Lithium-ion Storage Properties Research Articles

Tailoring yolk–shell FeP@carbon nanoboxes with engineered void space for pseudocapacitance-boosted lithium storage

A unique yolk–shell FeP@C nanobox is synthesized by an etching-in-box combined with a phosphidation-in-box approach, manifesting remarkable pseudocapacitance-boosted lithium ion storage properties.

MOF-derived Zn–Mn mixed oxides@carbon hollow disks with robust hierarchical structure for high-performance lithium-ion batteries

A new hollow yet hierarchical MOF structure is developed to construct robust Zn–Mn oxides@carbon hybrids with excellent lithium-ion storage properties.

Two-Dimensional Holey Nanoarchitectures Created by Confined Self-Assembly of Nanoparticles via Block Copolymers: From Synthesis to Energy Storage Property.

Advances in liquid-phase exfoliation and surfactant-directed anisotropic growth of two-dimensional (2D) nanosheets have enabled their rapid development. However, it remains challenging to develop assembly strategies that lead to the construction of 2D nanomaterials with well-defined geometry and functional nanoarchitectures that are tailored to specific applications. Here we report a facile self-assembly method leading to the controlled synthesis of 2D transition metal oxide (TMO) nanosheets containing a high density of holes. We utilize graphene oxide sheets as a sacrificial template and Pluronic copolymers as surfactants. By using ZnFe2O4 (ZFO) nanoparticles as a model material, we demonstrate that by tuning the molecular weight of the Pluronic copolymers we can incorporate the ZFO particles and tune the size of the holes in the sheets. The resulting 2D ZFO nanosheets offer synergistic characteristics including increased electrochemically active surface areas, shortened ion diffusion paths, and strong inherent mechanical properties, leading to enhanced lithium-ion storage properties. Postcycling characterization confirms that the samples maintain structural integrity after electrochemical cycling. Our findings demonstrate that this template-assisted self-assembly method is a useful bottom-up route for controlled synthesis of 2D nanoarchitectures, and these holey 2D nanoarchitectures are promising for improving the electrochemical performance of next-generation lithium-ion batteries.

Nanosized FexNi2-xP embedded phosphorus-doped carbon nanorods with superior lithium storage performance

Novel hybrid transition metal phosphides with elaborate designed architectures are long pursued to improve their lithium-ion storage properties. Here, nanocomposite of FexNi2-xP particles and P-doped carbon (P-C) substrate has been successfully synthesized through a one-step low-temperature phosphidation of Fe2Ni MIL-88 nanorods. In this nanocomposite, the nano-sized FexNi2-xP particles are embedded into the P-doped carbon nanorods substrate, integrating the high capacity of FexNi2-xP and the excellent conductivity of P-doped carbon together. When used as anode material for lithium-ion batteries, the nanocomposite exhibits a high reversible capacity of 775mAhg−1 after 400 cycles at a current density of 100mAg−1. Even at a high current density of 2000mAg−1, a discharge capacity of 360mAhg−1 could still be maintained. This excellent electrochemical performance may be attributed to the nano-sized building blocks of FexNi2-xP particles and the improved conductivity contributed by P-doped carbon substrate as well as the strong interaction between FexNi2-xP and carbon. Furthermore, this strategy of synthesizing the FexNi2-xP/P-C nanorods with metal-organic frameworks as a starting point can be extended to design other bimetallic transition metal phosphides with superior lithium storage properties.

High Conductive Two-Dimensional Covalent Organic Frameworks for Anodes of Lithium-Ion Batteries

Two-dimensional covalent organic framework (COF) nanosheets based on 5,10,15,20-tetra(4-thiophenephenyl)- porhyrin (TThPP) featuring high conductivity were synthesized using an in-situ chemical oxidative polymerization method. Here, we show for the first time a 2D COF used as the anode for lithium-ion batteries. When used as anode material for lithium ion batteries, the TThPP anode displayed good lithium-ion storage properties with high specific capacities, excellent rate performances, and long cycle lives compared with that of graphitic (372 mAh g−1) and other organic anodes. The reversible capacity is up to 666 mAh g−1. The TThPP also exhibited high energy and power densities of 48.44 Wh kg−1 and 700.36 W kg−1 respectively when used as the anode of a hybrid capacitor. The unique nanosheet morphology of the TThPP anode films provide efficient adsorption sites for Li atoms, short-ended paths for the fast lithium-ion diffusion, and open nanopores for holding electrolyte that contribute to the excellent electrochemical performance.

