Designed constitution of NiO/Ni nanostructured electrode for high performance lithium ion battery

Gallium-Telluride-Based Composite as Promising Lithium Storage Material

Various applications of gallium telluride have been investigated, such as in optoelectronic devices, radiation detectors, solar cells, and semiconductors, owing to its unique electronic, mechanical, and structural properties. Among the various forms of gallium telluride (e.g., GaTe, Ga₃Te₄, Ga₂Te₃, and Ga₂Te₅), we propose a gallium (III) telluride (Ga₂Te₃)-based composite (Ga₂Te₃-TiO₂-C) as a prospective anode for Li-ion batteries (LIBs). The lithiation/delithiation phase change mechanism of Ga₂Te₃ was examined. The existence of the TiO₂-C hybrid buffering matrix improved the electrical conductivity as well as mechanical integrity of the composite anode for LIBs. Furthermore, the impact of the C concentration on the performance of Ga₂Te₃-TiO₂-C was comprehensively studied through cyclic voltammetry, differential capacity analysis, and electrochemical impedance spectroscopy. The Ga₂Te₃-TiO₂-C electrode showed high rate capability (capacity retention of 96% at 10 A g^-1 relative to 0.1 A g^-1) as well as high reversible specific capacity (769 mAh g^-1 after 300 cycles at 100 mA g^-1). The capacity of Ga₂Te₃-TiO₂-C was enhanced by the synergistic interaction of TiO₂ and amorphous C. It thereby outperformed the majority of the most recent Ga-based LIB electrodes. Thus, Ga₂Te₃-TiO₂-C can be thought of as a prospective anode for LIBs in the future.

Electrospinning synthesis of amorphous NiMoO4/graphene dendritic nanofibers as excellent anodes for sodium ion batteries

Metal molybdates have attracted considerable attention as promising anode materials for sodium ion batteries (SIBs) due to their high theoretical specific capacity and excellent electrochemical performance. However, their low rate capacity and rapid capacity attenuation hinder their application in SIBs. Here, amorphous NiMoO₄/graphene nanofibers were prepared via an electrospinning method. The electrochemical performance of NiMoO₄ was first reported as the anode for SIBs. Amazingly, the amorphous NiMoO₄/graphene delivered an outstanding specific capacity of 260 mAh g^-1 after 100 cycles at 100 mA g^-1 at a potential range from 0.01-2.7 V and an excellent rate performance of 160 mAh g^-1 at 1 A g^-1. The superior electrochemical properties of amorphous NiMoO₄ can be ascribed to its amorphous structure and reduced diffusion distance, and the strong synergy of NiMoO₄ and graphene.

CO2 Conversion into N-Doped Porous Carbon-Encapsulated NiO/Ni Composite Nanomaterials as Outstanding Anode Material of Li Battery

N-doped porous carbon encapsulated NiO/Ni composite nanomaterials (N-doped NiO/Ni@C) was successfully obtained by a one-step solution combustion method. This study demonstrates a one-step combustion method to synthesize n-doped porous carbon encapsulated NiO/Ni composite nanomaterials, using carbon dioxide as the carbon source, nickel nitrate as the nickel source, and hydrazine hydrate as the reaction solution. Spherical NiO nanoparticles with a particle size of 20 nm were uniformly distributed in the carbon matrix. The load of NiO/Ni can be controlled by the amount of nickel nitrate. The range of carbon content of recovered samples is 69-87 at%. The content of incorporated nitrogen for recovered samples is 1.94 at%. As the anode of lithium ion battery, the composite material exhibits high capacity, excellent multiplier performance and stable circulation performance. N-doped NiO/Ni@C-2 was applied to lithium ion batteries, and its reversible capacity maximum is 980 mAh g^-1 after 100 cycles at the current density of 0.1 A g^-1. Its excellent electrochemical properties imply its high potential application for high-performance lithium-ion battery anode materials.

Oxalate-derived porous prismatic nickel/nickel oxide nanocomposites toward lithium-ion battery

NiO is a highly appealing anode material for lithium-ion batteries (LIBs) owing to its relatively high Li storage capacity. However, its low electrical conductivity and large volume change during the battery cycling process limit its application. Here, we fabricate a series of porous Ni/NiO (M) nanocomposites through the direct pyrolysis of a nickel oxalate precursor and adjust the Ni(0) content by varying the pyrolysis temperature. The porous architecture is beneficial for alleviating the volume expansion/constriction during cycling. The Ni in the composites accelerates the electrochemical reaction kinetics and enhances the conductivity of the electrode materials. The M-2 electrode with a 17.9% Ni(0) content realizes a high reversible capacity (633.7 mA h g^-1 after 100 cycles at 0.2 A g^-1) and exhibits outstanding rate capability (307.6 mA h g^-1 after 250 cycles at 1 A g^-1). This work can not only supply an approach to adjust the content of an element with specific valence state, but also provide an inspiration for the fabrication of porous metal/metal oxide anode materials in LIBs.

