Performance Anodes For Lithium-ion Batteries Research Articles

A bottom-up synthesis of α-Fe2O3 nanoaggregates and their composites with graphene as high performance anodes in lithium-ion batteries

The composites of graphene and α-Fe2O3 nanoaggregates as the anode of lithium ion battery exhibit stable cyclability and a high specific capacity of 1787.27 mA h g−1 at 0.1 A g−1.

Synthesis of Sn–Co@PMMA nanowire arrays by electrodeposition and in situ polymerization as a high performance lithium-ion battery anode

Transition metals have attracted much attention due to their high energy density in lithium-ion batteries (LIBs).

Direct amination of Si nanoparticles for the preparation of Si@ultrathin SiOx@graphene nanosheets as high performance lithium-ion battery anodes

Graphene nanosheet encapsulated Si nanoparticles with an ultrathin silica shell have been fabricated by an environmentally friendly and effective amination method.

Experimental and theoretical investigations of nitro-group doped porous carbon as a high performance lithium-ion battery anode

The lithium adsorption abilities of various functional groups (NH2, NO2, SO3H, Cl, Br, I) are studied by first-principles quantum chemical calculations which are doped at the edge of graphene sheets. Among all the groups, the nitro-group shows the best properties.

MnO/C nanocomposite prepared by one-pot hydrothermal reaction for high performance lithium-ion battery anodes

Among various candidates to replace the low capacity graphitic carbon anode in current lithium ion batteries (LIBs), manganese oxides possess the advantages of high lithium storage capacity, low cost, high intrinsic density, environmental friendliness and low lithium storage voltage, i.e., 0.5 V Li+/Li. Manganese oxides, however, have to be incorporated with conducting and porous matrix due to poor electrical conductivity and large volume expansions associated with conversion reaction upon cycling. In this study, a facile one-pot route was attempted for the synthesis of MnO/C nanocomposite for which Mn3O4 nanoparticles were grown in aqueous medium followed by carbon gel formation in a one-pot reactor. Thus obtained Mn3O4/C carbon gel was transformed into MnO/C nanocomposite by thermal annealing in an Ar flow. The MnO nanoparticles (60wt%) of 20–50 nm in diameter were well dispersed throughout the MnO/C composite. The MnO/C composite delivered reversible capacity of 541mAh g−1 with an excellent cycling stability over 100 cycles, while parent Mn3O4 lost most of its capacity in 10 cycles. The MnO/C composite also exhibited much higher rate capability than a commercial graphite anode. Hence, the MnO/C composite based on low cost materials and facile synthetic process could be an attractive candidate for large-scale energy storage applications.

One-step electrochemical growth of a three-dimensional Sn-Ni@PEO nanotube array as a high performance lithium-ion battery anode.

Various well-designed nanostructures have been proposed to optimize the electrode systems of lithium-ion batteries for problems like Li(+) diffusion, electron transport, and large volume changes so as to fulfill effective capacity utilization and increase electrode stability. Here, a novel three-dimensional (3D) hybrid Sn-Ni@PEO nanotube array is synthesized as a high performance anode for a lithium-ion battery through a simple one-step electrodeposition for the first time. Superior to the traditional stepwise synthesis processes of heterostructured nanomaterials, this one-step method is more suitable for practical applications. The electrode morphology is well preserved after repeated Li(+) insertion and extraction, indicating that the positive synergistic effect of the alloy nanotube array and 3D ultrathin PEO coating could authentically optimize the current volume-expansion electrode system. The electrochemistry results further confirm that the superiority of the Sn-Ni@PEO nanotube array electrode could largely boost durable high reversible capacities and superior rate performances compared to a Sn-Ni nanowire array. This proposed ternary hybrid structure is proven to be an ideal candidate for the development of high performance anodes for lithium-ion batteries.

Facile synthesis of MnO multi-core@nitrogen-doped carbon shell nanoparticles for high performance lithium-ion battery anodes

Novel MnO multi-core@nitrogen-doped carbon shell nanoparticles (MCNCmSPs) were developed through a facile polydopamine adhesive-assisted compositing procedure. Owing to their advanced multi-core@shell nanostructure, the as-prepared MCNCmSPs exhibited remarkable electrochemical performance as lithium-ion battery anode.

