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Kinetic Monte Carlo simulations are applied to simulate the insertion of lithium ions into graphite. The present results show how the kinetics of lithium ion intercalation in graphite rules the global process, leading to metastable phases. The relatively slow rate of the events of insertion (deinsertion) of lithium ions into (from) graphite is found to yield the intercalation structures proposed by Daumas and Hérold. These arrangements can be considered as frustrated, metastable structures, with a higher energy than that of the equilibrium state. [ABSTRACT FROM AUTHOR]

The overwhelming advantage of Si nanoparticles (SiNPs) over Si microsized particles (SiMPs) as anode materials is compromised by their severe side reactions with electrolyte and agglomeration during cycling. Unlike usual solutions such as surface encapsulation or coating, here, a new strategy was proposed by mimicking the self-healing ability of living organisms. Ureidopyrimidinone functionalized polyethylene glycol (UPy-PEG-UPy) was successfully synthesized. Taking it as binder, SiNPs achieved excellent electrochemical performance with an initial coulombic efficiency (ICE) as high as 81% and a reversible capacity of 1454 mAh/g after 400 cycles corresponding to an average capacity decay of 0.04% per cycle. This achievement is attributed to the self-healing ability of UPy-PEG-UPy, which enables to spontaneously heal micro-cracks on electrode prior to its propagation, therefore preventing Si particles agglomeration and maintaining electrode integrity. [ABSTRACT FROM AUTHOR]

LiCoO 2 (LCO) has been functionally modified by mixed lithium ion and electron conducting LiAlPO 3.93 F 1.07 (LAPF) for the first time. Due to the unique coating layer with accepted Li-ion diffusion rate and electronic conductivity, the LAPF-coated LCO exhibits outstanding rate capability and cycle stability in the voltage range of 2.75–4.55 V. This material delivered a specific capacity of 206 mAh·g − 1 up to 0.5C rate and the capacity retention was 91.7% after 50 cycles, which is a remarkable improvement comparing with uncoated LCO (34.8%). It also exhibited superior rate capability with a discharge capacity of 161.4 mAh·g − 1 at 4C. The functionalized LAPF coating technique is an efficient approach to improve the electrochemical performance of LCO and can also be referred for other layered oxide cathode materials. [ABSTRACT FROM AUTHOR]

Changes in the concentration of ions in the electrolyte solution between electrodes in a lithium ion battery were studied by in situ multi-microprobe Raman spectroscopy. The distance between the two electrodes was set to 190 μm. Six separator films, each with a thickness of 25 μm, were inserted between the two electrodes, and probes were inserted between the separator films at the anode side, the middle position and the cathode side. After repeated charge/discharge cycles, the concentration of ions increased and decreased during charging and discharging, respectively. Such concentration changes first started to occur at the anode side and then occurred at the middle position and finally at the cathode side. The results suggest complexity of changes in the concentration of ions in separator films with micropores in practical batteries. [ABSTRACT FROM AUTHOR]

Si/C composites of carbon hollow structures loaded with Si nanoparticles (NPs) (Si/C-HSs) were prepared by one-step pyrolysis of a mixture of Si NPs and expandable microspheres (EMs). For the Si/C-HSs, hollow carbon shells with rough surfaces were formed by directly carbonizing the polymer shells of EMs, and the Si NPs fell into the void space or were loaded on the rough surfaces of the carbon shells. The EM-based carbon shells accommodated the volume expansion of the Si NPs and improved the electrical conductivity of the composites. As a result, the Si/C-HSs exhibited a high capacity (initial reversible capacity: 854.4 mAh g − 1 at 300 mA g − 1 ), stable cycling performance (capacity retention: 80% after 50 cycles), and excellent rate capability. [ABSTRACT FROM AUTHOR]

[Display omitted] • The impedances of two SiO x single particles at different conditions are measured. • The Li+ diffusivity and exchange current density of SiO x are obtained. • The fitting results are consistent with the previous research. • Kinetic properties can be included as a new evaluation index for materials. In this study, single-particle electrode technique is adopted to measure the impedance response of SiO x materials for the first time. The electrochemical impedance spectroscopies of two SiO x particles are measured at different insertion ratios and different temperatures. Two kinetic parameters, namely Li+ diffusivity and exchange current density, are obtained using our previously proposed impedance model which takes into account the stress effect on Li+ diffusion and surface reaction. The dependence of the two parameters on the Li+ insertion ratio and temperature is obtained. The fitted results are found to be strongly consistent with previous research. Lastly, through comparison with the results of earlier studies with the help of the single-particle electrode technique, we find that the kinetic performance of SiO x is much poorer than graphite, and smaller particles are recommended to use compared with graphite when applying SiO x as the anode material. The single-particle electrode can serve as an effective tool to evaluate the electrochemical kinetics of various materials and provides a new index for material evaluation. [ABSTRACT FROM AUTHOR]

