Improved Lithium Storage Capability Research Articles

Ball-Milling-Triggered Synthesis of Si/C/SiC@MCMB Composites from Carbon Dioxide for Improved Lithium Storage Capability

The excessive emission of carbon dioxide (CO2) poses a serious threat to the sustainable development of human beings. The efficient conversion of CO2 into high-value-added chemicals is of great significance for solving the greenhouse effect and energy crisis. Herein, a new strategy is proposed to turn CO2 into Si/C/SiC composites through a one-step ball-milling reaction with Mg2Si at room temperature. Moreover, mesophase carbon microspheres (MCMB) are introduced into reactants to prepare Si/C/SiC@MCMB composites for possible commercial application. This method realizes the synchronous formation of Si, C, and SiC with a tight interfacial contact at room temperature, which enhances the electronic conductivity and structural stability of Si/C. It is found that the addition of MCMB greatly restricts the formation of SiC inactive phase and leads to a thin lamellar structure for lithium storage. When evaluated as a lithium-ion battery anode, the Si/C/SiC@MCMB composites exhibit superior cycling stability and rating performance. This room temperature synthesis strategy has the advantages of low cost, simple operation process, and easy scalable production, which not only provide a new route to turn CO2 into a benefit but also provide a new way for the design and synthesis of high-capacity Si/C anodes.

Improved Lithium Storage Capability of Si Anode by Ball-Milling Produced Graphitic Carbon Sheet and Fe3O4 Nanoparticles

Improved Lithium Storage Capability of Si Anode by Ball-Milling Produced Graphitic Carbon Sheet and Fe3O4 Nanoparticles

In Situ Construction of a Multifunctional Interface Regulator with Amino-Modified Conjugated Diene toward High-Rate and Long-Cycle Silicon Anodes.

Silicon (Si) is deemed to be the next-generation lithium-ion battery anode. However, on account of the poor electronic conductivity of Si materials and the instability of the solid electrolyte interphase layer, the electrochemical performance of Si anodes is far from reaching the application level. In this work, a multifunctional poly(propargylamine) (PPA) interlayer is constructed on the Si surface via a simple in situ polymerization method. Benefiting from the electronic conductivity, ionic conductivity, robust interphase interactions for hydrogen bonding, and stability of multifunctional PPA, the optimized Si@PPA-7% electrode shows improved lithium storage capability. A high capacity of 1316.3 mAh g-1 is retained after 500 cycles at 2.1 A g-1, and 2370.3 mAh g-1 can be delivered at 42 A g-1, which are in stark contrast to the unmodified Si electrode. Furthermore, the rate and cycle capabilities of the LiFePO4//Si@PPA-7% full cell are also obviously better than those of LiFePO4//Si.

Interface Engineering of Hierarchical MoS2/ZnS/C Heterostructures as Anode Materials for Highly Improved Lithium Storage Capability

Constructing hybrid heterostructures of transition-metal dichalcogenides is an effective strategy to enhance their electrochemical performance and stability as anode materials in lithium-ion batter...

Metal-Organic Frameworks-Derived Mesoporous Si/SiOx @NC Nanospheres as a Long-Lifespan Anode Material for Lithium-Ion Batteries.

Silicon (Si)-based anode materials with suitable engineered nanostructures generally have improved lithium storage capabilities, which provide great promise for the electrochemical performance in lithium-ion batteries (LIBs). Herein, a metal-organic framework (MOF)-derived unique core-shell Si/SiOx @NC structure has been synthesized by a facile magnesio-thermic reduction, in which the Si and SiOx matrix were encapsulated by nitrogen (N)-doped carbon. Importantly, the well-designed nanostructure has enough space to accommodate the volume change during the lithiation/delithiation process. The conductive porous N-doped carbon was optimized through direct carbonization and reduction of SiO2 into Si/SiOx simultaneously. Benefiting from the core-shell structure, the synthesized product exhibited enhanced electrochemical performance as an anode material in LIBs. Particularly, the Si/SiOx @NC-650 anode showed the best reversible capacities up to 724 and 702 mAh g-1 even after 100 cycles. The excellent cycling stability of Si/SiOx @NC-650 may be attributed to the core-shell structure as well as the synergistic effect between the Si/SiOx and MOF-derived N-doped carbon.

