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Lithium-ion batteries are widely used in electric vehicles, energy storage power stations, and many other applications. Accurate and reliable monitoring of battery health status and remaining capacity is the key to establish a lithium-ion cell management system. In this paper, based on a Bayesian optimization algorithm, a deep neural network is structured to evaluate the whole charging curve of the battery using partial charging curve data as input. A 0.74 Ah battery is used for experiments, and the effect of different input data lengths is also investigated to check the high flexibility of the approach. The consequences show that using only 20 points of partial charging data as input, the whole charging profile of a cell can be exactly predicted with a root-mean-square error (RMSE) of less than 19.16 mAh (2.59% of the nominal capacity of 0.74 Ah), and its mean absolute percentage error (MAPE) is less than 1.84%. In addition, critical information including battery state-of-charge (SOC) and state-of-health (SOH) can be extracted in this way to provide a basis for safe and long-lasting battery operation. [ABSTRACT FROM AUTHOR]

A three-dimensional carbon-coated SnO2/reduced graphene oxide (SnO2/RGO/C) foam has been prepared by using glucose as the carbon source and cross-linking agent through a one-step hydrothermal process followed by freeze drying. The foam, as a free-standing anode for lithium-ion batteries, exhibits a large capacity and excellent cycling stability (717 mAh g−1 after 130 cycles at 100 mA g−1). The outstanding electrochemical performance could be related to the synergistic effect between the nano-sized high-capacity SnO2, the excellent electronic conductivity and large specific surface area of RGO, and the carbon coating layer, which could enhance the bonding strength of SnO2 nanoparticles and RGO nanosheets, keep the structural integrity, and increase the electronic conductivity. The strong interaction between SnO2 and RGO, the high electronic conductivity, and the porous structure of the composite result in high electrochemical activity and stable cycling performance as a binder-free anode for lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Li3VO4 is a potential anode for Li-ion batteries owing to its safe discharge plateau and high capacity, but the reported reversible capacity is still far from its theoretical value (592 mAh g−1). Here, for the first time, a Li3VO4 anode is reported with reversible capacity approaching the theoretical value. Li3VO4 aggregates hybridized with carbon (Li3VO4/C) are first fabricated, and then dramatically transform into well dispersed Li3VO4 nanocrystals (NCs) anchoring on carbon nanoflakes (NFs) by electrochemical reconstruction. In the Li3VO4/C NC-on-NF structures, the small-sized Li3VO4 NCs, the flexible carbon NFs, and the good dispersity provide high Li-ion storage, electronic conductivity and stability, respectively. Resultingly, outstanding electrochemical performance of the Li3VO4/C is achieved with discharge and charge capacities of 542 and 541 mAh g−1 after 300 cycles at a specific current of 150 mA g−1. After 1000 cycles at a specific current of 2000 mA g−1, the discharge and charge capacities are maintained at 422 and 421 mAh g−1. When matching with a 4 V cathode, the specific energy density of the Li3VO4/C is 4.2 times of Li4Ti5O12 and 1.2 times of graphite, and the volumetric energy density is 3.2 times of Li4Ti5O12 and 1.4 times of graphite. [ABSTRACT FROM AUTHOR]

A novel in situ electrochemical reconstruction occurs in NiV3O8/natural graphite electrodes, which results in excellent electrochemical performance. After repeated rate performance from 0.16 to 3.1 A g−1 over 320 cycles, the specific capacity can restore well and shows no obvious attenuation in the subsequent 360 cycles. [ABSTRACT FROM AUTHOR]