AlF3-modified LiCoPO4 for an advanced cathode towards high energy lithium-ion battery

Surface-interface reaction between the electrode and electrolyte plays a key role in lithium-ion storage properties, especially for high voltage cathode such as LiCoPO4 and Ni-riched cathode. Generally, surface modification is an effective method to improve the electrochemical performance of electrode materials. Herein, in order to revise the LiCoPO4 cathode with desirable properties, uniform AlF3-modified LiCoPO4 (LiCoPO4@AlF3) cathode materials in nano-sized distribution are synthesized. XRD result indicates that there is no structural transformation observed after AlF3 coating. TEM characterization and XPS analysis reveal that the surface of LiCoPO4 particle is coated by a nano-sized uniform AlF3 layer. Further, the electrochemical results indicate that AlF3 layer significantly improves the cycling and rate performances of LiCoPO4 cathode within the voltage range of 3.0–5.0V. After a series of optimization, 4mol% AlF3-coated LiCoPO4 material exhibits the best properties including an initial discharge capacity of 159mAhg−1 at 0.1C with 91% capacity retention after 50 cycles, especially a discharge capacity of 90mAhg−1 can be obtained at 1C rate. CV curves indicate that the polarization of cathode is reduced by AlF3 layer and EIS curves reveal that AlF3 layer relieves the increase of resistance to facilitate Li-ion transfer at the interface between electrode and electrolyte during the cycling process. The enhanced electrochemical performances are attributed to that the AlF3 layer can stabilize the interface between the cathode and electrolyte, form steady SEI film and suppress the electrolyte continuous decomposition at 5V high voltages. This feasible strategy and novel characteristics of LiCoPO4@AlF3 could promise the prospective applications in the stat-art of special lithium-ion battery with high energy and/or power density.

Yolk@Shell or Concave Cubic NiO-Co3O4@C Nanocomposites Derived from Metal-Organic Frameworks for Advanced Lithium-Ion Battery Anodes.

Novel hybrid metal oxides with advanced architectures are extensively pursued to achieve synergetic properties with respect to improved lithium-ion storage properties. Here, rationally designed yolk@shell or concave NiO-Co3O4@C (YNCC or CNCC) nanocubes have been fabricated by the simple and versatile thermolysis-induced transformation of metal-organic frameworks (MOFs), aimed at simultaneously addressing the capacity fade and conductivity deficiency of metal oxides. The as-prepared nanocomposites with plentiful hierarchical pores integrate the distinct functionalities of the ternary components: NiO and Co3O4 as the major active materials can guarantee high capacity, while carbon can improve the conductivity and accommodate volume changes. Benefitting from the intrinsic material and architecture features, the YNCC and CNCC nanocomposites deliver excellent electrochemical performances with high reversible specific capacity, superior cycling stability (803 and 870 mAh g-1 at 100 mA g-1 after 100 cycles), and good rate capability (339 and 398 mAh g-1 at 2 A g-1) as anode materials for lithium-ion batteries.

Cobalt fibers anchored with tin disulfide nanosheets as high-performance anode materials for lithium ion batteries

Well-designed hierarchical nanostructured composites consisting of one dimensional cobalt fibers and thin tin disulfide nanosheets were successfully synthesized for the first time through a hydrothermal method. The SnS2 nanosheets were uniformly grown onto the Co fibers and were almost perpendicular to the Co fibers. The composites as one kind anode materials exhibited more remarkable lithium ion storage properties than SnS2 nanosheets. The composites exhibited a capacity of 500.5mAh/g after 100 cycles even at 1000mA/g. The improved electrochemical performance could be assigned to the Co fiber substrate support, which could provide short lithium ion and electron pathways, alleviate large volume expansion, contribute to the capacity, and offer mechanical stability for the anode electrode. This special designing perhaps could lay a foundation for the preparation of high performance lithium ion battery anode materials.

Fabrication of hierarchically porous TiO2 nanofibers by microemulsion electrospinning and their application as anode material for lithium-ion batteries.