Li4Ti5O12/g-C3N4 composite with an improved lithium storage capability

The Li4Ti5O12/graphitic carbon nitride (g-C3N4) composite was fabricated via a solvothermal method followed by heating treatment at 700 °C for 5 h. In this method, g-C3N4 acted as a support to enhance the electronic conductivity of Li4Ti5O12. When tested as anode materials for lithium ion batteries, the as-synthesized Li4Ti5O12/g-C3N4 composite displays a reversible capacity of as high as 150.8 mAh/g with a capacity retention of 86.8% at 0.5 C after 502 cycles. The cycling performance of the composite is enhanced, which could be attributed to the existence of g-C3N4 support.

Synthesis of wolframite FeNbO4 nanorods as a novel anode material for improved lithium storage capability

One-dimensional (1D) FeNbO4 nanorod (ES-FNO) is first synthesized through electrospinning and calcination. ES-FNO is typically composed of a string of homogeneous nanoparticles (about 100 nm in diameter). The lithium diffusion coefficient of ES-FNO is higher than that of bulk sample, because the 1D crystal morphology of ES-FNO provides faster ionic conductivity than the bulk crystals of FeNbO4. ES-FNO delivers the initial specific capacity of 926 mAh g−1 at the current density of 0.1 A g−1 and a much better rate capability than those of bulk FeNbO4. Micron-sized FeNbO4 particles are pulverized and delaminated from the collector of Cu foil, resulting in poor conductivity and loss of capacity. Further X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry (CV) measurements have allowed us to understand the possibility that the redox reaction from Nb5+ to Nb3+ and Fe3+ to Fe0 realized in nanosized FeNbO4.

Template-free synthesis of hierarchical MoO2 multi-shell architectures with improved lithium storage capability

A hierarchical multi-shell structure of MoO2 is synthesized through a template-free one-pot solvothermal method. The relative MoO2 electrode exhibits high reversible specific capacity of 780mAhg−1 after 40cycles, good stability, high capacity retention and improved rate performance in the lithium ion battery application. This material has a unique hierarchical architecture which is a combination of pure hollow structure and core-shell structure. Such a hierarchical multi-shell structure can not only amplify active mass-electrolyte contact area and minimizes lithium ion diffusion path, but also provides a unique interstitial void space to relieve the huge volume change of material. Materials with a hierarchical multi-shell structure are expected to be promising candidates in lithium ion batteries application.

SnO2 nanosheets/g-C3N4 composite with improved lithium storage capabilities

Tin dioxide (SnO2) nanosheets/graphitic carbon nitride (g-C3N4) composite was prepared by a hydrothermal method using mercapto acetic acid as the morphology directing agent in an acidic medium. The as-obtained composite was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscope, and X-ray photoelectron spectroscopy; the results of this study show that in the composite, SnO2 nanosheets with a thickness in the range ∼20–25nm dispersed well on the g-C3N4. The lithium storage capability of the composite was investigated. The cycling performance of the composite was improved and is believed to be attributed by the presence of g-C3N4 support.

Selective crystal facets exposing of dumbbell-like Co3O4 towards high performances anode materials in lithium-ion batteries

In this study, dumbbell-like Co3O4 is obtained via calcination of the prepared spindle-like CoCO3 precursor. The Co3O4 displays high specific surface area of 162.7m2g⿿1 and narrow pore-size-distribution of 3.54nm. When applied as anode material, Co3O4 delivers a specific capacity as high as 1719mAh/g for initial discharge, and retains low discharge capacity loss over 200 cycles at 0.1C conditions. The improved lithium storage capability of the Co3O4 anode can be attributed to high specific surface area and the shortened transport path for Li+ that resulted from specific facet effects.

Controllable synthesis of rod-like SnO2 nanoparticles with tunable length anchored onto graphene nanosheets for improved lithium storage capability

Rod-like SnO2 nanoparticles with tunable length have been anchored onto graphene nanosheets as high performance lithium-ion battery anodes.

