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Abstract SiO x has emerged as an important alternative to silicon as the high capacity anode host to store lithium due to its smaller volume change upon lithiation. However, conventional synthesis methods generally require harsh reaction conditions, making its production in industrial scale much challenging. Herein, a safe, economical and scalable approach is developed for SiO x using highly abundant natural silica as starting material via a magnesio-mechanochemical reduction process induced by ball-milling. The as-prepared SiO x is intrinsically porous and comprised of mixed nano clusters of SiO 2 and Si. Upon lithiation, SiO 2 nano domains convert into lithium silicates and Li 2 O, which help to absorb Si volume expansion and participate in the formation of a stable solid electrolyte interface. Such synergistic effect leads to exceptional cycling stability up to 2000 cycles with 71.3% capacity retention under 4 A g−1. After blending with graphite, a high areal capacity of 2.64 mAh cm−2 demonstrates stable cycling of 89.7% retention over 200 cycles with an high initial Coulombic efficiency of 82.3%, implying the feasibility for practical applications. Structural and compositional characterizations reveal the involved chemistry and evolution mechanism of the formed solid electrolyte interface upon cycling, providing guidelines of designing future silicon-based materials for future Li-ion batteries. Graphical abstract Image 1 Highlights • Synthesis of nano SiO x from natural silica by facile ball milling. • Exceptional long-term cycling stability up to 2000 cycles was demonstrated. • Superb structural stability derived from intrinsic porosity and the grown stable SEI. • Blending with graphite exhibited application feasibility with high areal capacity. [ABSTRACT FROM AUTHOR]

Owing to their multiple redox couples, titanium–niobium-based oxides are still considered promising candidates for use as anodes for safe, rechargeable lithium ion batteries with high energy and power densities. Titanium–niobium-based oxide electrodes have, however, exhibited relatively poor cycling performance as a result of pulverization. In this study, we report on a simple two-step solid-state reaction route for producing hybrid composites of Ti 2 Nb 10 O 29 (TNO) anchored on reduced graphene oxide (RGO), and the electrochemical performance of the resulting TNO/RGO composites. Solid-state reactions enable both the formation of TNO and the uniform distribution of RGO in the TNO/RGO composites. The TNO/RGO composites exhibited discharge and charge capacities of 261 and 256 mAh g −1 , respectively, with much better cycling performance (182 mAh g −1 after the 50th cycles) and rate capability (165 mAh g −1 at a current density of 500 mA g −1 ) compared to the pure TNO. [ABSTRACT FROM AUTHOR]

This work explores low cost methods for the preparation of Si/nano-graphite sheets (NanoGs) composite materials for Li ion battery. The Si/NanoGs composites are prepared by magnesium thermal reduction of mechanical mixture of fumed SiO 2 and NanoGs under Ar atmosphere. The structure of the samples is characterized by XRD, Raman spectroscope, SEM, and HRTEM. The results show that highly crystallized Si nanoparticles with a sheet-like morphology are uniformly distributed on the surface of NanoGs (both edge and a-b plane). The average diameter of Si nanoparticles is ∼20 nm. Electrochemical characterization shows that an electrode has an initial lithium storage capacity of 1702.9 mAh g −1 at a current of 100 mA g −1 . The storage capacity decreases to 975.7 mAh g −1 after 100 cycles. Since cheap commercial fumed SiO 2 and graphite are used and the process is simple and easy to scale up, with further improvement, the method has potential for use in large scale production of high energy density Si/NanoGs anode materials at low cost. [ABSTRACT FROM AUTHOR]

Small amount of reduce graphene oxide (rGO) nanosheets modified Li 4 Ti 5 O 12 nanoparticles composite has been synthesized by a facile and environmental in-situ hydrothermal reaction with subsequent annealing. The small amount of rGO (only 1.2 wt. %) greatly improves the whole morphology and electrochemical performance of composite. The nanoparticles uniformly grow on the rGO nanosheets effective suppressing the agglomeration and enhancing the specific surface area. Meanwhile, the special discharge capacity is 187 mAh g −1 at 1 C and the high rates discharge capacity is 128 mAh g −1 at 80 C (discharge-charge time only 33s). In particular, the cells remain in good work condition after 2000 cycles at 80 C, which credibly evidence the excellent electrochemical performance as an anode for high-power LIBs. [ABSTRACT FROM AUTHOR]