Titanium dioxide (TiO2) nanofibers have been widely applied in various fields including photocatalysis, energy storage and solar cells due to the advantages of low cost, high abundance and nontoxicity. However, the low conductivity of ions and bulk electrons hinder its rapid development in lithium-ion batteries (LIB). In order to improve the electrochemical performances of TiO2 nanomaterials as anode for LIB, hierarchically porous TiO2 nanofibers with different tetrabutyl titanate (TBT)/paraffin oil ratios were prepared as anode for LIB via a versatile single-nozzle microemulsion electrospinning (ME-ES) method followed by calcining. The experimental results indicated that TiO2 nanofibers with the higher TBT/paraffin oil ratio demonstrated more axially aligned channels and a larger specific surface area. Furthermore, they presented superior lithium-ion storage properties in terms of specific capacity, rate capability and cycling performance compared with solid TiO2 nanofibers for LIB. The initial discharge and charge capacity of porous TiO2 nanofibers with a TBT/paraffin oil ratio of 2.25 reached up to 634.72 and 390.42 mAh·g−1, thus resulting in a coulombic efficiency of 61.51%; and the discharge capacity maintained 264.56 mAh·g−1 after 100 cycles, which was much higher than that of solid TiO2 nanofibers. TiO2 nanofibers with TBT/paraffin oil ratio of 2.25 still obtained a high reversible capacity of 204.53 mAh·g−1 when current density returned back to 40 mA·g−1 after 60 cycles at increasing stepwise current density from 40 mA·g−1 to 800 mA·g−1. Herein, hierarchically porous TiO2 nanofibers have the potential to be applied as anode for lithium-ion batteries in practical applications.

Chestnut-like SnO2/C nanocomposites with enhanced lithium ion storage properties

Chestnut-like SnO2 and SnO2/C nanocomposites with hierarchical structures are synthesized by hydrothermally oxidizing Sn nanoparticles in glucose solution. Structural characterizations using SEM and TEM reveal that the SnO2 nanoparticles are composed of numerous, randomly arranged SnO2 nanosheets with hollow cores. Owing to the short electron and ion diffusion distances and transformation strain accommodation mechanism of this structure the new SnO2/C nanocomposites exhibit enhanced lithium ion storage properties with a capacity of ~930mAhg−1 and capacity retention of about 96% after 100 cycles at 0.1C. An in situ TEM study of the electrochemically driven lithiation/delithiation of SnO2/C nanocomposites reveals that their enhanced cycling stability is mainly facilitated by the limited volume expansion and excellent mechanical robustness of the hollow chestnuts.

Porous carbon-coated ZnO nanoparticles derived from low carbon content formic acid-based Zn(II) metal-organic frameworks towards long cycle lithium-ion anode material

Single-C formic acid-based metal-organic frameworks (MOFs) are used to construct novel ZnO@porous carbon matrix nanocomposites by controlled pyrolysis. In the constructed nanocomposites, the porous carbon matrices act as a confined support to prevent agglomeration of the ZnO nanoparticles and create a rapid electron conductive network. Meanwhile, the well-defined, continuous porous structured MOFs provide a large specific surface area, which increases the contact of electrolyte-electrode and improves the penetration of electrolyte. Especially, the reasonable choice of formic acid-based MOFs construct the low carbon content composite, which contribute to the high energy density and long cycle life. The constructed nanocomposites show stable, ultrahigh rate lithium ion storage properties of 650mAhg−1 at charge/discharge rate of 1C even after 200 cycles.

NiO hollow microspheres interconnected by carbon nanotubes as an anode for lithium ion batteries

In this work, NiO hollow microspheres interconnected by multi-walled carbon nanotubes (MWCNTs) were prepared, characterized, and evaluated in terms of lithium ion storage properties. Characterization results showed that the NiO hollow microspheres were formed by self assembly of NiO nanoparticles promoted by MWCNTs, which connected the NiO microspheres to form a long-range network. Electrochemical measurement results showed a charge capacity as high as 597.2mAhg−1 when cycling at the rate 2C and maintained 85.3% capacity of 0.1C. After cycling for 100 times at 1C, it maintained a capacity of 692.3mAhg−1 with retention 89.3% of the initial capacity. The observed excellent electrochemical performance is attributed to the presence of MWCNTs interconnecting the NiO microspheres of the composite material, of which electronic conductivity was improved, and the mesoporous hollow structure effectively alleviated the volume changes to maintain the structural stability during cycling.