Review of the Design of Current Collectors for Improving the Battery Performance in Lithium-Ion and Post-Lithium-Ion Batteries

Current collectors (CCs) are an important and indispensable constituent of lithium-ion batteries (LIBs) and other batteries. CCs serve a vital bridge function in supporting active materials such as cathode and anode materials, binders, and conductive additives, as well as electrochemically connecting the overall structure of anodes and cathodes with an external circuit. Recently, various factors of CCs such as the thickness, hardness, compositions, coating layers, and structures have been modified to improve aspects of battery performance such as the charge/discharge cyclability, energy density, and the rate performance of a cell. In this paper, the details of interesting and useful attempts of preparing CCs for high battery performance in lithium-ion and post-lithium-ion batteries are reviewed. The advantages and disadvantages of these attempts are discussed.

Fast-Charging High-Energy Battery-Supercapacitor Hybrid: Anodic Reduced Graphene Oxide-Vanadium(IV) Oxide Sheet-on-Sheet Heterostructure

The battery-supercapacitor hybrid (BSH) device has potential applications in energy storage and can be a remedy for low-power batteries and low-energy supercapacitors. Although several studies have investigated electrode materials (particularly for a battery-type anode material) and design for BSHs, the energy density and power density are insufficient (far from the levels required for practical applications). Herein, a hierarchical vanadium(IV) oxide on reduced graphene oxide (rGO@VO₂) heterostructure as an anode and activated carbon on carbon cloth (AC@CC) as a cathode are proposed for fabricating an advanced BSH. The mixed valency of V ions inside the as-prepared VO₂ matrix (V³⁺ and V⁴⁺) facilitates redox reactions at a low potential, giving rise to rGO@VO₂ as a typical anode with a working potential of 0.01-3 V (vs Li/Li⁺). The sheet-on-sheet heterostructured rGO@VO₂ yields a high specific capacity of 1214 mAh g^-1 at 0.1 A g^-1 after 120 cycles, with a high rate capability and stability. The rGO@VO₂//AC@CC BSH device exhibits a maximum gravimetric energy density of 126.7 Wh kg^-1 and a maximum gravimetric power density of ∼10 000 W kg^-1 within a working voltage range of 1-4 V. Moreover, it exhibits fast charging times of 5 and 834 s with energy densities of 15.6 and 82 Wh kg ^-1, respectively.

Fabrication of Cu2 O-based Materials for Lithium-Ion Batteries

The improvement of the performance of advanced batteries has played a key role in the energy research community since its inception. Therefore, it is necessary to explore high-performance materials for applications in advanced batteries. Among the variety of materials applied in batteries, much research has been dedicated to examine cuprous oxide materials as working electrodes in lithium cells to check their suitability as anodes for Li-ion cells and this has revealed great working capacities because of their specific characteristics (polymorphic forms, controllable structure, high cycling capacity, etc.). Thus, cuprous oxide and its composites will be fully introduced in this Review for their applications in advanced batteries. It is believed that, in the future, both the study and the impact of cuprous oxide and its composites will be much more profound and lasting.

In situ fabrication of a graphene-coated three-dimensional nickel oxide anode for high-capacity lithium-ion batteries

The high theoretical specific capacity of nickel oxide (NiO) makes it attractive as a high-efficiency electrode material for electrochemical energy storage. However, its application is limited due to its inferior electrochemical performance and complicated electrode fabrication process. Here, we developed an in situ fabrication of a graphene-coated, three-dimensional (3D) NiO–Ni structure by simple chemical vapor deposition (CVD). We synthesized NiO layers on Ni foam through a thermal oxidation process; subsequently, we grew graphene layers directly on the surface of NiO after a hydrogen-assisted reduction process. The uniform graphene coating renders high electrical conductivity, structural flexibility and high elastic modulus at atomic thickness. The graphene-coated 3D NiO–Ni structure delivered a high areal density of ∼23 mg cm⁻². It also exhibits a high areal capacity of 1.2 mA h cm⁻² at 0.1 mA cm⁻² for its Li-ion battery performance. The high capacity is attributed to the high surface area of the 3D structure and the unique properties of the graphene layers on the NiO anode. Since the entire process is carried out in one CVD system, the fabrication of such a graphene-coated 3D NiO–Ni anode is simple and scalable for practical applications.

The processing of graphene coated NiO–Ni anode using one CVD system delivered high Li-ion battery performance.

NiO-nanoflakes grafted graphene: an excellent photocatalyst and a novel nanomaterial for achieving complete pathogen control

The increased levels of industrial pollutants in water and of drug-resistant pathogens more generally are a serious threat to human and aquatic life. Herein, we present the solar-light-induced dye removal and bactericidal properties of nickel oxide (NiO) and graphene nanoplatelet (GNP) nanocomposites. The conducting nature of GNPs is the key factor that accounts for the enhanced photocatalytic and antibacterial activity. Remarkably, the graphene/NiO nanocomposite shows outstanding photocatalytic activity (99% degradation) as compared to NiO (34%) alone, which makes it a potential candidate for the depollution of dye-contaminated water. In addition, the optimized amount of GNPs in the graphene/NiO nanocomposite renders it an exceptional antibacterial material, producing 100% growth inhibition of pathogenic microorganisms (both Gram-positive and Gram-negative bacteria). Therefore, the graphene/NiO nanocomposite can be an innovative material to achieve complete pathogen control, alongside being an economic solution for water treatment.

