Ni3V2O8 nanoparticles as an excellent anode material for high-energy lithium-ion batteries

Hierarchical Ni3V2O8@N-Doped Carbon Hollow Double-Shell Microspheres for High-Performance Lithium-Ion Storage

Transition metal oxides (TMOs) are highly dense in energy and considered as promising anode materials for a new generation of alkaline ion batteries. However, their electrode structure is disrupted due to significant volume changes during charging and discharging, resulting in the short cycle life of batteries. In this paper, the hierarchical Ni3V2O8@N-doped carbon (Ni3V2O8@NC) hollow double-shell microspheres were prepared and used as electrode materials for lithium-ion batteries (LIBs). The utilization efficiency and ion transfer rate of Ni3V2O8 were improved by the hollow microsphere structure formed through nanoparticle self-assembly. Furthermore, the uniform N-doped carbon layer not only enhanced the structural stability of Ni3V2O8, but also improved the overall electrical conductivity of the composite. The Ni3V2O8@NC electrode has an initial discharge capacity of up to 1167.3 mAh g-1 at a current density of 0.3 A g-1, a reversible capacity of up to 726.5 mAh g-1 after 200 cycles, and still has a capacity of 567.6 mAh g-1 after 500 cycles at a current density of 1 A g-1, indicating that the material has good cycle stability and high-rate capability. This work presents new findings on the design and fabrication of complex porous double-shell nanostructures.

NiCo2V2O8@NC Spheres with Mesoporous Yolk- Bilayer Hierarchical Structure for Enhanced Lithium Storage

Metal vanadates as negative electrode materials for lithium-ion batteries have attracted widespread attention, attributed to their substantial capacity, broad availability, and exceptional safety. In this study, NiCo2V2O8@NC microspheres featuring a yolk-double shell structure were successfully synthesized via ion exchange reactions and surface deposition techniques, employing metal glycerolate as a template. Owing to the bimetallic cobalt-nickel synergistic effect and the N-doped carbon network, this configuration not only optimizes the pore structure but also enhances conductivity, thereby augmenting the stability of the overall structure. The unique yolk-double shell design significantly enhances the utilization of active components and reduces the ion transport distance, thereby achieving high capacity. Thanks to the synergistic effects of this bimetallic and intricate structure, the material demonstrates exceptional capacity and cycle stability in lithium storage. The initial discharge capacity possesses 1522 mAh g-1 at a current density of 0.2 A g-1, with the reversible capacity still maintained at 1197 mAh g-1 after 100 cycles. In addition, at a high current density of 0.5 A g-1, the initial discharge capacity is 1487 mAh g-1, with a reversible capacity of 747 mAh g-1 maintained after 500 cycles. This study offers a perspective and methodology for the design and fabrication of complex porous double shell nanostructures.

Surfactant effect on energy storage performance of hydrothermally synthesized Ni3V2O8

We report a study to improve the ternary oxide Ni3V2O8's electrochemical energy storage capabilities through correct surfactanization during hydrothermal synthesis. In this study, Ni3V2O8nanomaterials were synthesized in three different forms: one with a cationic surfactant (CTAB), one with an anionic surfactant (SLS), and one without any surfactant. FESEM study reveals that all the synthesized Ni3V2O8nanomaterials had a small stone-like morphology. The electrochemical study showed that anionic surfactant-assisted Ni3V2O8(NVSLS) had a maximum of 972 F g-1specific capacitance at 1 A g-1current density, whereas cationic surfactant-assisted Ni3V2O8(NVCTAB) had the lowest specific capacitance of 162 F g-1. The specific capacitance and the capacitance retention of the NVSLS(85% after 4000 cycles) based electrode was much better than that of the NVCTAB(76% after 4000 cycles) based electrode. The improved energy storage properties of the NVSLSelectrode are attributed to its high diffusion coefficient, high surface area, and enriched elemental nickel, as compared to the NVCTABelectrode. All these excellent electrochemical properties of NVSLSelectrode indicates their potential usage in asymmetric supercapacitor application.

Nickel vanadate nitrogen-doped carbon nanocomposites for high-performance supercapacitor electrode

A nickel-vanadium-based bimetallic precursor was produced using the polymerization process by urea-formaldehyde copolymers. The precursor was then calcined at 800 °C in an argon ambiance to form a Ni3V2O8-NC magnetic nanocomposite. Powerful techniques were used to study the physical characteristics and chemical composition of the fabricated Ni3V2O8-NC electrode. PXRD, Raman, and FTIR analyses proved that the crystal structure of Ni3V2O8-NC included N-doped graphitic carbon. FESEM and TEM analyses imaging showed the distribution of the Ni3V2O8 nanoparticles on the layered graphitic carbon structure. TEM images showed the prepared sample has a particle size of around 10-15 nm with an enhanced active site area of 146 m2/g, as demonstrated by BET analysis. Ni3V2O8-NC nanocomposite exhibits magnetic behaviors and a magnetization saturation value of 35.99 emu/g. The electrochemical (EC) studies of the synthesized Ni3V2O8-NC electrode proceeded in an EC workstation of three-electrode. In a 5 M potassium hydroxide as an electrolyte, the cyclic voltmeter exhibited an enhanced capacitance (CS) of 915 F/g at 50 mV/s. Galvanic charge-discharge (GCD) study also exhibited a superior capacitive improvement of 1045 F/g at a current density (It) of 10 A/g. Moreover, the fabricated Ni3V2O8-NC nanocomposite displays a good power density (Pt) of 356.67 W/kg, improved ion accessibility, and substantial charge storage. At the high energy density (Et) of 67.34 W h/kg, the obtained Pt was 285.17 W/kg. The enhanced GCD rate, cycle stability, and Et of the Ni3V2O8-NC magnetic nanocomposite nominate the sample as an excellent supercapacitor electrode. This study paves the way for developing effective, efficient, affordable, and ecologically friendly electrode materials.