The high-efficient, controllable, and non-destructive chemical prelithiation of VO 2 (B) electrodes have been successfully accomplished via a Li-BP derivative/THF reagent, gaining a high-energy and long-life Li-ion battery. [Display omitted] • A non-destructive chemical prelithiation of VO 2 (B) anodes was achieved using a reductive Li-arene reagent. • The prelithiated VO 2 (B) anode exhibited an initial Coulombic efficiency of nearly 100 %. • The SEI layer formed on the prelithiated VO 2 (B) electrode contained a variety of favorable functions. • The Prelithiation VO 2 (B)||NCM811 full cell realized a rise in the energy density of at least 20 %. VO 2 (B) stands as a promising anode material, comparable to the disordered rock-salt phase Li 3+x V 2 O 5 , owning to its ease of preparation, suitable redox potential, and remarkable rate capability. However, the practical application of VO 2 (B) anodes faces substantial limitations due to its low initial coulombic efficiency (ICE) and instability of solid electrolyte interface (SEI) layer during cycling. In this study, we introduce a highly efficient, controllable, and non-destructive chemical prelithiation method utilizing a reductive Li-arene reagent, formed by dissolving Li-metal to THF solutions containing biphenyl derivatives. This method enables the VO 2 (B) anode to achieve an ICE of nearly 100 %. The investigation on the chemical composition and mechanical properties of SEI layers reveals that the prelithiated VO 2 (B) electrode contains a more favorable LiF component, fewer adverse byproducts, and exhibits a thinner thickness with high structural strength. Kinetic analysis demonstrates that the prelithiation treatment accelerates the diffusion of lithium ions, reduces interfacial reaction resistances, and maintains interface stability during cycling. To demonstrate the practical application, we assemble a well-designed Prelithiation VO 2 (B)||NCM811 full cell, achieving an enhancement in the energy density of at least 20 %. This work underscores the potential of prelithiated VO 2 (B) electrodes for developing lithium-ion batteries (LIBs) with high-safety and high-energy/power density. [ABSTRACT FROM AUTHOR]

Abstract: The electrochemical performance of LiFePO4/C samples synthesized by different carbon sources varies considerably, the structural difference of residual carbon in LiFePO4/C accounts for the performance variation. Higher performance is associated with a larger ratio of graphitic carbon, which exhibits better electronic conductivity than amorphous carbon. To improve the electronic conductivity, we prepared LiFePO4/(C+G) composites by a one-step solid-state method, in which natural graphite is used as reducing agent and conducting additives. The samples were characterized by X-ray diffraction (XRD), high-resolution transmission electron microscope (HRTEM), Raman microprobe spectroscope and other electrochemical methods. The results show that reversible capacity and rate performance of LiFePO4 are improved considerably by the two-phase carbon coating. Therefore, LiFePO4/(C+G) composites are a promising candidate for lithium ion batteries. [Copyright &y& Elsevier]

Abstract: A novel nano-Si dispersed composite containing lithium-rich component (lithium orthosilicate, etc.) has been prepared and investigated as a potential anode material for lithium-ion batteries. The composite was synthesized by mechanochemical reduction of SiO using lithium metal as reducing agent and graphite as grinding aid, further vacuum heat-treatment was performed to improve interfacial stability between different components. Compared with pure SiO and intrinsic silicon electrodes, the as-obtained composite electrode exhibited greatly improved cycling performance with a remarkable value of the first coulombic efficiency. The superior electrochemical properties were attributed to small absolute volume changes of nano-silicon particles, highly distribution of silicon phase and better buffering action of lithium-containing components. [Copyright &y& Elsevier]

• Carbon encapsulated MnMoO 4 microrods are realized in this work. • The MnMoO 4 @C microrods show excellent performance in SIBs and PIBs. • A sodium ion capacitor (SIC) based on MnMoO 4 and Na 3 V 2 (PO 4) 3 is employed. • The SICs display energy densities of 168 and 88 Wh kg−1 at 240 and 4000 W kg−1. Mixed transition metal molybdate oxides (AMoO 4 where A = Ni, Co, Fe, Mn) manifest high capacities (≈ 980 mAh g −1) via the multiple redox reactions, with the Mo ranging from Mo6+ to Mo0. What's more, this dual metal oxides exhibit superior performance to single transition metal oxide, as a result of the synergic effects of multiple transition metals and the better electrical conductivity than that of single metal oxide. Bimetallic MnMoO 4 shows satisfied performance in lithium ion batteries (LIBs), but its performance in sodium ion batteries (SIBs) and potassium ion batteries (PIBs) has not been exploited. On account of this, a carbon encapsulated MnMoO 4 microrod is designed as the anode material in SIBs and PIBs. It is detected that the electrochemical performance of the carbon encapsulated MnMoO 4 microrods in SIBs is highly boosted with respect to the bare MnMoO 4. In view of the pseudocapacitance effect of MnMoO 4 microrods in SIBs, a sodium ion capacitor (SIC) based on MnMoO 4 capacitor-type anode and Na 3 V 2 (PO 4) 3 battery-type cathode is employed and displays high energy densities of 168 and 88 Wh kg−1 at 240 and 4000 W kg−1. [Display omitted] [ABSTRACT FROM AUTHOR]