Low temperature synthesis of carbon encapsulated Fe7S8 nanocrystals as high performance anode for lithium-ion batteries

A novel method is developed for low temperature synthesis of carbon encapsulated spherical Fe7S8 nanocrystals with core–shell structure (Fe7S8@C) by the reaction of ferrocene with ammonium persulphate. The phase structure, morphology, specific surface area and composition of the nanocomposite are systematically characterized. It is found that the Fe7S8 nanocrystals with a weight percent of 33.5% have a median size of 25.2 nm. The Fe7S8@C electrodes retain a reversible capacity of 815 and 539 mAh g−1 after 50 cycles at a current density of 200 and 2284 mA g−1, respectively. The high capacity, good cycling behavior and rate capability of Fe7S8@C electrodes are attributed to the good protection and electrical conductivity of carbon shell.

3D hollow framework of GeOx with ultrathin shell for improved anode performance in lithium-ion batteries

In this paper, 3D hollow framework of GeOx is synthesized using a bubble-template hydrothermal procedure. The as-obtained hollow structure exhibits excellent cycling performance and rate capability in comparison with GeOx nanoparticles when used as an anode material in lithium ion batteries. The GeOx 3D hollow framework shows a high capacity of up to 1480 mAh·g−1 and 1109 mAh·g−1 at 80 mA·g−1 and 1600 mA·g−1 current density, respectively. The excellent lithium storage performance can be attributed to the unique 3D hollow framework. The framework not only acts as the buffer layer to alleviate the strain during lithiation, but also facilitates the electron transfer during the charge/discharge processes.

Facile and surfactant-free synthesis of SnO2-graphene hybrids as high performance anode for lithium-ion batteries

A facile microwave-assisted ethylene glycol method is developed to synthesize the SnO2 nanoparticles dispersed on or encapsulated in reduced graphene oxide (SnO2-rGO) hybrids. The morphology, structure, and composition of SnO2-rGO are investigated by scanning electron microscopy, transmission electron microscope, thermo-gravimetric analyzer, X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy. The electrochemical performance of SnO2-rGO as anode materials for lithium-ion batteries was tested by cyclic voltammetry, galvanostatic charge–discharge cycling, and rate capability test. It is found that the SnO2 nanoparticles with a uniform distribution have p-type doping effect with rGO nanosheets. The as-prepared SnO2-rGO hybrids exhibit remarkable lithium storage capacity and cycling stability, and the possible mechanism involved is also discussed. Their capacity is 1222 mAhg−1 in the first cycle and maintains at 700 mAhg−1 after 100 cycles. This good performance can be mainly attributed to the unique nanostructure, good structure stability, more space for volume expansion of SnO2, and mass transfer of Li+ during cycling.

Electrodeposited three-dimensional porous Si–O–C/Ni thick film as high performance anode for lithium-ion batteries

A novel 3D porous Si–O–C/Ni thick film anode is successfully prepared by electrodeposition of porous Ni on Cu substrate and galvanostatical electrodeposition of Si–O–C composite on porous Ni substrate. The 3D porous Si–O–C/Ni thick film is electrochemically activated at a current density of 50 μA cm−2 for the first cycle and 200 μA cm−2 (0.5 C) for the subsequent cycles, it displays superior electrochemical performance with discharge capacity of 706.3 mAh g−1 of Si after 100 cycles. The properties of this thick film is analyzed by field emission scanning electron microscopy (FESEM) and scanning transmission electron microscopy with energy dispersive X-ray analyzer (STEM-EDX). The results show that Si–O–C composite not only covers the surface area of porous Ni but also attaches to the highly porous dendritic walls, along with the porous structure of Ni which provides proper accommodation for the volume change of silicon during the lithiation/delithiation processes, are believed to result in the high capacity and excellent cyclability.

Covalently coupled hybrid of graphitic carbon nitride with reduced graphene oxide as a superior performance lithium-ion battery anode.

