis techniques and low cost. Nevertheless, traditionally synthesized PBAs tend to have a flawed crystal structure with a large amount of [Fe(CN)₆]⁴⁻ openings and the presence of crystal water in the framework; therefore the specific capacity achieved has continuously been low with poor cycling stability. Herein, we demonstrate low-defect and sodium-enriched nickel hexacyanoferrate nanocrystals synthesized by a facile low-speed co-precipitation technique assisted by a chelating agent to overcome these problems. As a consequence, the prepared high-quality nickel hexacyanoferrate (HQ-NiHCF) exhibited a high specific capacity of 80 mA h g⁻¹ at 15 mA g⁻¹ (with a theoretical capacity of ∼85 mA h g⁻¹), maintaining a notable cycling stability (78 mA h g⁻¹ at 170 mA g⁻¹ current density) without noticeable fading in capacity retention after 1200 cycles. This low-speed synthesis strategy for PBA-based electrode materials could be also extended to other energy storage materials to fabricate high-performance rechargeable batteries.

A low-speed synthesis strategy was designed to fabricate Prussian blue analog based electrode materials for high-performance rechargeable batteries.     

SnS/C nanocomposites for high-performance sodium ion battery anodes

Sodium-ion batteries have been considered as one of the most promising types of batteries, beyond lithium-ion batteries, for large-scale energy storage applications. However, their deployment hinges on the development of new anode materials, since it has been shown that many important anode materials employed in lithium ion batteries, such as graphite and silicon, are inadequate for sodium-ion batteries. We have simply prepared novel SnS/C nanocomposites through a top-down approach as anode materials for sodium-ion batteries. Their electrochemical performance has been significantly improved when compared to bare SnS, especially in terms of cycling stability and rate capabilities. SnS/C nanocomposites exhibit excellent capacity retention, at various current rates, and deliver capacities as high as 400 mA h g⁻¹ even at the high current density of 800 mA g⁻¹ (2C). Ex situ transmission electron microscopy, X-ray diffraction and operando X-ray absorption near edge structure studies have been performed in order to unravel the reaction mechanism of the SnS/C nanocomposites.

SnS/C nanocomposites were simply prepared as anode materials for sodium-ion batteries. They showed excellent cycling stability at various current densities with more than 90% of its capacity delivered when the current increased from 50 to 500 mA g⁻¹.     

Facile synthesis of perovskite CeMnO3 nanofibers as an anode material for high performance lithium-ion batteries

A facile synthesis of perovskite-type CeMnO₃ nanofibers as a high performance anode material for lithium-ion batteries was demonstrated. The nanofibers were prepared by the electrospinning technique. The characterization of CeMnO₃ nanofibers was carried out by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy. SEM images manifested nanofibers with a diameter of 470 nm having a rough surface with a porous structure. TEM images were consistent with the observations from the SEM images. The electrochemical properties of CeMnO₃ perovskite in lithium-ion batteries were investigated. The CeMnO₃ anode exhibited a discharge capacity of 2159 mA h g⁻¹ with a coulombic efficiency of 93.79%. In addition, a high cycle stability and a capacity of 276 mA h g⁻¹ at the current density of 1000 mA g⁻¹ can be effectively maintained due to the high Li⁺ conductivity in the CeMnO₃ anode. This study could provide an efficient and potential application of perovskite-type CeMnO₃ nanofibers in lithium-ion batteries.

A facile synthesis of perovskite-type CeMnO₃ nanofibers as a high performance anode material for lithium-ion batteries was demonstrated.     

Structure and conductivity enhanced treble-shelled porous silicon as an anode for high-performance lithium-ion batteries

Silicon is regarded as the next generation anode material for lithium-ion batteries because of its high specific capacity, low intercalation potential and abundant reserves. However, huge volume changes during the lithiation and delithiation processes and low electrical conductivity obstruct the practical applications of silicon anodes. In this study, a treble-shelled porous silicon (TS-P-Si) structure was synthesized via a three-step approach. The TS-P-Si anode delivered a capacity of 858.94 mA h g⁻¹ and a capacity retention of 87.8% (753.99 mA h g⁻¹) after being subjected to 400 cycles at a current density of 400 mA g⁻¹. The good cycling performance was due to the unique structure of the inner silicon oxide layer, middle silver nano-particle layer and outer carbon layer, leading to a good conductivity and a decreased volume change of this silicon-based anode.

