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Phase pure lithium trivanadate (LiV3O8) was synthesized by an ultrasound-assisted rheological phase reaction method for aqueous supercapacitor applications. The precursor was exposed to ultrasound for different time periods of 2, 6 and 10 h and then calcined under similar conditions. The effects of ultrasound on the structural features of the synthesized samples was characterized by XRD, and FTIR spectroscopy and the morphological features by SEM analysis. The sample synthesized by exposing the precursor to ultrasound for 10 h showed a high value of d100spacing, which facilitated the lithium (Li+) ion movement. Also, the formation of rod-like structures by the exposure of ultrasound facilitated the fast Li+ ion movement and enhanced the electrochemical performance. The electrochemical performance was measured using a three-electrode cell setup in the potential range of −0.8 to 0.2 V using 1 M LiNO3aqueous electrolyte. The specific capacitance of the material was found to be 120 F/g at a current density of 1A/g for the sample sonicated for 10 h (10S-LVO). The symmetric supercapacitor constructed using 10S-LVO showed the highest specific capacitance of 317F/g at 0.5 A/g, with 66.28% capacitance retention at 1A/g after 150 cycles. Effect of ultrasound on the morphology of LiV3O8 [ABSTRACT FROM AUTHOR]

LiV3O8 with nanorod structure was prepared by hydrothermal-solid method. In this work, the structure and morphology of LiV3O8 were characterized by XRD, FTIR, SEM, XPS, etc., and the electrochemically switched ion exchange (ESIX) performance of LiV3O8 synthesized at different calcination temperatures was investigated. The experiment results show that LiV3O8 calcined at 500 ℃ had evenly nanorod morphological structure and the best electrochemical performance. The lithium ion adsorption capacity of LiV3O8 film reached 36.36 mg/g at 100 mg/L Li+ solution by ESIX technology. Moreover, LiV3O8 exhibited high selectivity and stability towards Li+. The selectivity factors of Li+/K+ and Li+/Mg2+ reached 38.43 and 4.75, respectively, when the initial molar ratios of Li+/K+/Mg2+ is 1∶1∶1. The lithium ion adsorption capacity of LiV3O8 film still maintained 98.3% of the initial value after 5 cycles.

Although research on the preparation of metal oxides and other materials for various applications increases exponentially, it is more important to understand the need for eco-friendly methods of preparation to preserve the environment. Most of the methods available today are expensive, environmentally harmful, and inefficient with respect to mass production. The present review has explored the Rheological Phase Reaction (RPR) method, which has been extensively utilized as an eco-friendly industrial method for the preparation of metal oxides and metal oxide/carbon composite for lithium ion battery applications. Based on the literature reports, this review has two motivations: to identify the Rheological Phase Reaction (RPR) as the mass production method for preparing metal oxides, metal oxide/carbon composites, and other materials for different applications, to discuss the preparation steps involved, its advantages, the drawbacks associated; and to give a detailed review of the electrochemical performance of different metal oxides by the RPR method for application on the lithium ion battery, with particular emphasis on lithium trivanadate (LiV3O8). [ABSTRACT FROM AUTHOR]

Although research on the preparation of metal oxides and other materials for various applications increases exponentially, it is more important to understand the need for eco-friendly methods of preparation to preserve the environment. Most of the methods available today are expensive, environmentally harmful, and inefficient with respect to mass production. The present review has explored the Rheological Phase Reaction (RPR) method, which has been extensively utilized as an eco-friendly industrial method for the preparation of metal oxides and metal oxide/carbon composite for lithium ion battery applications. Based on the literature reports, this review has two motivations: to identify the Rheological Phase Reaction (RPR) as the mass production method for preparing metal oxides, metal oxide/carbon composites, and other materials for different applications, to discuss the preparation steps involved, its advantages, the drawbacks associated; and to give a detailed review of the electrochemical performance of different metal oxides by the RPR method for application on the lithium ion battery, with particular emphasis on lithium trivanadate (LiV3O8).

Layered nanosheets of a LiV3O8 cathode material were successfully prepared via a modified solid-state synthesis. The morphological changes of the layered nanosheets of the LiV3O8 cathode, which resulted from preparation at different temperatures, strongly affected the electrochemical performance of this cathode material. The layered nanosheets of the LiV3O8 cathode prepared at 500 °C delivered the highest electrochemical performance with initial charge and discharge capacities of 212 and 175 mAh g−1, respectively, when cycled between 1.5 and 4.0 V versus Li/Li+. The particulate morphology of LiV3O8 showed widths in a range of 100-145 nm and lengths between 1.0 and 2.5 µm. The layered nanosheet structure contributed to the increased electrochemical performance of LiV3O8 as a cathode material for applications in high-energy lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Aqueous zinc-ion batteries (AZIBs) are promising candidates for large-scale energy storage because of their low cost and high safety. However, their practical applications are impeded by low energy density and short service life. Here, an aqueous Zn2+/Li+ hybrid-ion battery is fabricated using the LiV3O8 nanorods as the cathode, metallic Zn as the anode, and 3 M Zn(OTf)2 + 0.5 M LiOTf aqueous solution as the electrolyte. Compared with the batteries using pure 3 M Zn(OTf)2 electrolyte, the cycle performance of the hybrid-ion battery is significantly improved. After 4000 cycles at 5 A g1, the remaining capacity is 163.9 mA h g−1 with impressive capacity retention of 87.0%. Ex-situ XRD, ex-situ XPS, and SEM tests demonstrate that the hybrid electrolyte can inhibit the formation of the irreversible Zn3(OH)2V2O7·2H2O by-product and restrict Zn dendrite growth during cycling, thereby improving the cycle performance of the batteries.