Vanadium dioxide (VO 2 ) nano-sheets were directly synthesized via a continuous hydrothermal process and were investigated as electrodes in a wide potential range of 0.05–3 V vs. Li/Li + . The nano-sheets showed excellent capacity retention, with a specific capacity of 350 mAh g − 1 at an applied current of 0.1 A g − 1 and 95 mAh g − 1 at 10 A g − 1 . Further electrochemical testing suggested that a significant proportion of the charge storage in the cells was due to pseudocapacitive processes. [ABSTRACT FROM AUTHOR]

An approach is proposed to evaluate the VC effect in a LiFePO 4 /graphite cell at 60 °C through liquid chromatography mass spectrometry (LC-MS) together with direct analysis in real time mass spectrometry (DART-MS). The LC-MS result shows that VC can effectively suppress the formation of phosphate esters as well as carbonate oligomers during the electrochemical cycling. It is also known from DART-MS analysis that VC assists the formation of thermally resistant oligomeric phosphate ester layer on the graphite surface, storing more solvent EC inside the layer. On the other hand, no compounds are observed on the LiFePO 4 cathode surface. The formation of the denser oligomeric phosphate ester layer is found to be the reason for the improved cycle stability of the cell cycled at elevated temperature. [ABSTRACT FROM AUTHOR]

Abstract: We report a facile synthesis of nanostructured Cu-incorporated SnO2. Aggregates composed of uniform∼5nm-sized nanoparticles were obtained through a simple room-temperature reaction between CuO and SnC2O4 in aqueous solution. The material is single-phase with copper incorporated mainly as Cu+. The synthesis approach also allows mixing with CuO to prepare SnO2/CuO nanocomposites. The synthesized materials show an improved cycle performance as anode materials in lithium ion batteries due to an improved morphology and in situ formation of metallic copper upon cycling (in the voltage range 0.05–1.1V vs. Li/Li+). [Copyright &y& Elsevier]

Abstract: We present an anode material consisting of Ge–Cu nanoparticles (Ge–Cu NPs) which were fabricated by a one-step inert gas condensation method. The Ge–Cu NPs consisting of amorphous Ge and orthorhombic Cu3Ge phase were found to have good performance during the lithiation/delithiation process. Reversible discharge capacities were determined of 843, 773, 680, 516 mAh g−1 at 0.2, 0.5, 1 and 2 C, respectively, with a Coulombic efficiency higher than 96%. [Copyright &y& Elsevier]

Abstract: A LiCoPO4/Li4Ti5O12 battery prototype is designed to fully take profit of high energy density of LiCoPO4 and superior reliability of Li4Ti5O12. Electrochemical test results show that the battery affords an operational voltage of 3.2V and delivers a reversible capacity of 122mAhg−1. Based on the mass of LiCoPO4, the energy density of such a battery can reach 378mWhg−1. Provided the long-term cyclability of the LiCoPO4 cathode could be well addressed, this LiCoPO4/Li4Ti5O12 system offers an alternative for large-scale energy storage application. [Copyright &y& Elsevier]

Abstract: We report a simple process to coat silicon monoxide (SiO) particles with nitrogen-doped carbon layers (NC-SiO) by using a nitrogen-containing ionic liquid. The nitrogen-doping addresses the moderate electric conductivity of SiO particles as large as 20μm and thus enables NC-SiO to exhibit substantially improved specific capacity and rate performance as compared to those of bare carbon-coated SiO (C-SiO) and bare SiO counterparts. Due to the simplicity of the coating procedure, the current approach should be readily applicable to other lithium battery electrodes that suffer from low electronic conductivities. [Copyright &y& Elsevier]

Abstract: In this work, we proposed a new solution to the instability of LiNi0.5Mn1.5O4 cathode for lithium ion battery by simply controlling discharge end-off voltage. The morphology and the crystal structure of LiNi0.5Mn1.5O4 before and after cycling at elevated temperature were characterized with XRD and SEM, and its performances as cathode of lithium ion battery were investigated by cyclic voltammetry and galvanostatic charge–discharge tests. It is found that the cyclic stability of LiNi0.5Mn1.5O4 at elevated temperature is significantly improved by changing the end-off discharge voltage from 3.5V to 4.0V (vs. Li+/Li). After 500cycles with 1C rate at 55°C, the capacity retention rate of LiNi0.5Mn1.5O4 is only 16.8% for the end-off discharge voltage of 3.5V, but improves to 84.9% for 4.0V. The improved stability is attributed to the limitation of the reduction of Mn4+ to Mn3+ that causes the primary particle separation of LiNi0.5Mn1.5O4. [Copyright &y& Elsevier]