In this paper, a treble-shelled porous silicon structure is synthesized through three-step approach to enhance the structural stability and conductivity.     

Construction of 1T@2H MoS2 heterostructures in situ from natural molybdenite with enhanced electrochemical performance for lithium-ion batteries

Natural molybdenite, an inexpensive and naturally abundant material, can be directly used as an anode material for lithium-ion batteries. However, how to release the intrinsic capacity of natural molybdenite to achieve high rate performance and high capacity is still a challenge. Herein, we introduce an innovative, effective, and one-step approach to preparing a type of heterostructure material containing 1T@2H MoS₂ crafted from insertion and expansion of natural molybdenite. The metallic 1T phase formed in situ can significantly improve the electronic conductivity of MoS₂. At the same time, 1T@2H MoS₂ heterostructures can provide an internal electric field (E-field) to accelerate the migration rate of electrons and ions, promote the charge transfer behaviour, and ensure the reaction reversibility and lithium storage kinetics. Such worm-like 1T@2H MoS₂ heterostructures also have a large specific surface area and a large number of defects, which will help shorten the lithium-ion transmission distance and provide more ion transmission channels. As a result, it exhibits a discharge capacity of 788 mA h g⁻¹ remarkably at 100 mA g⁻¹ after 485 cycles and stable cycling performance. It also shows excellent magnification performance of 727 mA h g⁻¹ at 1 A g⁻¹, compared to molybdenite concentrate. Briefly, this work''s heterostructure architectures open up a new avenue for applying natural molybdenite in lithium-ion batteries, which has the potential to achieve large-scale commercial applications.

Natural molybdenite, an inexpensive and naturally abundant material, can be directly used as an anode material for lithium-ion batteries.     

Self-supporting V2O5 nanofiber-based electrodes for magnesium–lithium-ion hybrid batteries

The increasing demand for high energy, sustainable and safer rechargeable electrochemical storage systems for portable devices and electric vehicles can be satisfied by the use of hybrid batteries. Hybrid batteries, such as magnesium–lithium-ion batteries (MLIBs), using a dual-salt electrolyte take advantage of both the fast Li⁺ intercalation kinetics of lithium-ion batteries (LIBs) and the dendrite-free anode reactions. Here we report the utilization of a binder-free and self-supporting V₂O₅ nanofiber-based cathode for MLIBs. The V₂O₅ cathode has a high operating voltage of ∼1.5 V vs. Mg/Mg²⁺ and achieves storage capacities of up to 386 mA h g⁻¹, accompanied by an energy density of 280 W h kg⁻¹. Additionally, a good cycling stability at 200 mA g⁻¹ over 500 cycles is reached. The structural integrity of the V₂O₅ cathode is preserved upon cycling. This work demonstrates the suitability of the V₂O₅ cathode for MLIBs to overcome the limitations of LIBs and MIBs and to meet the future demands of advanced electrochemical storage systems.

This work shows the feasibility of a self-supporting V₂O₅ nanofiber-based cathode for magnesium–lithium-ion batteries reaching an energy density of 280 W h kg⁻¹.     

Rationally designed hierarchical porous CNFs/Co3O4 nanofiber-based anode for realizing high lithium ion storage