Carbon coated isotropic natural graphite spheres (INGS/C) has been prepared by spray granulation using the by-product of spherical natural graphite (i.e., superfine graphite powders) as starting materials. In INGS/C, small graphite flakes are packed in disordered orientation and form an isotropic structure, which may effectively reduce local stress concentration appearing in the process of Li + insertion/extraction. The pyrolytic carbon decomposed from polyvinyl alcohol (PVA) and citric acid is connecting the small graphite flakes and coating on the surface of INGS, respectively, thus forms a continuous conductive network to improve the electron transmission and maintain the micro-structural integrity of isotropic natural graphite spheres as well. With the help of synergetic effect between the isotropic structure of INGS and the continuous conductive network, the INGS/C electrode exhibits superior rate capability of 346 mA h g −1 at 3 C at low potential below 0.25 V. [ABSTRACT FROM AUTHOR]

Porous Si/C/reduced graphene oxide (Si/C/rGO) microspheres have been prepared by the spray drying and subsequent carbonization process using the polyvinyl alcohol (PVA) as cross-linking agent. PVA plays an important role in the spray drying process. The designed micrometer-size reduced graphene oxide wrapped Si/C ball structure offers a buffer space for the volume change of Si during the charge-discharge process. Double carbon layers can effectively protect the Si core and improve the cycling stability of the electrode. The fabricated Si/C/rGO microspheres as anode for lithium ion batteries exhibit a high reversible capacity of 928 mAh g − 1 after 70 cycles at a current density of 100 mA g − 1 , good rate capability and cycling stability. [ABSTRACT FROM AUTHOR]

Temperature dependent fabrication of NiCr 2 O 4 is studied and the application of the as-prepared NiCr 2 O 4 in both half-cell with Li metal anode and full-cell with LiFePO 4 cathode are assessed. When mixing with natural graphite (NG), the NiCr 2 O 4 obtained at 550 °C can deliver initial charge and discharge capacities of 795 and 1275.5 mAh g −1 at a specific current of 150 mA g −1 , maintaining of 939 and 955 mAh g −1 after 140 cycles. In contrast, after 140 cycles at the same specific current, the NiCr 2 O 4 obtained at 450 °C and 650 °C can maintain charge/discharge capacities of 800/814 and 523/528 mAh g −1 , respectively. When matching with a LiFePO 4 cathode, The NiCr 2 O 4 /NG (obtained at 550 °C) electrode delivers initial discharge capacity of 285 mAh g −1 , which maintains of 106 mAh g −1 after 50 cycles at a specific current of 100 mA g −1 . [ABSTRACT FROM AUTHOR]

Flexible and lightweight reduced graphene oxide wrapped Si/carbon fibers paper (Si@RGO/CFP) anodes have been prepared by pyrolysis of the common filter paper, which was soaked into the suspension containing graphene oxide and Si. The reduced graphene oxide wrapped Si nanoparticles (Si@RGO) homogeneously distributed on the interlaced carbon fibers and void among the carbon fibers. The Si@RGO/CFP as a flexible binder-free electrode exhibits an initial reversible capacity of 2055 mAh g −1 and 1092 mAh g −1 after 100 cycles for Si@RGO at 100 mA g −1 along with good rate performance. The superior electrochemical performance of the Si@RGO/CFP is attributed to the interconnected carbon fibers substrate, which provides electronic conduction pathways and works as mechanical support, and the void among carbon fibers accommodates the volume changes of Si and maintains the integrity of the electrode materials. [ABSTRACT FROM AUTHOR]