Study on the Electrochemical Reaction Mechanism of NiFe2O4 as a High-Performance Anode for Li-Ion Batteries

Nickel ferrite (NiFe₂O₄) has been previously shown to have a promising electrochemical performance for lithium-ion batteries (LIBs) as an anode material. However, associated electrochemical processes, along with structural changes, during conversion reactions are hardly studied. Nanocrystalline NiFe₂O₄ was synthesized with the aid of a simple citric acid assisted sol-gel method and tested as a negative electrode for LIBs. After 100 cycles at a constant current density of 0.5 A g^-1 (about a 0.5 C-rate), the synthesized NiFe₂O₄ electrode provided a stable reversible capacity of 786 mAh g^-1 with a capacity retention greater than 85%. The NiFe₂O₄ electrode achieved a specific capacity of 365 mAh g^-1 when cycled at a current density of 10 A g^-1 (about a 10 C-rate). At such a high current density, this is an outstanding capacity for NiFe₂O₄ nanoparticles as an anode. Ex-situ X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) were employed at different potential states during the cell operation to elucidate the conversion process of a NiFe₂O₄ anode and the capacity contribution from either Ni or Fe. Investigation reveals that the lithium extraction reaction does not fully agree with the previously reported one and is found to be a hindered oxidation of metallic nickel to nickel oxide in the applied potential window. Our findings suggest that iron is participating in an electrochemical reaction with full reversibility and forms iron oxide in the fully charged state, while nickel is found to be the cause of partial irreversible capacity where it exists in both metallic nickel and nickel oxide phases.

Two isomorphous coordination polymer-derived metal oxides as high-performance anodes for lithium-ion batteries

Two Co₃O₄ and NiO anodes for LIBs derived from novel, isomorphous 2D coordination polymers displayed high rate cycling performance.

Improved lithium-ion battery anode capacity with a network of easily fabricated spindle-like carbon nanofibers

A novel network of spindle-like carbon nanofibers was fabricated via a simplified synthesis involving electrospinning followed by preoxidation in air and postcarbonization in Ar. Not only was the as-obtained carbon network comprised of beads of spindle-like nanofibers but the cubic MnO phase and N elements were successfully anchored into the amorphous carbon matrix. When directly used as a binder-free anode for lithium-ion batteries, the network showed excellent electrochemical performance with high capacity, good rate capacity and reliable cycling stability. Under a current density of 0.2 A g^-1, it delivered a high reversible capacity of 875.5 mAh g^-1 after 200 cycles and 1005.5 mAh g^-1 after 250 cycles with a significant coulombic efficiency of 99.5%.

A super high performance asymmetric supercapacitor based on Co3S4/NiS nanoplates electrodes

In this paper, we successfully designed and synthesized Co₃S₄/NiS nanoplates by both ion-exchange action and Ostwald ripening reactions during the sulfurization process.

The charge/discharge mechanism and electrochemical performance of CuV2O6 as a new anode material for Li-ion batteries

CuV₂O₆/NG is demonstrated to be a new ideal anode material for Li-ion batteries.

Excellent electrochemical performance of NiV3O8/natural graphite anodes via novel in situ electrochemical reconstruction

NiV₃O₈/natural graphite anodes show excellent electrochemical performance via a novel in situ electrochemical reconstruction.

N-doped amorphous carbon coated Fe3O4/SnO2 coaxial nanofibers as a binder-free self-supported electrode for lithium ion batteries

N-doped amorphous carbon coated Fe3O4/SnO2 coaxial nanofibers were prepared via a facile approach. The core composite nanofibers were first made by electrospinning technology, then the shells were conformally coated using the chemical bath deposition and subsequent carbonization with polydopamine as a carbon source. When applied as a binder-free self-supported anode for lithium ion batteries, the coaxial nanofibers displayed an enhanced electrochemical storage capacity and excellent rate performance. The morphology of the interwoven nanofibers was maintained even after the rate cycle test. The superior electrochemical performance originates in the structural stability of the N-doped amorphous carbon shells formed by carbonizing polydopamine.

Solution synthesis of metal oxides for electrochemical energy storage applications

This article provides an overview of solution-based methods for the controllable synthesis of metal oxides and their applications for electrochemical energy storage. Typical solution synthesis strategies are summarized and the detailed chemical reactions are elaborated for several common nanostructured transition metal oxides and their composites. The merits and demerits of these synthesis methods and some important considerations are discussed in association with their electrochemical performance. We also propose the basic guideline for designing advanced nanostructure electrode materials, and the future research trend in the development of high power and energy density electrochemical energy storage devices.