To improve the stability and performance of the cathode materials, an ionic conductor layer was coated successfully on the surface of Li1.2Mn0.54Ni0.13Co0.13O2 (LMNC) microspheres. The structural analysis confirmed that LiV3O8 coating did not change the basic structure of LMNC, and all obtained materials are solid solutions with a good-layered structure and a good crystallinity. The microscopy measurement showed that the thickness of the coating layer for the LV-3 sample is about 2.5 nm. This appropriate layer is helpful for improving the surface stability of LMNC and the diffusion of lithium, leading to an obvious enhancement of the electrochemical performance. Our result confirmed that the average discharge specific capacities for LV-3 sample at 0.1 C, 0.2 C, 0.5 C, 1 C, and 3 C are respectively 265.9, 219.1, 188.0, 156.3, and 121.5 mAh g−1, which are much larger than the values of other samples. After 50 cycles at a 1 C rate, the capacity retentions for different samples are 60.7%, 74.0%, 87.6%, and 70.4%, indicating that LV-3 sample exhibits the best performance. Furthermore, EIS measurements showed that the diffusion coefficient for LV-3 sample is calculated to be 1.26 × 10−15 cm2 s−1, which is also the largest value among all considered samples. Our experiments identified that coating an ionic conductive layer on the cathode material surface will significantly improve their rate capacity and cycling stability. [ABSTRACT FROM AUTHOR]

A versatile synthetic approach is demonstrated to fabricate vanadium pentoxide hierarchical structures with three-dimensional electron carriers as anode materials for lithium-ion battery. Such unique structures are favorable for providing easy access of electrolyte to the electrode during lithiation-delithiation process and also shortening the pathway of the ion and electron transport, which guarantee excellent electrochemical performance. As a consequence, high specific capacities of 960 mAh g−1 at 200 mA g−1 and 738 mAh g−1 at 500 mA g−1 after 300 cycles are achieved without obvious decay. More remarkably, it is essential to rebuild a new recycling process owing to the massive waste produced by dealing with spent lithium-ion battery. Therefore, an energy-saving and environment-friendly process is introduced to recycle the used V 2 O 5 batteries. Through a facile annealing process, LiV 3 O 8 is obtained and reused as sustainable anode materials for the first time. The recycled product LiV 3 O 8 delivers excellent electrochemical performance, e.g., a high capacity of 542 mAh g−1 at 200 mA g−1 and the coulombic efficiency of over 99% after 600 cycles. This finding not only promotes the development of vanadium oxides for lithium-ion battery, but also sheds light on searching potential protocol for metal ion battery recycling. Image 1 • Hydrated V 2 O 5 nanoribbons entangled with GO nanosheets was fabricated. • Hierarchical V 2 O 5 ·nH 2 O@GO exhibits excellent lithium storage performance. • An energy-saving process was introduced to recycle the spent LIBs. • The recycled product delivers 542 mAh g−1 after 600 cycles at 200 mA g−1. [ABSTRACT FROM AUTHOR]