Fabrication of cubic spinel MnCo2O4 nanoparticles embedded in graphene sheets with their improved lithium-ion and sodium-ion storage properties

Abstract Cubic Spinel MnCo2O4/graphene sheets (MCO/GS) nanocomposites are synthesized by a facile hydrothermal method with a subsequent annealing process. Nano-sized MnCo2O4 particles are evenly embedded in paper-like graphene sheets, possessing a unique nanoparticles-on-sheets hybrid nanostructure, with particle size around 20–50 nm. Owing to the special nanoparticles-on-sheets structures, MCO/GS nanocomposites have an outstanding electrochemical performance for rechargeable energy storage devices. As an anode material for lithium-ion batteries, MCO/GS electrodes exhibit high reversible discharge capacities (1350.4 mAh g−1 at the initial rate of 100 mA g−1), excellent rate capability (462.1 mAh g−1 at a current rate of 4000 mA g−1) and outstanding cycling performance (584.3 mAh g−1 at 2000 mA g−1 after 250 cycles). Meanwhile, as an anode material for sodium-ion batteries, MCO/GS electrodes also exhibit comparably promising electrochemical characteristics. Greatly improved electrochemical properties can be assigned to the special advantageous nanostructures. Besides, the existence of graphene sheets is beneficial to the transportation of ions/electrons during battery operation. The outstanding electrochemical performance demonstrates that the lithium/sodium storage capability of MCO/GS nanocomposites is highly promising for high-capacity batteries.

Formation of Sn–M (M=Fe, Al, Ni) alloy nanoparticles by DC arc-discharge and their electrochemical properties as anodes for Li-ion batteries

A direct current arc-discharge method was applied to prepare the Sn–M (M=Fe, Al, Ni) bi-alloy nanoparticles. Thermodynamic is introduced to analyze the energy circumstances for the formation of the nanoparticles during the physical condensation process. The electrochemical properties of as-prepared Sn–M alloy nanoparticles are systematically investigated as anodes of Li-ion batteries. Among them, Sn–Fe nanoparticles electrode exhibits high Coulomb efficiency (about 71.2%) in the initial charge/discharge (257.9mAhg−1/366.6mAhg−1) and optimal cycle stability (a specific reversible capacity of 240mAhg−1 maintained after 20 cycles) compared with others. Large differences in the electrochemical behaviors indicate that the chemical composition and microstructure of the nanoparticles determine the lithium-ion storage properties and the long-term cyclic stability during the charge/discharge process.

Effects of high surface energy on lithium-ion intercalation properties of Ni-doped Li3VO4

Nickel was doped into Li3VO4 (Ni-LVO) successfully via a facile room temperature reaction, and the resulting Ni-LVO nanocrystallites showed excellent lithium-ion storage properties with a capacity of 650 mAh g−1 at 50 mAh g−1 and excellent capacity stability as an anode in lithium-ion batteries, maintaining nearly 100% of the initial reversible capacity after 800 cycles at 1 A g−1. The superior electrochemical properties arose largely from the nickel doping in the Ni-LVO. The surface energy of the electrode material was analyzed by an inverse gas chromatography method, and the Ni-LVO surface energy, 43.91 mJ m−2, was much higher than the 30.74 mJ m−2 of Li3VO4. X-ray photoelectron spectra results demonstrated that nickel doping promoted the formation of tetravalent vanadium ions, V4+, as well as a more amorphous surface of Li3VO4, thus probably resulting in more nucleation sites for the phase transformation and reduced activation energy of the redox reactions and phase transition during the lithium-ion intercalation/extraction processes. Using nickel-doped nanocrystals boosts the stability and charge storage of rechargeable lithium-ion batteries, find scientists in China. Lithium and vanadium containing oxides, such as lithium vanadate (Li3VO4), could replace graphite anodes used in commercial lithium-ion batteries because they possess more stable crystal structure and offer greater energy storage. Guozhong Cao and colleagues at the National Center for Nanoscience and Technology have found how to make the switch to Li3VO4 anodes feasible by improving this materials' poor electrical conductivity. The researchers used a simple mixing procedure to introduce nickel atoms into the Li3VO4 framework and found that the resulting nanocrystals significantly enhanced battery performance. Characterization experiments revealed that these improvements arose from nickel's electrochemical and surface-disrupting effects: amorphous surface regions induced by the dopants likely resulted in additional nucleation sites for lithium-ion extraction and intercalation processes. Nickel doped Li3VO4 nanocrystallites with high surface energy showed excellent lithium ion storage property with a capacity of 650 mAh g−1 at 50 mAh g−1 and excellent capacity stability as anode in lithium ion batteries. The nickel doping promoted the formation of V4+ and more amorphous in the surface of Li3VO4, probably resulting in higher surface energy, more nucleation sites for the phase transformation and reducing the activation energy of the redox reactions and phase transition during the Li+ intercalation/extraction processes.