Flower-like hydrogenated TiO 2 (B) nanostructures have been synthesized via a facile solvothermal approach combined with hydrogenation treatment. The obtained TiO 2 (B) nanostructures show uniform and hierarchical flower-like morphology with a diameter of 124 ± 5 nm, which are further constructed by primary nanosheets with a thickness of 10 ± 1.2 nm. The Ti 3+ species and/or oxygen vacancies are well introduced into the structures of TiO 2 (B) after hydrogen reduction, resulting in an enhancement in the electronic conductivity (up to 2.79 × 10 −3 S cm −1 ) and the modified surface electrochemical activity. When evaluated for lithium storage capacity, the hydrogenated TiO 2 (B) nanostructures exhibit enhanced electrochemical energy storage performances compared to the pristine TiO 2 (B) nanostructures, including high capacity (292.3 mA h g −1 at 0.5C), excellent rate capability (179.6 mA h g −1 at 10C), and good cyclic stability (98.4% capacity retention after 200 cycles at 10C). The reasons for these improvements are explored in terms of the increased electronic conductivity and the facilitation of lithium ion transport arising from the introduction of oxygen vacancies and the unique flower-like morphologies. [ABSTRACT FROM AUTHOR]

Abstract: In this manuscript, we present a facile and friendly wet chemical method to prepare monodisperse SnO2 nanocrystals assembled on reduced graphene oxide (RGO). Aided with sodium dodecyl sulfonate, small SnO2 nanoparticles (∼5 nm) are deposited onto the flexible support evenly and tightly. A cheap compound, urea, is used for the controlled precipitation of SnO2 and the reduction of graphene oxide. When tested as the anode material, the hybrid composite electrode delivers excellent cyclability at high current density, such as high reversible capacity over 1000mAhg−1 after 400 cycles at 0.5Ag−1 and ∼560mAhg−1 after 400 cycles at 1Ag−1. The composites also exhibit superior rate capability varying from 0.1 to 4Ag−1, and possess capacity of 423mAhg−1 at 4Ag−1. This synthesis strategy seems to be suitable for industrial production and can also be extended to produce a variety of metal oxide/RGO composites. [Copyright &y& Elsevier]

Abstract: In this study, size effect of NiO particles has been studied as the anode material of lithium ion battery. It is found that NiO nanoparticles synthesized in confined space of ordered mesoporous silica behave anomalous high capacity and higher energy efficiency than sub-micro-sized NiO does. The higher energy efficiency is resulted from the reduction of the hysteresis loop between charge and discharge voltage plateaus, the main drawback of conversion reaction-based metal oxide anode materials. The interesting behavior is proposed to be the reversible formation/dissolution of solid electrolyte interphase (SEI) layers associated with 3-D porous, originally nanostructured NiO electrode that is able to remain stable during charge–discharge process. [Copyright &y& Elsevier]

Abstract: Carbon-coated Li3VO4 sample is synthesized by a simple sol–gel method. X-ray diffraction and X-ray photoelectron spectroscopy results show that single-phase Li3VO4 can be obtained in a reducing atmosphere with the valence of vanadium of +5. The final product sintered at 650 °C demonstrates a favorable electronic conductivity with 6.12% residual carbon. Electrochemical testing shows that the carbon-coated Li3VO4 sample display a discharge capacity of 662.6 mAh g−1 and 507.4 mAh g−1 at 0.18C in the first and the second cycle, respectively, and a reversible capacity (charge capacity) of ∼480.0 mAh g−1 can be obtained in the second cycle. Furthermore, the discharge–charge capacity of the sample can retain ∼180 mAh g−1 and ∼90 mAh g−1 at 12C and 40C, respectively. [Copyright &y& Elsevier]