Lithium trivanadate (LiV 3 O 8) thin films were prepared by polymer assisted spin coating method. Here, the effect on addition of the polymers PVA, PVP, PEG and their combination on the preparation step were explored. The structural and morphological changes were analyzed by varying the substrate temperature, and its effect on the electrical and electrochemical performances were also studied. The thin films exhibited mixed micro and nanorod morphology. The XPS spectrum shows the stable 5+ oxidation state for vanadium. The electrochemical performance of the LiV 3 O 8 thin film made using PVA:PVP and PVA:PEG in the 1:1 ratio outperformed the material made using PVA alone. The aqueous LiNO 3 solution served as the electrolyte in three-electrode system. A specific capacitance of 359 F g−1 for a current density of 0.5 A g−1 as well as an areal capacitance of 143.8 F cm−2 at 0.2 mA cm−2 current density was obtained for the material made with PVA:PVP (1:1). • Binder free LiV 3 O 8 thin film by polymer-assisted spin coating method. • PVA:PVP assisted LiV 3 O 8 thin film has high electrochemical performance. • Thin films show mixed micro and nanorod morphology. • High specific capacitance of 359 F g−1 at 0.5 A g−1 on par with powder materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • The precipitates V 2 O 5 and Li 1.2 V 9 O 22 formed after heat treatment of V 2 O 5 -TeO 2 -Li 2 O. • Conversion of [VO 5 ] to [VO 4 ] changed the structure of [TeO 4 ] to [TeO 3 ]. • LiV 3 O 8 precipitated after 200 cycles promoting the reaction kinetics and capacity. • Different mechanisms of nanocrystals formation during cycling and thermal induced. • DFT model reveals lower diffusion barriers and higher electronic conductivity. V 2 O 5- TeO 2 (VT) is one of the promising vanadium-based materials for electrodes in Li-ion batteries, but its application is impeded by its low conductivity and poor capacity retention. The initial cyclic efficiency of V 2 O 5 -TeO 2 -Li 2 O(VTL) is enhanced by the addition of Li 2 O, implying that the pre-intercalation of Li-ions significantly improves the performance. The thermal treatment of VTL leads to the formation of V 2 O 5 and Li 1.2 V 9 O 22 crystals in the polycrystalline state (VTL-X). The VT, VTL and VTL-X exhibited specific capacitie of 821.9, 842.1, and 867.2 mAh g−1, respectively for the 1st cycle with respective retention rates of 19.6%, 19.5% and 27.5% after 1000 cycles. To elucidate the reaction mechanism, a structural simulation diagram of VTL during the heat treatment is modeled for the first time. The conversion of [VO 5 ] to [VO 4 ] transformed the structure of [TeO 4 ] into [TeO 3 ]. The DFT model reveals that the highest diffusion barriers for VTL and VTL-X are 0.49 eV and 0.16 eV, respectively. After crystallization, the conductivity and specific capacity of the resulting electrode material are significantly improved. LiV 3 O 8 precipitated after 200 cycles promotes the reaction kinetics and specific capacity. The synergistic effect of precipitating crystals impacts the glass structure, electrochemical reversibility, and reaction kinetics enormously, revealing the pivotal function of nanocrystal in regulating the battery cycling stability. The formation mechanism of nanocrystals during cycling is entirely different from thermal induced crystallization. The crystallization of glass electrodes during battery cycles helps to unfold the properties of glassy materials. [ABSTRACT FROM AUTHOR]

• The structure and energy storage mechanism of aqueous lithium-ion batteries are systematically described. • The structure, operation mechanism, and synthesis methods of LiV 3 O 8 are introduced in detail. • The modification methods of LiV 3 O 8 are systematically reviewed for the first time. • Some views on the modification strategy are put forward, which provides a reference direction for future research. The development of new energy makes modern society have a higher requirement for energy storage systems. At the same time, traditional lithium-ion batteries have their shortcomings, such as a shortage of metal lithium resources, harsh preparation conditions, and toxic organic electrolytes. Therefore, people have gradually begun to research aqueous lithium-ion batteries (ALIBs). Aqueous electrolytes can overcome the disadvantages of traditional organic electrolytes such as low safety and high production cost. Due to high specific discharge capacity and low operating voltage, LiV 3 O 8 is considered a promising anode for ALIBs. However, inherent low conductivity and unsatisfactory cycle performance limit its further application, so it is necessary and meaningful to conduct further research on LiV 3 O 8. This paper first introduces the structure, operation mechanism, and syntheses of LiV 3 O 8. Then the modification methods to improve the performance are reviewed from coating modification, introducing conductive agent, ion doping, and nano crystallization. Finally, reasonable suggestions and perspectives for LiV 3 O 8 are put forward. [ABSTRACT FROM AUTHOR]

Abstract: Lithium trivanadate (LiV3O8) crystallites have been synthesized via sol–gel processing using oxalic, tartaric, citric and malic acid as the chelating agents. The thermal decomposition process of the as-prepared LiV3O8 precursor was investigated by thermogravimetric (TG) and differential scanning calorimetry (DSC). The structure, morphology and electrochemical performance of the as-synthesized LiV3O8 samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and the galvanostatic charge–discharge test. Different chelating agents were introduced to investigate their effects on the products composition, morphology and electrochemical properties. Result show that the samples prepared with oxalic and tartaric acid are similar to show thin rod-like morphology in submicron size distribution while the samples prepared with citric and malic acid are found consisting of block-like crystallities in micron size. Further electrochemical results exhibit that the LiV3O8 particles with oxalic, tartaric, citric and malic acid exhibit an initial discharge capacity of 304.4mAh/g, 296.8mAh/g, 268.7mAh/g and 275.3mAh/g, respectively. After 20 cycles, they retain discharge capacity of 250.2mAh/g, 237.6mAh/g, 198.5mAh/g and 206.8mAh/g, respectively. [Copyright &y& Elsevier]

Abstract: Polyaniline–LiV3O8 (PANI–LiV3O8) nanocomposite has been chemically synthesized by an oxidative polymerization. The structure and performance of the sample have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), charge–discharge tests, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and the galvanostatic intermittent titration technique (GITT). In addition, the thermodynamics properties of as-prepared sample has also been studied. The PANI formed a network of electrically conductive paths among the LiV3O8 particles, so the active LiV3O8 material can be fully utilized for lithium extraction and insertion reactions and PANI–LiV3O8 nanocomposite exhibits much better electrochemical performance than bare LiV3O8. PANI incorporation in LiV3O8 could decrease the charge transfer resistance, increase the lithium diffusion coefficient during the lithiation process and improve the electrochemical reversibility. [Copyright &y& Elsevier]