An in situ chemical synthetic approach has been designed for the fabrication of a covalently coupled hybrid consisting of graphitic carbon nitride (g-C3N4) with reduced graphene oxide (rGO) with differing g-C3N4/rGO ratio. The epoxy groups of graphene oxide (GO) undergo a nucleophilic substitution reaction with dicyandiamide (C2H4N4) to form the C2H4N4-GO composite via a covalent C-N bond, and then both the in situ polymerization of C2H4N4 and the thermal reduction of GO can be achieved at higher temperatures, forming the covalently coupled g-C3N4-rGO. FT-IR, CP-MAS NMR and XPS analyses, clearly revealed a covalent interaction between the g-C3N4 and rGO sheets. The g-C3N4-rGO exhibits an unprecedented high, stable and reversible capacity of 1525 mA h g(-1) at a current density of 100 mA g(-1) after 50 cycles. Even at a large current density of 1000 mA g(-1), a reversible capacity of 943 mA h g(-1) can still be retained. The superior electrochemical performance of g-C3N4-rGO is attributed to the specific characteristics of the unique nanostructure of g-C3N4-rGO and the concerted effects of g-C3N4 and rGO, including covalent interactions between the two moieties, the good conductivity and high special surface area of the nanocomposite, as well as the template effect of the planar amino group of g-C3N4 for the dispersed decoration of Li(+) ions.

Scalable Synthesis of Self-Assembled Metal-Oxide/Carbon Nanosheets for High Performance Lithium-Ion Battery Anodes

The assembly of uniform nanoparticles has attracted much attention since well-aligned ensembles of nanoparticles often show interesting properties that are different from those displayed by individual nanoparticles and bulk materials. Various methods were developed for periodically ordered arrays of the synthesized nanoparticles including “evaporation-driven” methods and “destabilization-driven” approaches. Herein, a simple and scalable method for the synthesis of self-assembled metal-oxide/carbon nanosheets is reported.The carbon nanosheets embedded with self-assembled uniform metal-oxide nanoparticles were synthesized simultaneously through a solventless heating procedure using a single precursor for both metal-oxide and carbon. Two-dimensional nanostructured materials were got by using salt powder as a sacrificial template. The size and shape of the metal oxide nanoparticles embedded in carbon could be controlled by varying the experimental conditions. The nanostructured materials were characterized by using scanning electron microscopy, transmission electron microscopy and X-ray diffraction.As a demonstration of the metal-oxide/carbon nanosheets as lithium-ion battery anode materials, electrochemical tests were carried out in a coin type cell assembly. Galvanostatic discharge/charge voltage profiles were got at a current density of 100 mA g− 1. The rate capability of the electrodes is also studied. At a high rate of 5000 mA g− 1, 81.5% of original capacity was retained for the manganese-ferrite/carbon nanosheets, whereas 68.7%, 56.8%, and 41.6% were retained for 16 nm iron-oxide/carbon nanosheets, 30 nm iron-oxide/carbon nanosheets, and 3- dimensional aggregated nanocomposites, respectively.Comparing the iron-oxide/carbon nanosheets and three-dimensional aggregated nanocomposites, well-ordered iron-oxide/carbon nanosheets have several advantages in terms of resistance to mechanical deformation. The self-assembled nanostructure seems to induce the regularly spaced carbon walls between the nanoparticles, providing tensile strength in the vertical direction of the carbon sheet. In addition, iron-oxide/carbon nanosheets have enough room to expand in this direction than three-dimensional aggregated nanocomposites, which can provide a buffer for the volume change. As a result, these structural factors can contribute to improved cycle performance of the nanosheets. TEM measurements were made on the nanosheet electrodes after 10th charge/discharge cycling at a rate of 100 mA g− 1 to investigate the mechanical deformation during the electrochemical cycling. The iron-oxide nanosheet structure was sustained without peeling off. The encapsulating carbon shells seem to help to maintain the structure of iron-oxide/carbon nanosheet electrodes. The rate capacity of the electrodes is affected by the diffusion of lithium ions from the electrolyte to the active material.The as-prepared hybrid nanosheets showed excellent cycling stability and rate performance as anode materials for lithium-ion batteries derived from two-dimensional nanostructural characteristics. The superior electrochemical performance of the nanosheets is due to their short diffusion path and large accessible surface for the effective insertion of lithium ions. Moreover, the size of the metal oxide nanoparticles strongly affected the electrochemical performance at high charging/discharging rates. In addition, the large Coulombic capacity at high discharge rates seems to have resulted from the uniform-sized ferrite nanoparticles.The synthetic procedure is very simple, inexpensive, and scalable for mass production, and the highly ordered two-dimensional hybrid nanosheets have great potentials for various future applications.