Abstract: A new method for a facile synthesis of nano-silicon/carbon mesoporous composite is proposed. Silicon nanoparticles can be obtained through the magnesium silicide reduction of amorphous silica using high energy mechanical milling process. And mesoporous carbon matrix is fabricated via simple carbon coating method on Si nanoparticles followed by chemical etching of preexisting magnesium oxide nano-particles. This nano-silicon/carbon mesoporous composite electrode shows an excellent electrochemical performance as an anode for lithium ion batteries, achieving a reversible capacity of c.a. 1600 mAh g−1 over 50 cycles at a current of 1.0 A g−1 and superior rate capabilities with reversible capacity of about 1530 mAh g−1 at a discharge current density of 3 A g−1. [Copyright &y& Elsevier]

Abstract: The composite of manganese monoxide and multi-walled carbon nanotubes (MnO/MWNTs) is prepared hydrothermally by MWNTs and KMnO4 followed with a sintering process. After reducing KMnO4 as the reductant, the leftover MWNTs are found randomly distributed in the final MnO rods forming a conducting network. More importantly, they can buffer the volume change of MnO during lithium incorporation/extraction. As a result, the rate capability and cycling performance of MnO as an anode material for lithium ion batteries are significantly improved. The MnO/MWNTs composite shows a reversible capacity as high as 770.6 mA h g−1 and 455.3 mA h g−1 at the current density of 7.21 mA g−1 and 310.23 mA g−1 respectively between 0.01 and 3.5 V (vs. Li/Li+ hereafter). Furthermore, the capacity retention is over 92.4% after 200 cycles at 216.14 mA g−1 between 0.01 and 3.0 V. [Copyright &y& Elsevier]

Abstract: Reduced graphene oxides have been prepared via controllably thermal and chemical reduction processes. The structure, surface chemistry and electrochemical behaviors of reduced graphene oxides are investigated by Raman spectroscopy, N2 adsorption, temperature-programmed desorption, Fourier-transform Infrared spectroscopy, X-ray photoelectron spectroscopy, as well as charge/discharge measurements. The enhanced reversible capacity of reduced graphene oxides is attributed to specific functionalities rather than to exceptional large specific surface area or structure defect. The contributed capacities at potential higher than 1.5 V and in region of 0.8–1.5 V are attributed dominantly to phenol groups and cyclic edge ether groups, respectively. These findings may be beneficial to the material design of graphene-based anode materials with high energy density. [Copyright &y& Elsevier]

Abstract: An efficient synthesis is used for the first time to prepare CuO/reduced graphene oxide nanocomposite anode materials for lithium ion batteries. Initially, copper oxide (CuO) nanoparticles are synthesized via a simple, facile and inexpensive microwave-assisted method within short reaction times (<20 min) and subsequent heat treatment at 500 °C for 5 h. The obtained pure CuO nanoparticles are mixed with 10 wt% of graphene nanosheets by the use of spex mill for 1 min. By short-time spex-milling, a unique CuO/reduced graphene oxide nanocomposite is obtained with a microstructure of multi-scale CuO nanoparticles homogeneously dispersed in a graphene matrix. The synthesized samples are characterized using X-ray diffraction and field-emission transmission electron microscopy studies. The spex-milled nanocomposite anode exhibits better electrochemical performance with higher reversible capacity and excellent cyclability in comparison with pure CuO nanoparticles. The initial discharge capacity of the pure CuO nanoparticles and their nanocomposite are 785.2 mAh g−1 and 1043.3 mAh g−1 with reversible capacity retention of 392.1 mAh g−1 and 516.4 mAh g−1 after 45 cycles respectively. The excellent electrochemical performance of CuO/reduced graphene oxide nanocomposite can be attributed to their unique structures, which intimately combine the conductive graphene nanosheets network with uniformly dispersed CuO nanoparticles. [Copyright &y& Elsevier]