Abstract: Carbon nanotube (CNT) wired LiCo0.5Mn0.5PO4 nanocomposites were readily prepared using a facile one-pot hydrothermal approach. The prepared LiCo0.5Mn0.5PO4-CNT is composed of uniform nanoparticles of LiCo0.5Mn0.5PO4 intimately interconnected by CNT networks. The electrochemical test results show that the CNT networks play a critical role in maintaining electrical conduction and in ensuring electrode stability of LiCo0.5Mn0.5PO4-CNT upon cycling, thus leading to much enhanced electrochemical properties compared with neat LiCo0.5Mn0.5PO4. It is found that the LiCo0.5Mn0.5PO4-CNT composite exhibits a high capacity up to 151mAhg−1 and an energy density of 620mWhg−1, and maintain 92% of the initial capacity after 30 charge/discharge cycles, thereby indicating its potential for energy storage and conversion application. [Copyright &y& Elsevier]

Abstract: As an anode material for lithium-ion batteries (LIBs), silicon offers among the highest theoretical storage capacity, but is known to suffer from large structural changes and capacity fading during electrochemical cycling. Nanocomposites of silicon with carbon provide a potential material platform for resolving this problem. We report a spray-pyrolysis approach for synthesizing amorphous silicon–carbon nanocomposites from organic silane precursors. Elemental mapping shows that the amorphous silicon is uniformly dispersed in the carbon matrix. When evaluated as anode materials in LIBs, the materials exhibit highly, stable performance and excellent Coulombic efficiency for more than 150 charge discharge cycles at a charging rate of 1A/g. Post-mortem analysis indicates that the structure of the Si–C composite is retained after extended electrochemical cycling, confirming the hypothesis that better mechanical buffering is obtained when amorphous Si is embedded in a carbon matrix. [Copyright &y& Elsevier]

Abstract: Promising capacity retention (more than 92% of initial capacity after 100cycles), was exhibited in cells (graphite/xLi2MnO3·yLiMO2) with 2wt.% LiDFOB as additive. The outstanding cell performance was associated with the formation of stable solid electrolyte interface (SEI) film on the surface of electrodes derived from LiDFOB. Compared to the effect of the LiBOB additive, the main reason responsible for the greatly improved durability in LiDFOB added cells might be attributed to the more stable SEI film with lower interfacial resistance on the surface of anode. [Copyright &y& Elsevier]

Abstract: We report a silicon/graphene-sheet hybrid film prepared by combining electrophoretic deposition and radiofrequency magnetron deposition methods. The constructed hybrid film shows rough morphology with wrinkles and scrolling edges. As anode material for lithium ion batteries, the silicon/graphene-sheet hybrid film exhibits enhanced electrochemical performances with weaker polarization, higher capacity, better rate capability and cycling performance as compared to the bare silicon film. The silicon/graphene-sheet hybrid film delivers a high initial reversible capacity of 2204mAhg−1 and quite good cycling life (capacity maintenance is 87.7%) after 150cycles. The graphene-sheet in the hybrid film is responsible for the improvement of the electrochemical properties. The introduction of the graphene-sheet film not only enhances the adhesion between silicon and the current collector, but also alleviates the structure degradation caused by volume expansion and the shrinkage of silicon film during lithium-ion insertion/extraction, resulting in improved electrochemical performances. [Copyright &y& Elsevier]

Abstract: We report on a facile strategy for the direct and uniform deposition of a graphene/Co3O4 thin film onto stainless steel substrate (SS) through cathodic deposition. Graphene oxides (GOs) were treated with poly(ethyleneimine) (PEI) which acted as a stabilizer and binder between GOs and cationic metal precursor. For the formation of PEI‐modified GOs (PEI-GOs) and Co2+ complexes, the PEI-GOs dispersion was mixed with aqueous phase of Co(NO3)2, then, the solution was used as the plating bath for coelectrodeposition. Results showed that the PEI-GOs and cobalt oxides were uniformly distributed on the surface of SS evidenced by field emission scanning electron microscopy. The prepared graphene/Co3O4 film was employed as an anode material for lithium ion batteries, and it exhibited not only an enhanced cycleability but also high electronic conductivity. [Copyright &y& Elsevier]