TiO2 hierarchical hollow microspheres with different size for application as anodes in high-performance lithium storage

Nowadays, the safety issue has greatly hindered the development of large capacity lithium-ion batteries (LIBs), especially in electric vehicles applications. TiO2 is a kind of potential anode candidate for improving the safety of LIBs. However, it still needs to understand how to improve the performance of TiO2 anode in the practical applications. Herein, we design a contrast experiment by using three sizes of TiO2 hierarchical hollow microspheres (TiO2-HSs). The research results indicated that the cycling performance of TiO2-HSs anode can be affected by the size of microspheres, and the nanoparticles size of microspheres and crystallinity of TiO2 can affect their initial discharge capacity and lithium ion diffusion. And, the influence of microspheres size is more significant. This may provide a new strategy for improving the lithium-ion storage property of TiO2 anode material in the practical applications.

Morphology- and facet-controlled synthesis of CuO micro/nanomaterials and analysis of their lithium ion storage properties

Hierarchical CuO architectures and monodisperse CuO nanoplates are synthesized via a hydrothermal method with the assistance of ionic liquid 1-butyl-3-methylimidazolium chloride ([Bmim]Cl). The products are characterized by XRD, SEM, TEM, HRTEM, BET, and XPS, and the results indicate that the CuO architectures are composed of nanosheets with exposed (001) facets and the CuO nanoplates are single crystals enclosed by (200) facets. More specially, it is found that [Bmim]Cl serves as an effective template for the synthesis of CuO nanoplates by adsorbing on the (200) planes of monoclinic CuO. When evaluated as anode materials for lithium-ion batteries, CuO architectures possess higher discharge capacity, better cycling stability, and better rate capability than CuO nanoplates. The initial discharge capacity of CuO architectures is 1096 mAh g−1 at a rate of 0.5 C, whereas CuO nanoplates exhibit a lower capacity of 878.4 mAh g−1. Moreover, after 50 cycles, CuO architectures and CuO nanoplates can deliver discharge capacities of 465.6 and 281.6 mAh g−1, respectively.

Electrospinning Synthesis of Ni°, Fe° Codoped Ultrafine-ZnFe2O4/C Nanofibers and Their Properties for Lithium Ion Storage

This work discusses codoping moderate metal nanoparticles (Ni, Fe) on the ferrite/C composite nanofibers to improve the electronic conductivity. The ultrafine Ni0.5Zn0.5Fe2O4/Ni/C, ZnFe2O4/Ni/Fe/C, and ZnO/Ni/Fe/C nanofibers are synthesized by electrospinning and subsequent annealing at 450, 550 and 650°C, respectively. Their growth mechanism, morphologies and lithium ion storage properties are investigated in detail. ZnFe2O4/Ni/Fe/C exhibits the best electrochemical performance. The composite shows an initial discharge capacity of 1316mAhg−1 and manages to achieve a capacity of 793mAhg−1 after 200 cycles at 100mAg−1. A high capability of 450mA h g−1 is still obtained when the current density increases to 1Ag−1. We also compare the lithium ion storage properties of pure ZnFe2O4, ZnFe2O4/C and ZnFe2O4/Ni/Fe/C to demonstrate the positive effect of codoping ferrites by Ni and Fe nanoparticles with amorphous carbon mixed.

Stripe- or square-patterned arrays of tin dioxide nanowires for use in lithium-ion battery electrodes

This paper reports a novel electrode design for use in electrochemical lithium-ion storage. 3-dimensional patterns of tin dioxide nanowires that are grown directly over current collectors are suggested as electrode frameworks, representing the synergetic combination of nanometer-sized 1-dimensional electrode materials and micrometer-scaled hollow channels formed between the patterned nanowire arrays. The lithium-ion storage properties are investigated by changing the pattern geometries of these nanowire arrays in the shape of stripes and squares. The proposed electrode platforms show the enhanced electrochemical storage performances, which might be attributed to the effective diffusion of liquid phase electrolyte through the hollow channels between these patterned nanowire arrays. More interestingly, with increasing the hollow channels in these proposed systems, the high-rate performance and cycling stability are improved even further due to the structural effect of these electrode frameworks.

Strategies to succeed in improving the lithium-ion storage properties of silicon nanomaterials

In this review, we summarize several strategies developed recently for enhancing the lithium-ion storage properties of Si materials.