Abstract: Lithium vanadium oxide (Li1+x V3O8) cathode materials were synthesized via a simple hydrothermal reaction followed by heat treatment at 300 or 400°C. From both XRD and TG/DTA analyses, a detailed comprehensive reaction sequence for the formation of single-phase LiV3O8 is proposed. Li1+x V3O8 (x=0.2) materials with different thermal histories show clear differences in morphologies and sizes, although they maintained an impurity-free single phase regardless of thermal treatment. Samples that were heat treated at 300°C show an agglomerated particle shape with many nanorod-like Li1+x V3O8 particles over the surface that enhance the surface area of the particles. In contrast, samples treated at 400°C have a bi-modal particle size distribution with improved crystallinity. Such differences in morphologies clearly influence the electrochemical properties. LiV3O8 cathode materials that were treated at 300 and 400°C showed initial discharge capacacities of 346.52 and 261.23mAh/g, respectively, and discharge capacities of 78.66 and 157.35mAh/g, respectively, after 100 cycles. The improved cyclability of LiV3O8 cathode materials that were heat treated at 400°C is due to their increased crystallinity and structural stability. [Copyright &y& Elsevier]

Abstract: Multiwalled carbon nanotube (MWCNT)-LiV3O8 nanocomposites have been fabricated by a facile sol–gel method without any pretreatment, surfactants or chelate agents added. The LiV3O8 nanoparticles grown on MWCNTs showed high specific discharge capacity up to 324mAhg−1, and greatly-enhanced cycling stability with a discharge capacity retention of 91% between cycles 10 and 40, while LiV3O8 nanopowders showed the specific discharge capacity only 233mAhg−1 and cycling stability with a capacity retention of 51% between cycles 10 and 40. The significantly improved electrochemical performance of the MWCNT–LiV3O8 nanocomposites is attributed to the formation of conductive networks by MWCNTs, and large surface areas of LiV3O8 nanoparticles grown on MWCNTs which stabilizes these nanoparticles against agglomeration. [Copyright &y& Elsevier]

Abstract: A polypyrrole-coated LiV3O8 nanocomposite was prepared as anode material (negative mass) for aqueous rechargeable lithium batteries and characterized by X-ray diffraction, scanning electron microscopy, and electrochemical measurements. Polypyrrole acts as a conducting matrix as well as a coating agent, which held LiV3O8 nanorods inside the particles during the charge/discharge cycles. Results show that the electrochemical performance of the PPy@LiV3O8 nanocomposite is significantly enhanced showing higher capacity and better rate capability as well as better cycling performance compared to pristine LiV3O8. [Copyright &y& Elsevier]

Abstract: LiV3O8–polyaniline nanocomposites have been synthesized via chemical oxidative polymerization directed by the anionic surfactant sodium dodecyl benzene sulfate. The polyaniline particles are uniformly coated on the LiV3O8 nanorods. The composite with 12 wt.% polyaniline retains a discharge capacity of 204 mAh g−1 after 100 cycles and had better rate capability (175 mAh g−1 at 2 C and 145 mAh g−1 at 4 C) than the bare LiV3O8 electrode in the potential range of 1.5–4.0 V. The polyaniline coating can buffer the dissolution into the LiPF6 electrode that occurs in LiV3O8 during cycling. The charge transfer resistance of the composite electrode was much lower than that of the bare LiV3O8 electrode, indicating that polyaniline coating significantly increases the electrical conductivity between the LiV3O8 nanorods. Polyaniline is a conductive binder which buffers the dissolution of LiV3O8 into the electrolyte and reduces the contact resistance among nanorods, so performance of the composite is significantly improved. [Copyright &y& Elsevier]

Abstract: Layered LiV3O8 as promising cathode material for rechargeable lithium-ion batteries has been efficiently synthesized by an improved spray-drying method followed by heating at different temperatures. Results of X-ray diffraction, scanning electron microscopy, charge–discharge test, cyclic voltammogram and electrochemical impedance spectroscopy indicate that the sample heat-treated at 300°C shows the best electrochemical performance. The LiV3O8 obtained at 300°C displays a maximum discharge capacity of 338.9mAhg−1 at current density of 25mAg−1 and after 20 cycles, a discharge capacity with 330.5mAhg−1 is obtained. Most important is that it displays an excellent cycling stability at large current density. It exhibits high discharge capacity of 251mAg−1 at current density of 125mAg−1 after 50 cycles. [Copyright &y& Elsevier]

Abstract: LiV3O8 cathode material was synthesized via a hydrothermal improved sol–gel process using LiOH, NH4VO3 and oxalic acid as raw materials. The thermal decomposition process of the as-prepared LiV3O8 precursor was investigated by thermogravimetric (TG) and differential scanning calorimetry (DSC). The structure, morphology and electrochemical performance of the as-synthesized LiV3O8 samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM) and the galvanostatic charge–discharge test. The effects of synthesis conditions on phases, structure and electrochemical performance of the LiV3O8 samples were particularly discussed. Result shows that pure LiV3O8 sample can be obtained at 300°C, which is much lower than that of normal citric assisted sol–gel method. The sample synthesized at 350°C exhibits the best electrochemical performance, which can present an initial discharge capacity of 301.1mAh/g at a current density of 50mA/g and maintain 271.6mA/g (about 90.2% of its initial value) after 10 cycles. [Copyright &y& Elsevier]