To achieve a high power density of lithium-ion batteries, it is essential to develop anode materials with high capacity and excellent stability. Cobalt oxide (Co₃O₄) is a prospective anode material on account of its high energy density. However, the poor electrical conductivity and volumetric changes of the active material induce a dramatic decrease in capacity during cycling. Herein, a hierarchical porous hybrid nanofiber of ZIF-derived Co₃O₄ and continuous carbon nanofibers (CNFs) is rationally constructed and utilized as an anode material for lithium-ion batteries. The PAN/ZIF-67 heterostructure composite nanofibers were first synthesized using electrospinning technology followed by the in situ growth method, and then the CNFs/Co₃O₄ nanofibers were obtained by subsequent multi-step thermal treatment. The continuous porous conductive carbon backbone not only effectively provides a channel to expedite lithium ion diffusion and electrode transfer, but also accommodates volume change of Co₃O₄ during the charge–discharge cycling process. The electrode exhibits a high discharge capacity of 1352 mA h g⁻¹ after 500 cycles at a constant current density of 0.2 A g⁻¹. Additionally, the composites deliver a discharge capacity of 661 mA h g⁻¹ with a small capacity decay of 0.078% per cycle at a high current density of 2 A g⁻¹ after 500 cycles. This hierarchical porous structural design presents an effective strategy to develop a hybrid nanofiber for improving lithium ion storage.

Hierarchical porous CNFs/Co₃O₄ nanofiber is rationally designed and constructed as an anode for achieving high capacity and stable lithium ion batteries.     

Preparation and lithium storage of core–shell honeycomb-like Co3O4@C microspheres

Core–shell honeycomb-like Co₃O₄@C microspheres were synthesized via a facile solvothermal method and subsequent annealing treatment under an argon atmosphere. Owing to the core–shell honeycomb-like structure, a long cycling life was achieved (a high reversible specific capacity of 318.9 mA h g⁻¹ was maintained at 5C after 1000 cycles). Benefiting from the coated carbon layers, excellent rate capability was realized (a reversible specific capacity as high as 332.6 mA h g⁻¹ was still retained at 10C). The design of core–shell honeycomb-like microspheres provides a new idea for the development of anode materials for high-performance lithium-ion batteries.

The reversible specific capacity of CSHCo₃O₄@C microspheres was as high as 332.6 mA h g⁻¹ at 10C, which was significantly higher than that of SCo₃O₄ microspheres (68.7 mA h g⁻¹).     

Large-scale synthesis of ultrafine Fe3C nanoparticles embedded in mesoporous carbon nanosheets for high-rate lithium storage

Fe₃C modified by the incorporation of carbon materials offers excellent electrical conductivity and interfacial lithium storage, making it attractive as an anode material in lithium-ion batteries. In this work, we describe a time- and energy-saving approach for the large-scale preparation of Fe₃C nanoparticles embedded in mesoporous carbon nanosheets (Fe₃C-NPs@MCNSs) by solution combustion synthesis and subsequent carbothermal reduction. Fe₃C nanoparticles with a diameter of ∼5 nm were highly crystallized and compactly dispersed in mesoporous carbon nanosheets with a pore-size distribution of 3–5 nm. Fe₃C-NPs@MCNSs exhibited remarkable high-rate lithium storage performance with discharge specific capacities of 731, 647, 481, 402 and 363 mA h g⁻¹ at current densities of 0.1, 1, 2, 5 and 10 A g⁻¹, respectively, and when the current density reduced back to 0.1 A g⁻¹ after 45 cycles, the discharge specific capacity could perfectly recover to 737 mA h g⁻¹ without any loss. The unique structure could promote electron and Li-ion transfer, create highly accessible multi-channel reaction sites and buffer volume variation for enhanced cycling and good high-rate lithium storage performance.

Fe₃C modified by the incorporation of carbon materials offers excellent electrical conductivity and interfacial lithium storage, making it attractive as an anode material in lithium-ion batteries.     

Facile in situ growth of ZnO nanosheets standing on Ni foam as binder-free anodes for lithium ion batteries

ZnO has attracted increasing attention as an anode for lithium ion batteries. However, the application of such anode materials remains restricted by their poor conductivity and large volume changes during the charge/discharge process. Herein, we report a simple hydrothermal method to synthesize ZnO nanosheets with a large surface area standing on a Ni foam framework, which is applied as a binder-free anode for lithium ion batteries. ZnO nanosheets were grown in situ on Ni foam, resulting in enhanced conductivity and enough space to buffer the volume changes of the battery. The ZnO nanosheets@Ni foam anode showed a high specific capacity (1507 mA h g⁻¹ at 0.2 A g⁻¹), good capacity retention (1292 mA h g⁻¹ after 45 cycles), and superior rate capacity, which are better than those of ZnO nanomaterial-based anodes reported previously. Moreover, other transition metal oxides, such as Fe₂O₃ and NiO were also formed in situ on Ni foam with perfect standing nanosheets structures by this hydrothermal method, confirming the universality and efficiency of this synthetic route.