NiO/C-Ni composite is prepared via a facile hydrothermal pretreatment and subsequent annealing, which shows excellent cycle stability and superior rate capability as binder free anode for lithium ion batteries. It delivers initial discharge and charge capacity of 971 and 672 mAh g −1 at 0.3C, maintaining of 700 and 669 mAh g −1 after 70 cycles. After 60 cycles at various rates from 0.3 to 12C, the discharge capacity of the NiO/C-Ni electrode can gradually restore when reverting the rate to 0.3C, maintaining of 692 mAh g −1 after 10 cycles. The impressive electrochemical performance demonstrates great potential of the NiO/C-Ni as anode for high performance lithium ion batteries. [ABSTRACT FROM AUTHOR]

In view of the low cost and comparable properties with lithium ion batteries (LIBs), sodium ion batteries (SIBs) are considered to be the most hopeful candidate or supplement for LIBs. To date, conversion-type transition metal phosphides (TMPs) are pursued as vital anode materials in SIBs since their high theoretical capacity and low redox potential compared to their oxides and sulfides, yet still suffer from unfavorable electrical conductivity and poor reaction kinetices. In this regard, for the first time, we put forward a self supported Fe 2 P hierarchical microsphere arrays with Se doping to optimize the performance of transition metal phosphides. As expected, the Se doped Fe 2 P (Fe 2 P 0.8 Se 0.2) arrays obviously show superior performnace than bare Fe 2 P, delivering a high reversible capacity of 312.5 mAh g−1 at 2000 mA g−1, and sustaining a capacity of 395.1 mAh g−1 at 1000 mA g−1 experiencing 1000 cycles. Combined with the experiment and in-depth DFT calculation results, it can be concluded that the Se doping protocol could largely modulate the charge density distribution and enhance Na adsorption ability thereafter minimize Na+ diffusion energy barrier, enabling elevated electrochemical performance. [Display omitted] • A self supported Fe 2 P hierarchical microsphere arrays with Se doping is designed. • The Se doped Fe 2 P arrays shows superior performnace than bare Fe 2 P. • Se doping into Fe 2 P could largely modulate the charge density distribution. • Se doping into Fe 2 P protocol could minimize Na+ diffusion energy barrier. [ABSTRACT FROM AUTHOR]

High capacity and superlong cycle life of Li 3 VO 4 have been actualized via carbon hybridization and N doping. The Li 3 VO 4 /N doped C (Li 3 VO 4 /N–C) that fabricated via an in situ carbonization method based on an intermedial solution phase delivers initial discharge and charge capacities of 686 and 540 mAh g −1 at a specific current of 0.15 A g −1 , which maintain of 538 and 536 mAh g −1 after 800 cycles, showing excellent cycle stability. Meanwhile, the Li 3 VO 4 /N–C exhibits superior rate performance and long life performance. After 150 cycles at various specific currents from 0.1 to 2.0 A g −1 , the discharge and charge capacities can restore 100% when reverting the specific current to 0.1 A g −1 . After 1100 cycles at a specific current of 2.0 A g −1 , the discharge and charge capacities can maintain of 340 and 337 mAh g −1 , showing no capacity attenuation in cycling. [ABSTRACT FROM AUTHOR]

Li 3 VO 4 /N-doped graphene with unique architecture of Li 3 VO 4 nanoparticles embed in N-doped graphene is successfully prepared via a facile method, which shows superior electrochemical performance as anode for Li-ion batteries. At a specific current of 0.15 A g −1 , it delivers discharge and charge capacities of 550 and 429 mAh g −1 in the initial cycle, which maintain of 478 and 476 mAh g −1 after 100 cycles. After 150 cycles at various specific currents from 0.1 to 2.0 A g −1 , the discharge capacity can restore to 487 mAh g −1 when reverting the specific current to 0.1 A g −1 . Meanwhile, even after 900 cycles at a specific current of 2.0 A g −1 , the Li 3 VO 4 /N-doped graphene electrode can deliver discharge and charge capacities of 195 and 193 mAh g −1 . [ABSTRACT FROM AUTHOR]