Abstract: A novel C/Co composite with Co nanoparticles embedded in carbon matrix is synthesized firstly by pyrolysis of polymeric cobalt phthalocyanine (PcCo) at 700°C in argon atmosphere. This composite is investigated as an anode material for lithium ion batteries, indicating high tap density and excellent electrochemical performance. The C/Co electrode can retain a higher reversible capacity of over 600mAhg−1 at a current of 50mAg−1 after 40cycles and shows better rate capability and less hysteresis in comparison to carbon not containing Co. The significant improvement is attributed to the Co nanoparticles grown in-situ reaction with catalytic activity and high electrical conductivity. [Copyright &y& Elsevier]

Abstract: In this paper, we reported a novel solid electrolyte interphase (SEI) formation additive, prop-1-ene-1,3-sultone (PES), used in propylene carbonate (PC)-based electrolyte for lithium ion batteries. The effect of PES on the co-intercalation of PC into anode and the battery performance was investigated by energy calculation, cyclic voltammetry and battery charge–discharge test. The theoretical calculations and the voltammograms show that PES can be reduced prior to propane sultone (PS), a practical SEI formation additive for lithium ion batteries. Charge–discharge test shows that the use of PES can suppress successfully the co-intercalation of PC with lithium ions into graphite and the LiCoO2/graphite battery using PES exhibits better performance than that using PS as the SEI formation additive. [Copyright &y& Elsevier]

Abstract: Tetraethylene glycol dimethylether-lithium bis(oxalate)borate (TEGDME-LiBOB) electrolyte is here studied. Electrochemical impedance spectroscopy (EIS) measurements demonstrate that the electrolyte has conductivity higher than 10−3 S cm−1 at room temperature and about 10−2 S cm−1 at 60°C, while thermogravimetry indicates a stability extending up to 180°C. Sweep voltammetry of the electrolyte shows anodic stability extending over 4.6V vs. Li and cathodic peak at about 1.5V vs. Li/Li+, caused by a decomposition of LiBOB salt, and following prevented by using a pre-treated Sn-C anode. Furthermore, LiFePO4 electrode is successfully used as cathode in a lithium cell using the TEGDME-LiBOB electrolyte. The promising electrochemical results, the low cost and the very high safety level candidate the electrolyte here reported as a valid alternative to the conventional electrolyte based on fluorinated salts presently used in the lithium ion battery field. [Copyright &y& Elsevier]

Abstract: A unique ordered mesoporous Sn–C composite with Sn nanoparticles confined in carbon nanorods was prepared using SBA-15 as the template. This composite was employed as the anode material of Li-ion batteries, delivering excellent electrochemical properties of high reversible lithium storage capacity (554 mAh g−1 after 200 cycles) and great rate capability (as high as 5000mA g−1). [Copyright &y& Elsevier]

Abstract: In this paper, we demonstrated that the high rate capability of electrode can be achieved by engineering the existing electrode materials. A simple approach has been developed to align the graphene nanosheet vertically on current collector, which not only facilitates both lithium ion and electron transport, but also simplifies the electrode fabrication without involving binder and conductive additives. The charging rate for the optimized electrode structure can be significantly increased while the graphitic feature of the electrode still retains. We envision the use of this highly stable structure as an integral addition to high capacity anode materials for lithium ion batteries of high power and energy density. [Copyright &y& Elsevier]

Abstract: The nano-silicon connected by a nest-like polyaniline (PANi) was simply synthesized by a chemical polymerization process. The cycle stability and rate performance of the Si/PANi composite were greatly enhanced compared with the pristine nano-silicon. The improved electrochemical characteristics are attributed to the volume buffering effect as well as effective electronic conductivity of the nest-like polyaniline, and lower aggregation of the nano-silicon. [ABSTRACT FROM AUTHOR]

Abstract: A lithium-organic coordination compound based on an aromatic carbonyl derivative, [Li2(C14H6O4)], was synthesized by the dehydration of [Li2(C14H6O4)·H2O], and used as a novel lithium-inserted material for lithium ion batteries. The synthesized material has initial discharge capacity of 126 and 115mAh/g at current densities of 22 and 111mAh/g, corresponding to the columbic efficiency of 99.2% and 98.3% at the first cycle, and its capacity fading is only 5% and 13% after 50 cycles, respectively, showing that this compound is a promising candidate as lithium-inserted material for lithium ion batteries. [ABSTRACT FROM AUTHOR]