Abstract: A series of gallium-doped lithium trivanadates, LiV3−x Ga x O8 (x =0.00, 0.02, 0.04, 0.06, and 0.08), were prepared as cathode materials by a sol–gel method. The characterizations of the crystal structures and microstructures were investigated using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) mapping. Charge–discharge cycling performance, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were also used to characterize their electrochemical properties. The charge–discharge tests show that the electrochemical performance of LiV3O8 improved with Ga3+ doping and that LiV2.94Ga0.06O8 has the best electrochemical properties, exhibits a high discharge capacity of 277(±3)mAhg−1 and maintains a stable capacity of 226(±3)mAhg−1 within 50 cycles at the charge–discharge rate of 0.1C and in the voltage range of 1.8–4.0V. The LiV2.94Ga0.06O8 electrode also shows better electrochemical performances at higher rates. The EIS results show that both the charge-transfer resistance and the resistance of the lithium ion diffusion decreased greatly after doping, which is favorable for fast lithium-ion intercalations/deintercalations in bulk materials. [Copyright &y& Elsevier]

Abstract: A cathode material, LiV3O8, for rechargeable lithium-based batteries has been prepared via a combined freeze-drying method and appropriately post-treated in argon atmosphere. It was found that the sample post-treated at 300°C in Ar has the optimal performance. Electrochemical tests performed on this material demonstrated its very high insertion capacity of 347mAhg−1 (3.7 Li+ per LiV3O8) at a current density of 50mAg−1 (C/6). Most important is that it displayed an excellent cycling stability and after 60 cycles, a discharge capacity with 351mAhg−1 was obtained. It was proposed that a short-range crystallographic order had a stronger influence on the electrochemical performance of an electrode material in this work, instead of the surface area, particle size and crystalline degree, etc. [Copyright &y& Elsevier]

Abstract: Using a micro-patterned Si plate, a Li secondary cell was assembled and tested for its electrochemical properties. A micro-patterned Si plate was made by photolithography. This was followed by Pt coating and Li deposition. With a non-lithiated LiV3O8 cathode, a Li-deposited micro-patterned Si anode was assembled as a secondary cell. The cell exhibited an initial charge/discharge capacity of about 220mAhg−1 at a current density of 0.1 C-rate and it continued for more than 100cycles without failure. The morphologies of Li deposition/dissolution in the anode were observed via scanning electron microscopy (SEM). Dendrite behavior of the Li metal was not observed on the anode during the cyclic process. [ABSTRACT FROM AUTHOR]

Abstract: The electrochemical characterization related to the capacity fading of Li1.1V3O8 nano grains has been investigated. It reveals that capacity loss is associated to the use of liquid electrolyte and that it mainly stems from the active material irrespective of the nature of the liquid electrolyte, the water content, synthesis routes and the positive electrode chemistry. SEM and in operando XRD experiments allow elucidating undergoing physical processes. A film forms from electrolyte decomposition on the surface of the electrode and progressively propagates on cycling through the electrode thickness. Embedded grains become either less or none electrochemically reactive. In the former case, embedded grains give rise to strongly polarized and energetically less favored processes. In the latter case the capacity is not accessible anymore within the potential range resulting in capacity fading. [Copyright &y& Elsevier]

The layered cathode materials of LiV3O8 were successfully prepared for the lithium rechargeable battery via a wet-chemistry synthesis method. The as-synthesized materials were characterized by XRD (powder X-ray diffraction), SEM (scanning electron microscope) and galvanostatic charge-discharge test. The results indicate that this soft-synthesis technique offers reduced calcinations temperature, preferred surface morphology and better electrochemical performance. Among the thus-prepared materials, the material obtained at 350 °C demonstrates the first discharge capacity as high as 308 mAh g-1 in the range of 4.0 ∼ 1.7 Vat a current rate of 30 mA g-1 and remains at a stable discharge capacity of 250 mAh g-1 within 30 cycles. [ABSTRACT FROM AUTHOR]

Abstract: LiV3O8 thin films with a mixed amorphous–nanocrystalline microstructure were deposited on stainless steel substrates using radio-frequency (RF) magnetron sputtering for the first time. The films exhibited good performance as a cathode material for lithium ion batteries. Results indicate that the film electrodes had a smooth surface and consisted mainly of an amorphous structure containing nanocrystalline zones dispersed within it. Depending on its microstructure, the films delivered an initial discharge capacity as high as 382mAh/g and exhibited good capacity retention, with discharge capacity of 301mAh/g after 100 cycles representing a loss rate of 0.21% per cycle. [Copyright &y& Elsevier]