Improved Lithium-Storage Capability and Cyclability of Tin Dioxide Confined in Highly Crosslinked Graphene Framework

The dimensional stability of SnO2 nanoparticles during Li+ insertion/de-insertion was improved by confining them within a highly crosslinked graphene framework. The composite was synthesized by reacting an optimal amount of bezene-1,4-diboronic acid (BDBA) with SnO2-anchored graphene oxide (SG) that had a high density of oxygen functionalities. The latter was prepared by irradiating ozone on as-synthesized SG. The resultant composite (SGF) possessed a high boron/carbon ratio and a low fraction of unreacted boronic acid moieties, indicating the production of a highly crosslinked framework. The SGF showed excellent stability with a high capacity when cycled between 0.1 and 3.0 V vs. Li/Li+. A decrease of the low-end potential limit induced instability of the boronic ester linkage, which led to a relatively fast capacity fading. The SGF delivered capacities greater than 940 mAh·g−1 after 150 cycles at 200 mA·g−1, with a fading rate of 1.3 mAh·g−1·cycle−1 (from 2nd to 150th cycles). This was contrasted with 10.4 mAh·g−1·cycle−1 for SGF prepared without ozone-treatment and cycled between 0.01 and 3.0 V vs. Li/Li+. The rate capabilities of SGF were also comparable to or better than those reported previously for SnO2/graphene composites, implying that the highly crosslinked framework does not hamper the electroactivity of SnO2 nanoparticles.

Nanocomposite of Iron Oxide-Reduced Graphene Oxide Applied as High-Performance Anode Materials for Lithium Ion Batteries

: Novel nanostructured iron oxide-reduced graphene oxide composites were synthesized by a facile one-step hydrothermal method in an ethylene glycol (EG)–water system. Different phases of iron oxides were detected by adjusting fabrication parameters including the EG/H2O ratio, base content and iron ions concentration. Electrochemical propertyof fabricated nanocomposites as anode material was examined in a coin–type cell. The high–rate capacity and cycling stability were found, which is attributed to the improved lithium storage capability due to the application of graphene sheet acting as conductive materials for iron oxide nanoparticles. This study provides a favorable approach for exploring the nanocomposites of metal oxide-graphene anode for lithium ion battery applications. Introduction: Currently,α–Fe2O3 has been considered as a promising candidate for lithium ion batteries due to its much higher theoretical capacity of 1350 mAhg‾1 than that of commercial graphite anode materials and its environmental friendly fabrication methods from low–cost resources [1]. In particular, the use of nanomaterials is an effective path to improve rate capabilities of solid state electrodes in batteries attributed to their relatively small diffusion lengths. Furthermore,graphene, with an excellent electronic conductivity, a high theoretical surface area of 2630 m2/g and superior mechanical properties, is a significantly promising component for high performance electrode materials [2]. In this study, an anode material of iron oxide nanoparticles (mainly α–Fe2O3)–reduced graphene oxide for lithium ion battery has been synthesized and reported. Experimental: FeCl3·6H2O (1.08 g) and NaOH (0.8 g) was dissolved in EG (30 ml) by ultrasonication for 1 hour.Then 10 ml deionized water and 15 mg graphene oxide was added to the mixture under stirring to get a homogeneous solution. The solution was transferred into a 50 ml teflon–lined stainless steel autoclave, sealed and heated at 200oC for 10 hours. The product was collected by centrifuging and washed by ethanol and deionized water alternatively for several times, which was followed by drying at 80oC. Morphologies and phases of synthesized nanocomposites were characterized by scanning electron microscopy (SEM), Raman scattering spectroscopy, X-ray diffraction (XRD), high resolution transmission electron microscopy(TEM). Results: Typical XRD pattern of the products was illustrated in Fig.1 that demonstrated the co–existence of α–Fe2O3 and Fe3O4. Diffraction peaks can be indexed to either the rhombohedral phase of α-Fe2O3 (JCPDS NO.84-0307) or the cubic phase of Fe3O4 (JCPDS NO.65-3107). The characteristic peak of graphene oxide located at 10.4° was not found, confirming the formation of graphene. Fig. 1 also showed the SEM image of fabricated iron oxide nanoparticles that were uniform with the diameter about 50 nm, indicating XRD pattern in good agreement with SEM results. Raman spectra also confirmed that the typical features of reduced graphene oxide with the presence of D band (1348 cm−1) and G band (1598 cm−1).