Abstract: CuO/MWCNT nanocomposite is prepared by a simple precipitation method. The MWCNTs are incorporated into the leaf-like CuO nanoplates and build up a network to connect the CuO nanoleaves. The as-prepared CuO/MWCNT exhibits superior reversible Li-ion storage, the capacity maintains 627mAhg−1 at 60mAg−1 even after 50cycles. The improved capability is ascribed to the MWCNT network in the composite, which improves the electrical contact of CuO/CuO and CuO/current collector, facilitates the charge transfer on CuO/electrolyte interfaces, and compensates the volume change of CuO during cycling. [Copyright &y& Elsevier]

Abstract: Hierarchically ordered porous nickel oxide array film was prepared by electrodeposition through monolayer polystyrene spheres template. The as-prepared film had a highly porous structure of interconnected macrobowls array possessing nanopores. As anode material for lithium ion batteries, the porous array NiO film exhibited weaker polarization, higher coulombic efficiency and better cycling performance in comparison with the dense NiO film. After 50cycles, the discharge capacity of porous array NiO film was 518mAhg−1 at 1C rate, higher than that of the dense NiO film (287mAhg−1). The enhancement of the electrochemical properties was due to the unique hierarchical porous architecture, which provided fast ion/electron transfer and alleviated the structure degradation during the cycling process. [Copyright &y& Elsevier]

Abstract: Hollow microspheres composed of phase-pure ZnFe2O4 nanoparticles (hierarchically structured) have been prepared by hydrothermal reaction. The unique hollow spherical structure significantly increases the specific capacity and improves capacity retention of this material. The product of each phase transition during initial discharge (ZnFe2O4 ↔Li0.5ZnFe2O4 ↔Li2ZnFe2O4 →Li2O+Li–Zn+Fe) and their structural reversibility are recognized by X-ray diffraction and electrochemical characterization. The products of the deeply discharged (Li–Zn alloy and Fe) and recharged materials (Fe2O3) were clarified based on high resolution transmission electron microscopic technique and first-principle calculations. [Copyright &y& Elsevier]

Abstract: Mesoporous Ge was prepared by mechanochemical reaction of GeO2 and Mg powders followed by an etching process with HCl solution. It was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and charge–discharge measurement. With a pore-distribution concentrated around 10nm, the product presents a BET surface area of 49.98m2/g. When using as an anode material for lithium ion battery, the mesoporous Ge exhibits a reversible capacity of 950mAh/g and retains a capacity of 789mAh/g after 20 cycles at a current density of 150mA/g. The cycleability is significantly improved compared with non-porous Ge. [Copyright &y& Elsevier]

Abstract: Uniform α-Fe2O3 nanocapsules with a high surface area were synthesized by a novel wrap–bake–peel approach consisting of silica coating, heat treatment and finally the removal of the silica coating layer. The length, diameter and shell thickness of the hematite nanocapsules were about 65, 15 and 5nm, respectively. The electrochemical properties of the α-Fe2O3 nanocapsules were investigated by cyclic voltammetry and charge/discharge measurements. The α-Fe2O3 nanocapsules showed a high reversible capacity of 888mAh/g in the initial cycle and 740mAh/g after 30 cycles as well as good capacity retention. This excellent electrochemical performance was attributed to the high surface area, thin shell and volume space of the hollow structure. [Copyright &y& Elsevier]

Abstract: This paper reports the microwave-assisted synthesis of Co3O4 nanomaterials with different morphologies including nanoparticles, rod-like nanoclusters and macroporous platelets. The new macroporous platelet-like Co3O4 morphology was found to be the best suitable for reversible lithium storage properties. It displayed superior cycling performances than nanoparticles and rod-like nanoclusters. More interestingly, excellent high rate capabilities (811mAhg−1 at 1780mAg−1 and 746mAhg−1 at 4450mAg−1) were observed for macroporous Co3O4 platelet. The good electrochemical performance could be attributed to the unique macroporous platelet structure of Co3O4 materials. [Copyright &y& Elsevier]

Abstract: Solid state and interfacial processes are not necessarily the principal rate limiting process during fast discharge of LiFePO4 composite electrodes with particle size less than 1μm. A simple model based on salt diffusion to a sharp discharge front explains the observed dependence of discharge rate on electrode thickness, electrolyte concentration, lithium transference number, and dilution of the active material. The effect of changing the electrolyte is dramatic, e.g. discharge to 25% capacity was obtained on a 40μm thick electrode after only 4s in an optimised electrolyte, aqueous Li2SO4, showing a rate of 900C as compared with less than 10C for a similar cell with an ionic liquid as the electrolyte. [Copyright &y& Elsevier]