Abstract: LiV3O8, synthesized from V2O5 and LiOH, by heating of a suspension of V2O5 in a LiOH solution at a low-temperature (100–200°C), exhibits a high discharge capacity and excellent cyclic stability at a high current density as a cathode material of lithium-ion battery. The charge-discharge curve shows a maximum discharge capacity of 228.6mAhg−1 at a current density of 150mAg−1 (0.5C rate) and the 100 cycles discharge capacity remains 215mAhg−1. X-ray diffraction indicates the low degree of crystallinity and expanding of inter-plane distance of the LiV3O8 phase, and scanning electronic microscopy reveals the formation of nano-domain structures in the products, which account for the enhanced electrochemical performance. In contrast, the LiV3O8 phase formed at a higher temperature (300°C) consists of well-developed crystal phases, and coherently, results in a distinct reduction of discharge capacity with cycle numbers. Thus, an enhanced electrochemical performance has been achieved for LiV3O8 by the soft chemical method via a low-temperature heating process. [Copyright &y& Elsevier]

Abstract: One-dimensional (1D) nanorods of LiV3O8 single crystals have been fabricated by using well-defined home-made VO2 (B) nanorods as the vanadium resource, combined with a convenient solid-state reaction. The as-obtained LiV3O8 nanorods were characterized by XRD, TEM and SEM, indicating this material was highly crystalline and a single phase. The electrochemical performance of LiV3O8 nanorods as the positive electrode material for rechargeable lithium batteries was investigated, which demonstrated that as-prepared LiV3O8 nanorods exhibited as high as 348mAhg−1 discharge capacity in first cycle at 20mAg−1 current density, and still remained at 303mAhg−1 at 50mAg−1 afterwards; moreover, until 50 cycles, they kept 315mAhg−1, recorded at 50mAg−1. All these results imply that single-crystalline 1D nanorods of LiV3O8 are promising cathode material for rechargeable lithium batteries. [Copyright &y& Elsevier]

Abstract: Electrochemical intercalation of lithium ions from a saturated LiNO3 aqueous electrolyte solution into LiV3O8 prepared by a solid-state reaction at 680°C was studied with cyclic voltammetry and electrochemical impedance spectroscopy (EIS). Results show that there are three steps of intercalation in the presence of an aqueous electrolyte, in agreement with those previously observed with organic liquid electrolytes. In addition, variations of several parameters including the charge transfer resistance (R ct), the capacitance of the double layer (C DL), the Warburg diffusion impedance (Z w), and diffusion coefficient of lithium ions () during the intercalation process are reported. [Copyright &y& Elsevier]

Abstract: Submicron-sized LiV3O8 cathode materials were synthesized using a low-temperature reaction route with the help of grinding and the following calcination. A mixture of Li(ac)·2H2O(ac=acetate), NH4VO3 and excess H2C2O4·2H2O was used as starting material without any solvent. Characterization results of X-ray diffraction (XRD), scanning electron microscopy (SEM), charge–discharge test, and cyclic voltammogram (CV) indicated that the sample heat-treated at 350°C shows the best electrochemical performance. This low-temperature reaction route is a simple but efficient synthesis route for preparing high-performance LiV3O8 cathode material. [Copyright &y& Elsevier]

Abstract: Boron was doped into lithium trivanadate through an aqueous reaction process followed by heating at 100°C. The B-LiV3O8 materials as a cathode in lithium batteries exhibits a specific discharge capacity of 269.4mAhg−1 at first cycle and remains 232.5mAhg−1 at cycle 100, at a current density of 150mAhg−1 in the voltage range of 1.8–4.0V. The B-LiV3O8 materials show excellent stability, with the retention of 86.30% after 100 cycles. These result values are higher than those previous reports indicating B-LiV3O8 prepared by our synthesis method is a promising candidate as cathode material for rechargeable lithium batteries. The enhanced discharge capacities and their stabilities indicate that boron atoms promote lithium transferring and intercalating/deintercalating during the electrochemical processes and improve the electrochemical performance of LiV3O8 cathode. [Copyright &y& Elsevier]

Abstract: A series of cathode materials for lithium ion batteries with the formula LiV3−x Ni x O8 (x =0.000, 0.025, 0.050 and 0.100) have been synthesized by a novel low-temperature solid-state method. The synthesized cathode materials have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), discharge–charge test, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). These results indicate that LiV2.95Ni0.050O8 shows much better electrochemical performances than LiV3O8. This is due to better electrochemical reversibility and lower particle-to-particle resistance after Ni2+ doping. [Copyright &y& Elsevier]

Abstract: Lithium vanadium oxides were prepared by low heating solid-state method in which LiOH·H2O and NH4VO3 were used as starting reactants to synthesize a precursor containing Li and V, and then obtained the resulting products by calcining the precursor separately at 300, 400 and 500°C for 6h. Characterization by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and thermo-gravimetric analysis (TGA) shows that these oxides are ascribed as same as that of crystalline layered lithiated trivanadate and the crystallinity, size and morphology of the LiV3O8 varied with calcined temperature. The LiV3O8 compound prepared by this synthesis method gave a good charge–discharge and cycle performance. A specific capacity of 342mAhg−1 is obtained in the range of 1.8–3.8V in the first cycle when the sample obtained at 300°C. PEG added during the synthetic process makes the dimension of the particles uniform but does not affect the electrochemical properties of LiV3O8. [Copyright &y& Elsevier]