Branch-structured Bi2S3–CNT hybrids with improved lithium storage capability

A hierarchical, branched Bi2S3–CNT hybrid was fabricated through a facile sonochemical approach which exhibited outstanding Li-storage capability.

Layer-stacked tin disulfide nanorods in silica nanoreactors with improved lithium storage capabilities

A new structure of layered materials, layer-stacked nanorod, has been fabricated through an entirely new template-engaged structural transformation methodology. The formation of layer-stacked hexagonal tin disulfide (SnS(2)) nanorods has been demonstrated as an example by using tetragonal tin (Sn) nanorods as sacrificing templates and silica (SiO(2)) as nanoreactors. In addition, the structural transformation process probably involves the formation of orthorhombic tin sulfide (SnS) nanorods as an intermediate product. The rod-like morphology and single-crystal feature of the Sn templates are well preserved in both SnS(2) and SnS products due to the nanoscale confinement in silica. Owing to its unique structural characteristics, the SnS(2)-SiO(2) nanorod anode exhibits excellent capacity retention and improved rate capability, facilitating its application in lithium ion batteries with long cycle life and high power density.

SBA-15 derived carbon-supported SnO2 nanowire arrays with improved lithium storage capabilities

In this work, we report a facile strategy for the synthesis of carbon-supported SnO2 nanowire arrays using SBA-15 nanorods as template. In the first step, molten SnCl2·2H2O is efficiently infiltrated into the channels of SBA-15 nanorods. After calcination and further removal of the silica template, SnO2 nanowire arrays are obtained with a high yield. Then amorphous carbon is deposited onto the interstitial space of these SnO2 nanowire arrays by a facile hydrothermal method followed by subsequent calcination under an inert atmosphere. When the resultant carbon-supported SnO2 nanowire arrays are evaluated as potential anode materials for lithium-ion-batteries (LIBs), they exhibit relatively high capacities with excellent capacity retention.

SnO2 nanosheet hollow spheres with improved lithium storage capabilities

In this work, we employ new chemistry to grow tin oxide nanosheets in the gel matrix of sulfonated polystyrene hollow spheres. After calcination in air, hierarchical hollow spheres assembled from SnO(2) nanosheets can be obtained. In virtue of the porous shell structure and internal voids, these SnO(2) hierarchical nanosheet hollow spheres exhibit improved lithium storage capability.

Unusual rutile TiO2 nanosheets with exposed (001) facets

In this work, we report an interesting synthesis of unusual rutileTiO2 nanosheets with exposed high-energy (001) facets, which form hierarchical microspheres that closely resemble the natural “desert rose”. These high-energy (001) surfaces are stabilized by amorphous molybdenum trioxide (MoO3), which is homogeneously dispersed on the TiO2 nanosheets. The as-prepared unique TiO2–MoO3 hybrid structure exhibits improved lithium storage capabilities.

Carbon/ZnO Nanorod Array Electrode with Significantly Improved Lithium Storage Capability

Carbon/ZnO Nanorod Array Electrode with Significantly Improved Lithium Storage Capability

Carbon/ZnO Nanorod Array Electrode with Significantly Improved Lithium Storage Capability.

Carbon/ZnO nanorod arrays on nickel substrate have been fabricated over a large area by the simple carbonization of preadsorbed glucose on ZnO arrays at 500 °C in argon gas. The uniform coating of average 6 nm carbon shell on ZnO nanorod surface is confirmed. The novel array architecture possesses both the electroactivity of carbon and the electrochemical advantages of array structure on conductive substrate. When used as anode for Li ion batteries, it displays significantly improved performance in terms of cycling stability and rate capability. The observed lithium storage ability ranges among the best reported to date for ZnO-based anode. We believe that the novel carbon-coating route is general and can be extendable to other metal oxide nanoarray electrodes.