Rational Synthesis of "Grape-like" Ni2 V2 O7 Microspheres as High-capacity Anodes for Rechargeable Lithium Batteries

Vanadates have received booming attention recently as promising materials for extensive electrochemical devices such as batteries and electrocatalysis. However, the enormous difficulties of achieving pure-phase transition metal vanadates, especially for nickel-based, hinder their exploitations. Herein, for the first time, by controlling the amount of ethylene glycol (EG) and reaction time, grape-like Ni₂ V₂ O₇ (or V₂ O₅ /Ni₂ V₂ O₇ ) microspheres were rationally fabricated. It is demonstrated that the EG can chelate both Ni²⁺ and VO₃ ^- to form organometallic precursors. As anode in lithium-ion batteries (LIBs), it could deliver superior reversible capacity of 1050 mAh/g at 0.1 A/g and excellent rate capability of 600 mAh/g at 4 A/g. The facile hydrothermal synthesis broadens the material variety of nickel vanadates and offers new opportunities for their wider applications in electrochemistry.

Facile One-Step Hydrothermal Synthesis of the rGO@Ni3V2O8 Interconnected Hollow Microspheres Composite for Lithium-Ion Batteries

Low-cost, vanadium-based mixed metal oxides mostly have a layered crystal structure with excellent kinetics for lithium-ion batteries, providing high energy density. The existence of multiple oxidation states and the coordination chemistry of vanadium require cost-effective, robust techniques to synthesize the scaling up of their morphology and surface properties. Hydrothermal synthesis is one of the most suitable techniques to achieve pure phase and multiple morphologies under various conditions of temperature and pressure. We attained a simple one-step hydrothermal approach to synthesize the reduced graphene oxide coated Nickel Vanadate (rGO@Ni₃V₂O₈) composite with interconnected hollow microspheres. The self-assembly route produced microspheres, which were interconnected under hydrothermal treatment. Cyclic performance determined the initial discharge/charge capacities of 1209.76/839.85 mAh g⁻¹ at the current density of 200 mA g⁻¹ with a columbic efficiency of 69.42%, which improved to 99.64% after 100 cycles. High electrochemical performance was observed due to high surface area, the porous nature of the interconnected hollow microspheres, and rGO induction. These properties increased the contact area between electrode and electrolyte, the active surface of the electrodes, and enhanced electrolyte penetration, which improved Li-ion diffusivity and electronic conductivity.

Synthesis of a three-dimensional cross-linked Ni-V2O5 nanomaterial in an ionic liquid for lithium-ion batteries

A three-dimensional cross-linked Ni-V₂O₅ nanomaterial with a particle size of 250-300 nm was successfully prepared in a 1-butyl-3-methylimidazole bromide ionic liquid (IL). The formation of this structure may follow the rule of dissolution-recrystallization and the ionic liquid, as both a dissolution and structure-directing agent, plays an important role in the formation of the material. After calcination of the precursor, the active material (Ni-V₂O₅-IL) was used as an anode for lithium-ion batteries. The designed anode exhibited excellent electrochemical performance with 765 mA h g^-1 at a current density of 0.3 A g^-1 after 300 cycles, which is much higher than that of a NiVO-W material prepared via a hydrothermal method (305 mA h g^-1). These results show the remarkable superiority of this novel electrode material synthesized in an ionic liquid.

Rational design of marigold-shaped composite Ni3V2O8 flowers: a promising catalyst for the oxygen evolution reaction

Ni₃V₂O₈ flowers designed by the thermal decay of molecular precursors show excellent OER activity with an overpotential of 328 mV.

Performance of SiO2/Ag Core/Shell particles in sonocatalalytic degradation of Rhodamine B

In this study, SiO₂/Ag Core/Shell nanoparticles was prepared and sonocatalytic activity of prepared catalyst was investigated by using Rhodamine B as model contaminant, at 35 kHz using ultrasonic power of 160 W within 90 min. The change in efficiency in the sonocatalytic degradation of Rhodamine B catalyzed by SiO₂/Ag Core/Shell nanoparticles with respect to the initial concentration of dye, catalyst amount and temperature were firstly investigated. Optimal conditions were found as follows: catalyst amount = 15 mg/L, Temperature = 25 °C and initial concentration of dye = 10 ppm. Influence factors such as pH of solution, O₂ saturation of solution and the concentration of H₂O₂ added to the solution, on degradation efficiency in presence of catalyst, were investigated. SiO₂/Ag Core/Shell nanoparticles showed higher sonocatalytic activity at pH = 7 with respect to acidic and alkaline conditions. Degradation efficiency was reached up to 67% in experiments which air pumped (0.6 L/min) through the solution with in 90 min. It was observed that the dye removal increased via increase while H₂O₂ concentration lower than 10 mM. Higher concentration of H₂O₂ than the optimal concentration had adverse effect on degradation efficiency. Our results showed that the SiO₂/Ag Core/Shell nanoparticles were active catalyst for sonocatalytic degradation of dyes. Reusability of the catalyst was investigated.