Abstract: Magnetite (Fe3O4)/carbon core–shell nanotubes have been successfully synthesized by partial reduction of monodispersed hematite (Fe2O3) nanotubes with carbon coating. Fe2O3 is completely converted to Fe3O4 during the reduction process and a thin carbon layer is continuously coated on the surface of Fe3O4 with the nanotube morphology reserved. The Fe3O4/carbon core–shell nanotubes exhibit superior electrochemical properties as anode material for lithium-ion batteries compared with the Fe2O3 and Fe3O4 nanotubes. The Fe3O4/carbon core–shell nanotubes electrode shows a large reversible capacity up to 938 mAh g−1 as well as improved cycling stability and excellent rate capability. The promising anode performance of the Fe3O4/carbon core–shell nanotubes can be attributed to their tubular morphology and continuous carbon coating, which provide improved structural stability and fast charge transport. [Copyright &y& Elsevier]

Abstract: In this work, a novel composite consisting of nanosized silicon highly dispersed within the porous, elastic and conductive oxide/carbon matrix has been developed as an anode candidate for lithium ion batteries. The composite was prepared by a mechanochemical reaction between SiO and Li under ball milling followed by a carbon coating using the pyrolysis of poly(vinyl chloride)–co-vinyl acetate. The porous structure can effectively suppress the volume change of silicon during the electrochemically Li-alloying process. No obvious capacity fading was observed up to 100 cycles with a stable capacity of 620mAhg−1. The factors influencing the microstructure and the electrochemical behavior of the composite were discussed. [Copyright &y& Elsevier]

Abstract: Composite consisting of nanosized silicon, Li4SiO4 and other lithium-rich components was synthesized using high energy mechanical milling (HEMM) method. The reactive milling of SiO with lithium metal resulted in the oxidation of lithium and silicon, and reduction of SiO. X-ray diffraction (XRD) and high-resolution transmission electron microscope (HRTEM) were used to determine the phases present in the composite. In addition, cyclic voltammetry (CV), along with constant current discharge/charge tests, was used to characterize the electrochemical properties of the resultant material. Compared with pure SiO and pure silicon as anode materials, the as-prepared composite demonstrated larger capacity and superior cyclability even at high C-rate. [Copyright &y& Elsevier]

The incorporation of ultrafine SnO 2 particles inside N-doped ordered mesoporous carbon (N-CMK3) is suggested as a method to prepare an ultrastable anode material for Li-ion batteries. Sn nanoparticles formed by chemical reduction of SnCl 4 inside N-CMK3 pores are spontaneously reoxidised by dissolved oxygen, resulting in the formation of ultrafine SnO 2 inside N-CMK3 pores. This SnO 2 @N-CMK3 exhibits superior capacity, cyclability, and rate capability. Over 100 cycles at a rate of 0.1C, SnO 2 @N-CMK3 maintains a specific capacity of 635 mAh g−1, corresponding to a capacity retention of 86.6%. Over 1000 cycles at the rate of 0.5C, SnO 2 @N-CMK3 can deliver a capacity of 433 mAh g−1. At an ultrahigh rate of 5C, SnO 2 @N-CMK3 still delivers a capacity higher than that of commercial graphite. The full cell, composed of an SnO 2 @N-CMK3 anode, LiCoO 2 cathode, and sacrificial Li electrode, presents excellent performance, better than previous reports of Li-ion cells. By employing a sacrificial Li electrode, the issue related to the low Coulombic efficiency of SnO 2 @N-CMK3 in the first few cycles and the pre-lithiation SnO 2 @N-CMK3 electrode can be successfully addressed. Image 1 • Ultrafine SnO 2 particles are filled inside mesopores of N-CMK3. • SnO 2 @N-CMK3 exhibits the reversible capacity of 635 mAh g−1 at the rate of C/10. • An original three-electrode full cell using SnO 2 @N-CMK3 anode is designed. • Sacrificial Li electrode in the full cell improves coulombic efficiency. • The full cell delivers 608 mAh g−1 with 83.8% retention over 200 cycles. [ABSTRACT FROM AUTHOR]