Abstract: LiV3O8 is a very promising cathode material for lithium secondary batteries. An EDTA-sol-gel method was proposed for the first time to obtain LiV3O8 at low temperature. LiAc·2H2O, NH4VO3 and EDTA were used as raw materials to prepare the precursor, and then the precursor was sintered to obtain the layered structure of LiV3O8. The effect of sintering temperature and duration on the quality of LiV3O8 was investigated. We also tested the electrochemical performances of LiV3O8 obtained through the method. The sample heated at 550 °C for 15 h has a single-phase layered structure and it has a first cycle discharge capacity of 251.7 mA h g−1 at the range of 1.8–3.6 V at 0.1 mA and an average capacity decay rate of 0.43% per cycle after 30 cycles. [Copyright &y& Elsevier]

Abstract: A series of cathode materials for lithium-ion batteries with the formula LiV3−2x Ni x Mn x O8 (0≤ x ≤0.100) were synthesized by a sol–gel method. The effects of Ni and Mn substitution on the structural, morphology and electrochemical properties of the cathode materials were investigated through X-ray diffraction (XRD), scanning electron microscopy (SEM), charge–discharge test, cyclic voltammogram (CV) and electrochemical impedance spectroscopy (EIS) experiments. Results show that an effective improved cycling performance is observed for Ni and Mn co-doped cathode materials, which is interpreted to be due to a greater reversibility during cycling and decrease of charge-transfer impedance. [Copyright &y& Elsevier]

Abstract: A novel lithium trivanadate/polypyrrole (LiV3O8–PPy) composite, suitable for lithium-ion battery cathodes, was synthesized by dispersing LiV3O8 and PPy powders in ethanol followed by heating. The polypyrrole acts as a conducting matrix, a binder and an active material, as well as a volume change buffer agent, which holds the LiV3O8 particles in place during the charge/discharge cycles. The new material was characterized by scanning electron microscopy. It was found that polypyrrole particles were uniformly distributed among the LiV3O8 powders, which could significantly enhance the electrical conductivity and stability of the composite electrode. The composite containing 20wt% PPy exhibits a good reversibility, higher coulombic efficiency and better cycle life than the bare LiV3O8 electrode. [Copyright &y& Elsevier]

Abstract: Crystalline LiV3O8 and LiMn2O4 were prepared by conventional solid-state reaction and characterized by X-ray diffraction analysis. Cyclic voltammetry technique was employed to evaluate the electrochemical behaviors of LiV3O8 and LiMn2O4 in 2mol/l Li2SO4 aqueous solution, and the results show that both LiV3O8 and LiMn2O4 are very stable in this aqueous electrolyte and can be used as the negative and positive electrode material without evident hydrogen or oxygen evolution. An aqueous rechargeable lithium battery (ARLB) was fabricated by using the above two intercalation compounds as the negative and positive electrodes. This battery exhibits good cycling behavior and the average discharge voltage is about 1.04V. [Copyright &y& Elsevier]

Abstract: Silicon doped lithium trivanadate LiSi x V3O8 (x =0.000, 0.025, 0.050, 0.075, 0.100) were prepared via a solid state reaction and then aqueous redox reactions. The compositions, structures and electrochemical properties of the materials were intensively characterized by inductive coupled plasma atomic emission spectroscopy (ICP-AES), powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), cyclic voltammetry (CV) and galvanostatic charge–discharge cycle tests. The results show there are many advantages of the synthetic and modification method in this work such as simple elemental composition control. The structures of silicon doped samples behave readily for lithium transfer and intercalating/de-intercalating. The outstanding performances of the materials benefit from silicon doping significantly. LiSi0.050V3O8 showed the best characteristics among the as-prepared materials. The specific discharge capacity of LiSi0.050V3O8 remained 224.3 mAh·g−1 at cycle 150 and 143.0 mAh·g−1 at cycle 300 at a current density of 150 mA·g−1 in the voltage range of 1.8–4.0 V. [Copyright &y& Elsevier]

Mechanical activation (MA) has been used to prepare high dispersed lithium-transition metal cathode materials and inorganic solid lithium-ion electrolytes for rechargeable lithium batteries. It has been shown that materials with low-dimensional (submicron) particles have notable advantages: i) for insertion electrodes, i.e. when the first electrochemical step is intercalation of Li+ ions (eg., LiMn2O4–3V, LiV3O8); ii) for cathodes with poor electronic conductivity (eg., LiFePO4); iii) for materials (electrodes and electrolytes) used in all solid state inorganic lithium batteries. Decreased particle size of as prepared cathodes leads to enhanced practical capacity because of increased quantity of particles that can be utilized, while the presence of structural disordering results in better structural stability upon intercalation of lithium ions and smoother discharge curves. The conductivity of the LiTi2(PO4)3 and Li1.3Al0.3Ti1.7(PO4)3 lithium-ion solid electrolytes prepared by using MA was of 2–3 order of magnitude higher than that for nonactivated samples owing to the absence of non-conductive impurities and lower grain boundary resistance. [Copyright &y& Elsevier]