Coordinated electrochemical effect between Li 3 VO 4 and NiO occurs in Li 3 VO 4 /NiO/Ni electrodes owing to the close potential regions of lithiation and delithiation for Li 3 VO 4 and NiO. Remarkably, Li 3 VO 4 /NiO/Ni with bottom nanowalls and upper micro-flowers architecture undergoes a novel coordinated electrochemical reconstruction owing to well coordinated morphology variation of Li 3 VO 4 and NiO in lithiation and delithiation process, which leads to the formation of a new symmetrical porous architecture in cycling, resulting in superior electrochemical performance. At a specific current of 70 mA g −1 , it exhibits discharge and charge capacity of 860 and 631 mAh g −1 in the initial cycle, maintaining of 612 and 604 mAh g −1 after 100 cycles. After 60 cycles at various specific currents from 54 to 2700 mA g −1 , the discharge and charge capacity can restore to 612 mAh g −1 when reverting the specific current to 54 mA g −1 . [ABSTRACT FROM AUTHOR]

NiCr 2 O 4 is successfully prepared via hydrothermal pretreatment and subsequent sintering, which shows excellent electrochemical performance as a new anode material for lithium ion batteries with natural graphite adding and sodium alginate binder. At a specific current of 70 mA g −1 , it delivers charge and discharge capacities of 465.5 and 919.8 mAh g −1 in the initial cycle, which gradually increases along with cycle number owing to an electrochemical reconstruction in cycling. After 100 cycles, the charge and discharge capacities are 582.9 and 592.5 mAh g −1 , respectively. Furthermore, it is testified that natural graphite adding can effectively improve the electronic conductivity of the NiCr 2 O 4 electrode, and an appropriate amount of natural graphite is beneficial to improve the specific capacity and cycle stability of the electrode owing to a coordinated electrochemical reconstruction between NiCr 2 O 4 and natural graphite in cycling. [ABSTRACT FROM AUTHOR]

CoV 2 O 6 /natural graphite electrode with sodium alginate binder is prepared, which shows excellent electrochemical performance as anode for Li-ion batteries. It exhibits initial discharge and charge capacity of 902 and 638 mAh g −1 at a specific current of 110 mA g −1 . After 100 cycles, the discharge and charge capacity maintain of 669 and 665 mAh g −1 , respectively. The charge/discharge mechanism of CoV 2 O 6 is also studied, suggesting a structure variation in discharging, which involves the initial formation of LiV 2 O 5 and Co 3 V 2 O 8 , the subsequent transition from Co 3 V 2 O 8 to Li x V 2 O 5 and CoO, and the later reduction of CoO into Co. The structure variation of Co 3 V 2 O 8 accompanies by an amorphization process, which maintains in the subsequent discharging and charging process. [ABSTRACT FROM AUTHOR]

NiO nanowalls are directly grown on porous Ni foam via a facile electrochemical corrosion method and subsequent annealing, which show excellent cycle stability and rate capability as anode for lithium ion batteries. It delivers initial discharge and charge capacity of 1029 and 761 mAh g −1 at 0.15C, maintaining of 721 and 704 mAh g −1 after 100 cycles. After 60 cycles at various rates from 0.06 to 10C, the discharge capacity of the NiO/Ni can gradually restore when lowering the charge/discharge, finally arriving at 745 mAh g −1 after 30 cycles at 0.06C. The excellent electrochemical performance of the NiO/Ni electrode is relevant to a novel electrochemical reconstruction in cycling, which can be described as the initial formation of a large number of nanosized particles and the subsequent reassembly of these nanoparticles into a unique porous architecture. [ABSTRACT FROM AUTHOR]

Li 3 VO 4 nanoparticles with mean size about 100 nm are uniformly deposited on the surface of natural graphite via a quasi sol gel method. The electrochemical performance of the Li 3 VO 4 /natural graphite composite as anode for lithium ion batteries is studied via galvanostatic battery testing, which shows excellent cycle stability and rate capability. At a specific current of 156 mA g −1 , it delivers discharge and charge capacity of 579 and 427 mAh g −1 in the initial cycle, which maintain of 469 and 468 mAh g −1 after 100 cycles. After 60 cycles at various specific currents from 234 to 11,719 mA g −1 , the discharge capacity can restore to 450 mAh g −1 when reverting the discharge/charge current to 234 mA g −1 . It is demonstrated that natural graphite has important effect on the electrochemcial performance of the composite electrode, and an appropriate amount of natural graphite is beneficial to reduce the charge transfer resistance and maintain stable charge transfer process in cycling. [ABSTRACT FROM AUTHOR]