Abstract: Li[Li0.23Co0.3Mn0.47]O2 cathode material was prepared by a sol–gel method. The material had a primary particle size of about 100nm, covered by a 30Å of Li2CO3 layer. The material showed promising electrochemical performance when cycled up to 3C rate. The electrochemical kinetics of the first charge was much slower than that of the second charge, due to the complex electrochemical process which involved not only Li+ diffusion but also release of oxygen. By taking account of this, the material was pre-charged very slowly (∼C/50) in the first cycle. This led to excellent electrochemical performance in the following cycles. For instance, the 1C-rate capacity increased to 168mAhg−1 after 50 cycles, comparing with the 145mAhg−1 obtained without pre-charging. [Copyright &y& Elsevier]

Abstract: The sodium lithium titanate with composition Na2Li2Ti6O14 has been synthesized by a sol–gel method. Thermogravimetric analysis and differential thermal analysis (TG–DTA) of the thermal decomposition process of the precursor and X-ray diffraction (XRD) data indicate the crystallization of sodium lithium titanate has occurred at about 600°C. Electrochemical lithium insertion into Na2Li2Ti6O14 for lithium ion battery has been investigated for the first time. These results indicate the discharge and charge potential plateaus are about 1.3V. The initial discharge capacity is much higher than the charge capacity and irreversible capacity exists in the voltage window 1–3V. Subsequently, the discharge capacity decreases slowly, but the charge capacity increases slightly in the following cycles. After a few cycles, the specific capacity remains almost constant values and the sample exhibits the excellent retention of capacity on cycling. [Copyright &y& Elsevier]

Abstract: In this paper, we report a new flame retardant, vinyl-Tris-(methoxydiethoxy)silane (VTMS), for use in electrolytes of lithium ion batteries. Burning tests showed that the addition of VTMS at 5–15vol.% into the currently used electrolyte could effectively reduce the flammability. As long as the added amount was below 10%, electrochemical performance such as reversible capacity and cycling showed little change. In addition, differential scanning calorimetry (DSC) in combination with X-ray photoelectron spectroscopy (XPS) disclosed that VTMS participated in the formation of the surface film on the cathode, which played a pivotal role in markedly improving the thermal stability of the LiCoO2 cathode. This kind of ecofriendly compound provides a new promising direction for the development of organic additives to improve the safety of lithium ion batteries. [Copyright &y& Elsevier]

Abstract: Core-shell Cu2O/Cu composites were successfully prepared by over-reduction of aqueous CuSO4 with hydrazine hydrate as reductant. Field emission scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM) clearly illuminate that the core is Cu2O with 400nm in diameter, and the shell is Cu with about 50nm in thickness. The core-shell Cu2O/Cu exhibited weaker polarization and higher coulombic efficiency than pure octahedral Cu2O, especially in the initial stage of cycles. After 50 cycles, the reversible capacity of Cu2O/Cu (360mAhg−1) was much higher than that of pure Cu2O (160mAhg−1). The improvement of electrochemical properties is attributed to the core-shell structure of Cu2O/Cu and the catalytic effect of Cu on the decomposition of Li2O during the charging process. [Copyright &y& Elsevier]

Abstract: In this paper, flower-like spinel Li4Ti5O12 consisting of nanosheets was synthesized by a hydrothermal process in glycol solution and following calcination. The as-prepared product was characterized by scanning electron microscopy, transmission electron microscopy, X-ray powder diffraction and cyclic voltammetry. The capacity of the sample used as anode material for lithium ion battery was measured. This structured Li4Ti5O12 exhibited a high reversible capacity and an excellent rate capability of 165.8mAhg−1 at 8C, indicating potential application for lithium ion batteries with high rate performance and high capacity. [Copyright &y& Elsevier]

Abstract: A facile method has been developed to synthesize Al2O3-coated LiNi0.8Co0.2O2 cathode materials. The sample was characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM) and energy dispersive analysis of X-rays (EDAX). Electrochemical tests show that the cycling stability of LiNi0.8Co0.2O2 at room temperature is effectively improved by Al2O3 coating. The differential scanning calorimetry (DSC) and high temperature (60°C) cycling tests indicate that Al2O3 coating can also improve the thermal stability of LiNi0.8Co0.2O2, which is attributed to that the coating layer can protect the LiNi0.8Co0.2O2 particles from reacting with the electrolyte. [Copyright &y& Elsevier]