ZnO nanosheets@Ni foam anode showed a high specific capacity, good capacity retention and superior rate capacity. Moreover, other transition metal oxides were also similarly formed on Ni foam, confirming the universality and efficiency of the synthetic route.     

Hydrothermal-template synthesis and electrochemical properties of Co3O4/nitrogen-doped hemisphere-porous graphene composites with 3D heterogeneous structure

Despite the high capacity of Co₃O₄ employed in lithium-ion battery anodes, the reduced conductivity and grievous volume change of Co₃O₄ during long cycling of insertion/extraction of lithium-ions remain a challenge. Herein, an optimized nanocomposite, Co₃O₄/nitrogen-doped hemisphere-porous graphene composite (Co₃O₄/N-HPGC), is synthesized by a facile hydrothermal-template approach with polystyrene (PS) microspheres as a template. The characterization results demonstrate that Co₃O₄ nanoparticles are densely anchored onto graphene layers, nitrogen elements are successfully introduced by carbamide and the nanocomposites maintain the hemispherical porous structure. As an anode material for lithium-ion batteries, the composite material not only maintains a relatively high lithium storage capacity (the first discharge specific capacity can reach 2696 mA h g⁻¹), but also shows significantly improved rate performance (1188 mA h g⁻¹ at 0.1 A g⁻¹, 344 mA h g⁻¹ at 5 A g⁻¹) and enhanced cycling stability (683 mA h g⁻¹ after 500 cycles at 1 A g⁻¹). The enhanced electrochemical properties of Co₃O₄/N-HPGC nanocomposites can be ascribed to the synergistic effects of Co₃O₄ nanoparticles, novel hierarchical structure with hemisphere-pores and nitrogen-containing functional groups of the nanomaterials. Therefore, the developed strategy can be extended as a universal and scalable approach for integrating various metal oxides into graphene-based materials for energy storage and conversion applications.

The Co₃O₄/N-HPGC nanocomposites synthesized by a hydrothermal-template approach with polystyrene microspheres as the template possess excellent electrochemical performance.     

Zinc vacancy modulated quaternary metallic oxynitride GeZn1.7ON1.8: as a high-performance anode for lithium-ion storage

The development of alternative anode materials to achieve high lithium-ion storage performance is crucial for the next-generation lithium-ion batteries (LIBs). In this study, a new anode material, Zn-defected GeZn_1.7ON_1.8 (GeZn_1.7−xON_1.8), was rationally designed and successfully synthesized by a simple ammoniation and acid etching method. The introduced zinc vacancy can increase the capacity by more than 100%, originating from the additional space for the lithium-ion insertion. This GeZn_1.7−xON_1.8 particle anode delivers a high capacity (868 mA h g⁻¹ at 0.1 A g⁻¹ after 200 cycles) and ultralong cyclic stability (2000 cycles at 1.0 A g⁻¹ with a maintained capacity of 458.6 mA h g⁻¹). Electrochemical kinetic analysis corroborates the enhanced pseudocapacitive contribution and lithium-ion reaction kinetics in the GeZn_1.7−xON_1.8 particle anode. Furthermore, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses at different electrochemical reaction states confirm the reversible intercalation lithium-ion storage mechanism of this GeZn_1.7−xON_1.8 particle anode. This study offers a new vision toward designing high-performance quaternary metallic oxynitride-based materials for large-scale energy storage applications.

Zn-defected GeZn_1.7ON_1.8 (GeZn_1.7−xON_1.8) was successfully synthesized by a simple ammoniation and acid etching method. This well-designed Zn cation-deficient GeZn_1.7−xON_1.8 anode shows enhanced lithium-ion storage performance.     