Controllable synthesis Co3O4 nanorods and nanobelts and their excellent lithium storage performance

Co3O4 nanorods and nanobelts can be synthesized controllably by a template-free hydrothermal method. Enhanced lithium-ion battery performances are obtained from Co3O4 nanorods and nanobelts. After 50 cycles, the reversible capacity is up to 1124 and 1260 mAh g−1 at C/20 rate (20 h per half cycle), respectively, and the cyclability are excellent. Lithium-ion battery performance of nanobelts is much higher than that of nanorods. Such a behavior is attributed to more efficient Li insertion, less volume change and no agglomeration of nanobelts. The present results open a way for fabrication of porous 1D nanostructures and imply that porous 1D nanostructures are good candidates for high performance lithium-ion battery anodes.

Porous Si spheres encapsulated in carbon shells with enhanced anodic performance in lithium-ion batteries

A novel type of porous Si–C micro/nano-hybrids, i.e., porous Si spheres encapsulated in carbon shells (porous Si@C spheres), has been constructed through the pyrolysis of polyvinylidene fluoride (PVDF) and subsequent magnesiothermic reduction methodology by using SiO2 spheres as precursors. The as-synthesized porous Si@C spheres have been applied as anode materials for lithium-ion batteries (LIBs), and exhibit enhanced anodic performance in term of cycling stability compared with bare Si spheres. For example, the porous Si@C spheres are able to exhibit a high reversible capacity of 900.0mAhg−1 after 20 cycles at a current density of 0.05C (1C=4200mAg−1), which is much higher than that of bare Si spheres (430.7mAhg−1).

Nanoimprinted Carbon Structures As High Performance Lithium Ion Battery Anodes

We demonstrated the synthesis of carbon thin film with ordered nanostructure via nanoimprint lithography starting from thermal plastic polymer polyvinylpyrrolidone (PVP). After the pattern is completely transferred onto PVP thin film during the nanoimprinting process, a three-step thermal treatment is performed to convert the polymer into patterned carbon thin film. Feature size of the pattern ranges between 250 nm up to 2 um with various shapes including 1D line, 2D hole and pillar. Characterized with Raman spectroscopy, the carbon thin film shows a high degree of disorder with a small in-plane graphitic crystallite size of about 1.346 nm calculated using the peak intensity of D band and G band of sp2carbon. Those patterned carbon thin film exhibits good electrical conductivity. When used as anode of lithium ion battery, it shows an enhanced cyclic performance compared to those unpatterned carbon thin films and also graphite. Further study with Electrochemical Strain Microscope (ESM) helps to understand the enhanced Li ion storage capacity locally on the nanoscale.Figure 1. (A) Atomic force microscopy topography scan of imprinted carbon thin film, (B) cyclic charge/discharge performance of imprinted and unpatterned carbon.

Porous Co3O4 nanorods as anode for lithium-ion battery with excellent electrochemical performance

In this manuscript, porous Co3O4 nanorods are prepared through a two-step approach which is composed of hydrothermal process and heating treatment as high performance anode for lithium-ion battery. Benefiting from the porous structure and 1-dimensional features, the product becomes robust and exhibits high reversible capability, good cycling performance, and excellent rate performance.