Abstract: Commercial LiCoO2 has been modified with MnSiO4 as a novel coating material. The structures, morphologies, overcharge behaviors and thermal stabilities of the pristine and MnSiO4-coated LiCoO2 materials were studied. The MnSiO4-coated LiCoO2 had initial discharge specific capacities of 181.1 and 232.2mAhg−1 within the potential ranges 2.75–4.5 and 2.75–4.7V (vs. Li+/Li), respectively. It was found that the overcharge tolerance of the coated cathode was significantly better than that of the pristine LiCoO2 under the same conditions – the discharge specific capacities of the coated cathode at upper charge cutoff voltages of 4.5 and 4.7V were as high as 168.7 and 154.3mAhg−1, respectively, after 50 cycles. Moreover, DSC showed that the coated LiCoO2 had a higher thermal stability than the pristine LiCoO2. [Copyright &y& Elsevier]

Abstract: Tremella-like structured MoO2 consisting of nanosheets was obtained via a Fe2O3-assisted hydrothermal reduction of MoO3 in ethylenediamine aqueous solution. The as-prepared product was characterized and tested with scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV) and capacity measurement as anode material for lithium ion batteries. This structured MoO2 shows very high reversible capacity (>600mAhg−1), good rate capability and cycling performance, presenting potential application as anode material for lithium ion batteries with high rate capability and high capacity. [Copyright &y& Elsevier]

Abstract: NiO, Li0.68Ni1.32O2 and Li0.68Ni1.32O2/Ag composite as anodes for Li-ion batteries are reported. Li0.68Ni1.32O2 decomposed to Ni and Li2O when discharged to 0.02V, according to XRD analysis, which was similar to NiO. Increased initial coulombic efficiency was obtained for the Li0.68Ni1.32O2 electrode (73%), higher than that of NiO (64.9%), but its cycling performance became worse because poorer conductive Li2O formed when the first discharge process was finished. However, the Li0.68Ni1.32O2/Ag electrode exhibited better cycling performance than NiO and Li0.68Ni1.32O2, because the Ag nanoparticles in the composite improved the conductivity of the electrode. The initial coulombic efficiency for Li0.68Ni1.32O2/Ag is still as high as 72%, nearly the same as that of Li0.68Ni1.32O2. [Copyright &y& Elsevier]

Abstract: Nano-sized nickel ferrite (NiFe2O4) was prepared by hydrothermal method at low temperature. The crystalline phase, morphology and specific surface area (BET) of the resultant samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and nitrogen physical adsorption, respectively. The particle sizes of the resulting NiFe2O4 samples were in the range of 5–15nm. The electrochemical performance of NiFe2O4 nanoparticles as the anodic material in lithium ion batteries was tested. It was found that the first discharge capacity of the anode made from NiFe2O4 nanoparticles could reach a very high value of 1314mAhg−1, while the discharge capacity decreased to 790.8mAhg−1 and 709.0mAhg−1 at a current density of 0.2mAcm−2 after 2 and 3 cycles, respectively. The BET surface area is up to 111.4m2 g−1. The reaction mechanism between lithium and nickel ferrite was also discussed based on the results of cycle voltammetry (CV) experiments. [Copyright &y& Elsevier]

Abstract: Three-dimensionally (3D) ordered mesoporous titania (anatase) microparticles without substrate were prepared by using polystyrene (PS) colloidal crystal as a template and characterized by transmission electron microscopy, X-ray diffraction, thermogravimetry and electrochemical measurement. As anode materials for lithium ion battery, they present eximious kinetic performance and good capacity retention due to their special architecture with mesoporous channels and thin walls, which are beneficial to the diffusion of lithium ions. Besides, mixing 3D ordered mesoporous titania microparticles with conductive additive can reduce the resistance of the anode, favor the mobility of the electrons, and decrease the polarization. [Copyright &y& Elsevier]

Abstract: A novel kind of sandwiched polymer membrane was prepared by coating three layers of poly(vinyl difluoride) (PVDF), poly(methyl methacrylate) (PMMA) and PVDF, separately. Its characteristics were investigated by scanning electron microscopy, FT-IR, X-ray diffraction, and differential thermal analysis. It consists of two phases. The outer PVDF layers are porous, and the inner PMMA layer is solid. Since the PMMA has a good compatibility with the carbonate-based liquid electrolyte, the membrane can easily absorb the electrolyte to form a gelled polymer electrolyte (GPE). As a result, the evaporation peak of the liquid electrolyte is increased to 160°C. Due to very low evaporation of the liquid electrolyte, LiCoO2 shows good cycling behavior in the range of 4.4–3.0V when this GPE is used as the separator and polymer electrolyte, and lithium as the counter and reference electrode. This unique sandwiched membrane is promising for application in scale-up lithium ion batteries with high safety and high energy density. [Copyright &y& Elsevier]