Aqueous zinc-ion batteries (AZIBs) are promising candidates for large-scale energy storage because of their low cost and high safety. However, their practical applications are impeded by low energy density and short service life. Here, an aqueous Zn2+/Li+ hybrid-ion battery is fabricated using the LiV3O8 nanorods as the cathode, metallic Zn as the anode, and 3 M Zn(OTf)2 + 0.5 M LiOTf aqueous solution as the electrolyte. Compared with the batteries using pure 3 M Zn(OTf)2 electrolyte, the cycle performance of the hybrid-ion battery is significantly improved. After 4000 cycles at 5 A g1, the remaining capacity is 163.9 mA h g−1 with impressive capacity retention of 87.0%. Ex-situ XRD, ex-situ XPS, and SEM tests demonstrate that the hybrid electrolyte can inhibit the formation of the irreversible Zn3(OH)2V2O7·2H2O by-product and restrict Zn dendrite growth during cycling, thereby improving the cycle performance of the batteries. [ABSTRACT FROM AUTHOR]

Abstract: LiV3O8 has been synthesized by an improved spray-drying method which is dozens of times faster than the conventional route. The as-obtained powder was characterized by XRD, indicating this material was almost pure LiV3O8. The electrochemical performance of LiV3O8 as the cathode material was investigated, which demonstrated that as-prepared LiV3O8 exhibited as high as 340.2mAhg−1 discharge capacity in first cycle at current density of 25mAg−1; moreover, after 100 cycles at the current density of 125mAg−1, it still maintained a high discharge capacity of 241.8mAhg−1, suggesting its promising application as the cathode material for Li-ion batteries. [Copyright &y& Elsevier]

Abstract: Submicron sized sheet-like LiV3O8 cathode materials for lithium secondary batteries were synthesized via a simple processing, microwave hydrothermal improved low temperature solid-state reaction, with LiOH·H2O, NH4VO3 and PVP as raw materials. The LiV3O8 crystallites prepared without PVP consists of smaller particle size than that prepared with PVP, and it exhibits relatively better electrochemical performance. The LiV3O8 crystallites prepared without PVP delivers an initial discharge capacity of 282.2mAh/g at a current density of 100mA/g. After 20 cycles, the discharge capacity retains 228.4mAh/g corresponded to 80.9% of the initial value. The small submicron sized sheet-like LiV3O8 crystallites are expected to shorten the Li+ ions diffusion path for its electrochemical properties. The good electrochemical properties of the as-synthesized LiV3O8 make them a promising candidate as a cathode material for lithium secondary batteries. [Copyright &y& Elsevier]

Abstract: Single-crystalline LiV3O8 nanobelts have been synthesized by using V2O5 nanobelts as the vanadium resource via a facile solid-state reaction method. The LiV3O8 nanobelts with thickness of less than 20nm, widths of 100–300nm, and length up to several micrometers can grow along the [01] direction. The small thickness of LiV3O8 nanobelts are expected to shorten the Li+ ion diffusion distance for the improved electrochemical performance of electrode material. The influence of types of lithium salts on the morphologies and sizes of LiV3O8 nanostructures has been investigated. When used as the cathode material in rechargeable lithium batteries, LiV3O8 nanobelts exhibit stable lithium-ion intercalation/deintercalation reversibility and deliver initial specific discharge capacities of around 356.2mAh/g at 0.02A/g, 273.6mAh/g at 0.05A/g, and 234.0mAh/g at 0.1A/g, respectively. After 30 cycles, the specific discharge capacities are lowered to 298.6mAh/g at 0.02A/g, 234.5mAh/g at 0.05A/g, and 195.5mAh/g at 0.1A/g, respectively. The good electrochemical properties of LiV3O8 nanobelts make them a promising candidate as a cathode material for rechargeable lithium batteries. [Copyright &y& Elsevier]

LiV 3 O 8 attracts much research interest because it is a high theoretical specific capacity and low cost cathode material of lithium ion battery and is also a good candidate for the anode material of aqueous lithium ion battery. Therefore, it is worth of further investigation on preparing LiV 3 O 8 materials. However, when preparing LiV 3 O 8 materials, impurities such as L 0.3 V 2 O 5 are usually accompanied. Besides, the calcination temperature and time when preparing LiV 3 O 8 materials in different literatures are diverse. To solve this problem, the LiV 3 O 8 crystal are prepared and the optimum calcination conditions and the optimum stoichiometry of Li:V are systematic studied. The optimum calcination temperature and time is chosen at 400 °C for 5 h. The best stoichiometry of Li:V is 1.15:3. The LiV 3 O 8 material prepared in this study has a good purity and no impurity is found. When act as cathode of LIBs, the LiV 3 O 8 crystal has relatively high discharge capacity as 220–240 mAh g−1. Image 1 • Pure crystalline LiV 3 O 8 is prepared without impurities by sol-gel and subsequent solid state calcination. • The influences of calcination temperature, time, and stoichiometry on prepare LiV 3 O 8 systematically investigated. • The present work solved the problem of diversed calcination temperature and time when preparing LiV 3 O 8 materials in different literatures. [ABSTRACT FROM AUTHOR]