A Facile Synthetic Approach to Reduced Graphene Oxide–Fe3O4 Composite as High Performance Anode for Lithium-ion Batteries

Reduced graphene oxide–Fe3O4 (rGO–Fe3O4) composite has been prepared via a facile and effective hydrothermal method by synthesizing Fe3O4 nanospheres on the planes of reduced graphene oxide (rGO). Characterizations suggest the successful attachment of Fe3O4 nanospheres to rGO sheets. The rGO–Fe3O4 composite (66.7 wt% of Fe3O4 in the composite) exhibits a stable capacity of 668 mAh g−1 without noticeable fading for up to 200 cycles in the voltage range of 0.001–3.0 V, and the superior performance of rGO–Fe3O4 is clearly established by comparison of the results with those from bare Fe3O4 nanospheres (capacity declined to 117 mAh g−1 only at the 200th cycle). The excellent electrochemical performance of rGO–Fe3O4 composite can be attributed to the fact that the uniform dispersion of the Fe3O4 nanospheres growing on the rGO sheets avoids aggregation during Li uptake-release cycling, which is desired for cycle stability. Meanwhile, the rGO sheets afford not only elastic buffer to alleviate the volume variations of Fe3O4 nanospheres, but also good ionic and electronic transport medium in the electrode.

Hierarchically porous TiO2microspheres as a high performance anode for lithium-ion batteries

Hierarchically porous rutile TiO2 microspheres composed of nanorods were fabricated by using a facile synthetic route. These materials were characterized by X-ray diffraction (XRD), N2 adsorption–desorption, and scanning and transmission electron microscopy (SEM and TEM). Based on a series of experimental results, a self-assembly process for the formation of the hierarchical microspheres was also proposed. Furthermore, the hierarchically porous rutile TiO2 microspheres were used as the negative electrode material in lithium-ion batteries (LIBs) and demonstrated a large reversible charge–discharge capacity of 160.4 mA h g−1 after 100 cycles at 1 C, which was much greater than commercial rutile TiO2 under the same conditions, indicating that these materials had excellent cycling stability and high rate performance.

Hollow/porous nanostructures derived from nanoscale metal–organic frameworks towards high performance anodes for lithium-ion batteries

Lithium-ion batteries (LIBs), owing to their high energy density, light weight, and long cycle life, have shown considerable promise for storage devices. The successful utilization of LIBs depends strongly on the preparation of nanomaterials with outstanding lithium storage properties. Recent progress has demonstrated that hollow/porous nanostructured oxides are very attractive candidates for LIBs anodes due to their high storage capacities. Here, we aim to provide an overview of nanoscale metal-organic frameworks (NMOFs)-templated synthesis of hollow/porous nanostructured oxides and their LIBs applications. By choosing some typical NMOFs as examples, we present a comprehensive summary of synthetic procedures for nanostructured oxides, such as binary, ternary and composite oxides. Hollow/porous structures are readily obtained due to volume loss and release of internally generated gas molecules during the calcination of NMOFs in air. Interestingly, the NMOFs-derived hollow/porous structures possess several special features: pores generated from gas molecules release will connect to each other, which are distinct from "dead pores"; pore size often appears to be <10 nm; in terms of surface chemistry, the pore surface is hydrophobic. These structural features are believed to be the most critical factors that determine LIBs' performance. Indeed, it has been shown that these NMOFs-derived hollow/porous oxides exhibit excellent electrochemical performance as anode materials for LIBs, including high storage capacity, good cycle stability, and so on. For example, a high charge capacity of 1465 mA h g(-1) at a rate of 300 mA g(-1) was observed after 50 cycles for NMOFs-derived Co3O4 porous nanocages, which corresponds to 94.09% of the initial capacity (1557 mA h g(-1)), indicating excellent stability. The capacity of NMOFs-derived Co3O4 is higher than that of other Co3O4 nanostructures obtained by a conventional two-step route, including nanosheets (1450 mA h g(-1) at 50 mA g(-1)), nanobelts (1400 mA h g(-1) at 40 mA g(-1)) and nanoflowers (694 mA h g(-1) at 100 mA g(-1)). The capacity is also better than Co3O4 octahedra obtained by a one-step hydrothermal method (946 mA h g(-1) at 100 mA g(-1)). In this review, we will summarize the recent research advances on NMOFs-derived hollow/porous oxides as LIBs anodes. The enhanced lithium storage properties have been discussed in relation to their special structural parameters. Moreover, remarks on the current challenges and perspectives for future NMOFs applications are proposed. Through this systematic review, we aim to stress the importance of NMOFs templates for the fabrication of hollow/porous functional materials that would result in improved physicochemical properties and provide insights to guide future research for LIBs applications.