Abstract: We demonstrated a simple approach for the synthesis of a kind of novel porous anatase TiO2 nanorods. The method is based on a reaction in composite-hydroxide eutectic system and normal atmosphere without using an organic dispersant or capping agent. The synthesis technique is cost effective, easy to control and is adaptable to mass production. This is the first time TiO2 nanorods with a porous structure are fabricated by using this method. The as-prepared material was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), nitrogen adsorption and desorption experiments and electrochemical measurements. The results showed that the anatase TiO2 nanorods obtained in our experiment have a large specific surface area with a porous structure which makes it have a potential application in catalysts and battery materials, especially in lithium ion batteries. In this study, we mainly tested their electrochemical performance as negative materials for lithium ion batteries. Further research to optimize synthesis conditions, particularly to develop their application in the field of catalysis is currently in progress. [Copyright &y& Elsevier]

Abstract: Using a commercially available LiCoO2 as starting material, a surface-modified cathode material was obtained by coating it with a nano layer of amorphous carbon. The carbon-coated LiCoO2 was characterized by X-ray diffraction analysis, scanning electronic microscopy, transmission electronic microscopy, electrochemical impedance spectroscopy and measurement of charge/discharge behavior. Results show that the carbon-coated LiCoO2 displays marked lower charge transfer resistance, higher lithium ion diffusion coefficient and much better rate capability than the original LiCoO2. It also indicates promising application of lithium ion batteries in the areas requiring charge and discharge at high rate. [Copyright &y& Elsevier]

Abstract: Net-structured NiO was prepared by urea-mediated homogeneous hydrolysis of Ni(CH3COO)2 under microwave radiation followed by a calcination at 500°C. NiO–C nanocomposite was prepared by dispersing the as-prepared net-structured NiO in glucose solution and subsequent carbonization under hydrothermal conditions at 180°C. The carbon in the composite was amorphous by the X-ray diffraction (XRD) analysis, and its content was 15.05wt% calculated according to the energy dispersive X-ray spectroscopy (EDX) result. Transmission electron microscopy (TEM) image of the NiO–C nanocomposite showed that the NiO network was homogeneously filled by amorphous carbon. The reversible capacity of NiO–C nanocomposite after 40 cycles is 429mAhg−1, much higher than that of NiO (178mAhg−1). These improvements are attributed to the carbon, which can enhance the conductivity of NiO, suppress the aggregation of active particles, and increase their structure stability during cycling. [Copyright &y& Elsevier]

Abstract: A three-dimensional cellular silicon-based anode was prepared by casting milled silicon powders into the “valley-ridge” copper architecture, then its electrochemical property and failure mechanism were studied by means of charging–discharging (C–D) test, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). In comparison with common 2D anode fabricated by “slurry-coating” technology on flat copper foil, the 3D copper framework has shown a great structure advantage in restricting severe volume changes of silicon particles. This “stress-alleviated” action can effectively impede strain-induced loosening happened inside electrodes during charging and discharging, and consequently improve cycle-life and coulombic efficiency of silicon-based anode. [Copyright &y& Elsevier]

Abstract: The Si/SiO nanocomposite was synthesized by a sol–gel method in combination with a following heat-treatment process. It was analyzed by X-ray diffraction (XRD), transmission electron microscopy (TEM), cyclic voltammetry (CV) and capacity measurement as anode material for lithium ion battery. Si nanoparticles were coated with SiO and a core-shell structured nanocomposite was formed. The core-shell Si/SiO nanocomposite displays better reversibility of lithium insertion/extraction and higher coulomb efficiency than virginal Si nanoparticles. The SiO shell envelops the Si nanoparticles to suppress the aggregation of the nanoparticles during cycling. As a result, the core-shell Si/SiO nanocomposite exhibits better capacity retention than virginal Si nanoparticles, indicating that this is a promising approach to improve the electrochemical performance of nano anode materials for lithium ion battery. [Copyright &y& Elsevier]

Abstract: A novel method (a rheological phase reaction) was used to synthesize WS2 nanoflakes by adding oxalic acid as a reducing reagent. High resolution electron microscopy observations revealed that the as-prepared WS2 nanoflakes had started to curve and that WS2 nanotubes were partly formed. The lithium intercalation/deintercalation behavior of as-prepared WS2 electrode was also investigated. It was found that the WS2 nanoflake electrode exhibited higher specific capacity with very good cycling stability compared to WS2 nanotube or nanoparticle electrodes. The reasons for the improved electrochemical performance of the nanoflake electrodes are also discussed. [Copyright &y& Elsevier]