Sb2O3 nanoparticles anchored on N-doped graphene nanoribbons as improved anode for 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. Still, major drawbacks for the commercial application of SIBs lie in the slow kinetic processes and poor cycling performance of the devices. In this work, a hybrid nanocomposite of Sb₂O₃ nanoparticles anchored on N-doped graphene nanoribbons (GNR) is implemented as anode material in SIBs. The obtained Sb₂O₃/N-GNR anode delivers a reversible specific capacity of 642 mA h g⁻¹ after 100 cycles at 0.1 A g⁻¹ and exhibits a good rate capability. Even after 500 cycles at 5 A g⁻¹, the specific capacity is maintained at about 405 mA h g⁻¹. Such good Na storage performance is mainly ascribed to the beneficial effect of N doping for charge transfer and to the improved microstructure that facilitates the Na⁺ diffusion through the overall electrode.

A hybrid nanocomposite of Sb₂O₃ nanoparticles anchored on N-doped graphene nanoribbons is used as anode in SIBs. These hybrid electrodes demonstrate a high charge transfer and improved microstructure, facilitating the Na⁺ diffusion in the electrode.     

Ultrafast-charging and long cycle-life anode materials of TiO2-bronze/nitrogen-doped graphene nanocomposites for high-performance lithium-ion batteries

Emerging technologies demand a new generation of lithium-ion batteries that are high in power density, fast-charging, safe to use, and have long cycle lives. This work reports charging rates and specific capacities of TiO₂(B)/N-doped graphene (TNG) composites. The TNG composites were prepared by the hydrothermal method in various reaction times (3, 6, 9, 12, and 24 h), while the N-doped graphene was synthesized using the modified Hummer''s method followed by a heat-treatment process. The different morphologies of TiO₂ dispersed on the N-doped graphene sheet were confirmed as anatase-nanoparticles (3, 6 h), TiO₂(B)-nanotubes (9 h), and TiO₂(B)-nanorods (12, 24 h) by XRD, TEM, and EELS. In electrochemical studies, the best battery performance was obtained with the nanorods TiO₂(B)/N-doped graphene (TNG-24h) electrode, with a relatively high specific capacity of 500 mA h g⁻¹ at 1C (539.5 mA g⁻¹). In long-term cycling, excellent stability was observed. The capacity retention of 150 mA h g⁻¹ was observed after 7000 cycles, at an ultrahigh current of 50C (27.0 A g⁻¹). The synthesized composites have the potential for fast-charging and have high stability, showing potential as an anode material in advanced power batteries for next-generation applications.

The TiO₂-bronze/nitrogen-doped graphene nanocomposites have the potential for fast-charging and have high stability, showing potential as an anode material in advanced power batteries for next-generation applications.     

Preparation of SiO2 nanowire arrays as anode material with enhanced lithium storage performance

SiO₂ nanowire arrays have been prepared by a template-assisted sol gel method and used as a negative electrode material for lithium ion batteries. Amorphous SiO₂ was confirmed by X-ray diffraction and Fourier transform infrared spectroscopy. The results of scanning electron microscopy and transmission electron microscopy confirmed that the SiO₂ nanowire had a diameter of about 100 nm and a length of about 30 μm. Cyclic voltammetry and constant current charge and discharge tests showed the prepared SiO₂ nanowire arrays were electrochemically active at a potential range of 0.05–3.0 V. At a current density of 200 mA g⁻¹, the first discharge specific capacity was as high as 2252.6 mA h g⁻¹ with a coulombic efficiency of 60.7%. Even after about 400 cycles, it still maintained 97.5% of the initial specific capacity. Moreover, a high specific capacity of 315 mA h g⁻¹ was exhibited when the current density was increased to 2500 mA g⁻¹. SiO₂ nanowire array electrodes with high reversible capacity and good cycle performance provide potential anode materials for future lithium-ion batteries.

SiO₂ nanowire arrays were synthesized using an AAO template-assisted sol–gel method. As a lithium negative electrode material, the sample exhibited excellent electrochemical properties.