Highlight: [•] we fabricated Li3VO4/Ni composite via a unique two-step method [•] the Li3VO4/Ni electrode shows good cycle stability and rate capability [•] the Li3VO4/Ni electrode shows stable charge transfer and Li-ion diffusion coefficient [•] the Li3VO4/Ni electrode shows highly reversible lithiation/delithiation process [ABSTRACT FROM AUTHOR]

Abstract: Li3VO4 is fabricated by a facile hydrothermal method and subsequent annealing treatment. The electrochemical performance and the possible charge/discharge mechanism of the as-prepared Li3VO4 as anode for Li-ion battery are firstly studied. Galvanostatic battery testing shows that the Li3VO4 electrode exhibits excellent cycle stability and rate capability. At a current density of 0.25 C, it delivers initial discharge and charge capacity about 624 and 481 mAh g−1, respectively, which maintains of 398 and 396 mAh g−1 after 100 cycles. After 60 cycles at various rates from 0.2 to 4.0 C, the discharge capacity can restore 98% when lowering the charge/discharge rate to 0.2 C. A possible redox reaction mechanism is proposed to interpret the lithiation/delithiation process of Li3VO4 according to experimental observations. The electrochemical reaction kinetic of the Li3VO4 electrode is studied by cyclic voltammetry measurement at various scan rate, which indicates the anodic and cathodic peak currents show linear dependence on the square root of scan rate from 0.3 to 1.0 mV s−1, suggesting a lithium ion diffusion controlled mechanism in the charge/discharge process. [Copyright &y& Elsevier]

Highlights: [•] We prepared Cu2O–Cu composite architecture via an electrochemical corrosion method. [•] We explored the utilization of electrochemical corrosion of metal in Li-ion batteries. [•] The obtained Cu2O–Cu electrode shows excellent cycle stability and rate capability. [•] The effect of corrosion condition on electrochemical performance of Cu2O–Cu was studied. [ABSTRACT FROM AUTHOR]

Abstract: Novel massif-like Cu x O nanostructure was directly growing on Cu foam via a facile thermal oxidation method in air atmosphere. The massifs are about 5μm in mean diameter and 4μm in mean height, which consist of a large number of nanoparticles with mean size about 100nm. Cu x O nanowires that evolve from the particles locate at the laps of the massifs. Galvanostatic battery testing shows that the Cu x O/Cu electrode exhibits excellent cycle stability and rate capability. The charge and discharge capacities are both 1.8mAhcm−2 after 100 cycles under a discharge/charge rate of 0.35C. After testing at various rates from 0.2 to 12C over 50 cycles, the 5th-cycle discharge capacity can resume well when lowering the discharge/charge rate to 0.2C. The performances are testified due to a novel electrochemical activation effect that induces the reconstruction of porous forest-like morphology in cycling. [Copyright &y& Elsevier]

Abstract: Porous NiO/Ni foam electrode is fabricated by a simple two-step method. Firstly, nickel hydroxide hydrate nanoflakes are deposited on Ni foam via a chemical liquid deposition (CLD) method. Then NiO/Ni architecture is obtained by subsequent graft growth in air atmosphere at 350°C. Galvanostatic battery testing shows that NiO electrode exhibits fine capacity retention and good rate performance. It exhibits high initial discharge and charge capacity of 1.94 and 1.36mAhcm−2, maintaining of 1.41 and 1.38mAhcm−2 after 140 cycles under a discharge/charge rate of 0.4C. It delivers high discharge capacity retention of 70% (comparing with that of 0.2C) even at a high rate of 2.5C. After that, the discharge capacity can gradually resume along with the decrease of discharge/charge rate, showing capacity retention of 105% when lowering the discharge/charge rate to 0.2C. The fine electrochemical performance of NiO/Ni is due to the maintenance of porous architecture and the prevention of active nano-sized NiO from aggregation in cycling, which is relevant to both the interweaved structure of NiO nanoflakes and the graft growth between NiO and Ni. [Copyright &y& Elsevier]

Abstract: Recent experiments showed beneficial influence of vanadium doping on the electrochemical performance of lithium iron phosphate (LiFePO4) cathode materials. First-principles calculations have been performed to investigate the stability, electronic structure and lithium diffusivity of vanadium-doped LiFePO4 and to elucidate the origin of such improvement. It is found that vanadium prefers occupying Fe sites and leads to additional density of states within the intrinsic bandgap. By the nudged elastic band method, we show that the barrier of Li ions diffusion along the one dimensional channel in both LiFePO4 and FePO4 phases can be effectively reduced by vanadium doping. Structural analysis shows the lower diffusion barrier ties closely to a volumetric expansion of the diffusion channel. [Copyright &y& Elsevier]

Abstract: Silicon/carbon composite was prepared by an in situ carbon-thermal reduction method that used pyrolyzed carbon to reduce silicon monoxide. The composite was confirmed by X-ray diffraction and high-resolution transmission electron microscope. It was demonstrated that nano-scale (ca. 20nm) crystal silicon particles were obtained and simultaneously distributed in amorphous carbon matrix. Compared with the silicon/carbon composite having commercial nano-silicon particles (50–100nm), the as-prepared composite displayed a good capacity retention. The superior electrochemical properties were attributed not only to small volume changes of silicon particles, but also to better buffering effect of matrix and better electrical contact between the matrix and silicon particles. [Copyright &y& Elsevier]

• Large-area petal-like V 2 O 5 thin nanosheets have been successfully fabricated. • The formation mechanism of V 2 O 5 nanosheets was systematically studied. • V 2 O 5 nanosheets possess high electrochemical activity, cycling stability and rate capability. • The influence of the electrochemical reaction kinetics on the performance is discussed. [Display omitted] Large-area two-dimensional petal-like V 2 O 5 nanosheets present superior cycling stability and rate capability due to the increased electrode/electrolyte contact area, enhanced strain tolerability, shortened transport path for both Li ions and electrons, and significantly improved reaction kinetics. There is a need for simple and rapid methods of controllably fabricating large-area V 2 O 5 thin nanosheets for applications in high-energy Li-ion batteries (LIBs). Here, we report a novel growth-induced synthesis of two-dimensional (2D) petal-like V 2 O 5 nanosheets with a thickness of approximately 15 nm and lateral size exceeding 5 µm. The mechanism of formation of the nanosheets is systematically investigated by studying the effects of reagent concentrations on the nanosheet morphology. The resultant V 2 O 5 nanosheets were effective cathode materials for LIBs, giving high reversible capacities of 291.7 and 101 mAh g−1 at current densities of 0.1 and 3.0 A g−1, respectively, in the voltage window of 2.0–4.0 V. Furthermore, the cathode operated stably for 200 cycles at 1.5 A g−1, with a reversible capacity of 139.6 mAh g−1 at the 200th cycle, corresponding to a capacity fading of 0.03% per cycle. The enhanced lithium storage is attributed to the increased electrode/electrolyte contact area, the enhanced strain tolerability, and shortened charge transport path of the unique nanosheet structure. The influence of the electrochemical reaction kinetics on the performance is also discussed in detail. These findings will accelerate the development of V 2 O 5 cathodes for next generation high-energy LIBs. [ABSTRACT FROM AUTHOR]

Abstract: NaNiF3/Ni composite material is successfully synthesized by a novel electrochemical corrosion method. The morphology and size of the as-prepared composite material are studied by field emission scanning electron microscopy (FE-SEM). The results indicate that the NaNiF3 shows particle-like morphology with mean size about 3μm, which grows directly on the surface of Ni foam. Electrochemical properties of the NaNiF3/Ni as anode for lithium ion batteries are studied by conventional charge/discharge test, which show obvious voltage plateaus in charge/discharge curves, endowing it with potential application in lithium ion battery. [Copyright &y& Elsevier]