Co3O4/C nanocapsules with onion-like carbon shells as anode material for lithium ion batteries

Review of metal oxides as anode materials for lithium-ion batteries

Lithium-ion batteries with a stable circulation capacity, high energy density and good safety are widely used in automobiles, mobile phones, manufacturing and other fields. MOs due to their large theoretical capacity, simple processing and abundant reserves, and used as anode materials for LIBs, have attracted much attention. Three electrochemical mechanisms of MOs are reviewed in this paper. In addition, research progress of MOs and prospects for their further applications in LIBs are summarized.

Soft-chemistry synthesis, solubility and interlayer spacing of carbon nano-onions

Carbon nano-onions (CNOs), as one of the allotropes of carbon, have attracted great attention because of their excellent performance in many fields, especially in capacitors. Developing soft-chemistry synthesis methods is critically of importance, while the forming mechanism in this area is not clear. In this paper, we present a critical review of CNOs regarding the structure, especially interlayer spacing, and synthesis processes, elaborating the recent progress on soft-chemistry methods. Hansen solubility parameter theory is applied to predict and regulate the solubility of CNOs. This article would be inspirational and give new insights into understanding the formation and properties of CNOs.

The interaction of atoms and molecules with nanocapsules and hollow nanowires

Nanoporous membranes are widely used in various fields, such as gas separation, water purification, catalytic processes, and the use of batteries in electrodes. Nowadays, hollow carbon spheres or nanowires are attracting attention of researchers and experimenters due to high adjustability of their mechanical and chemical properties. This makes it possible, among other things, to more accurately adjust permeability of membranes created from this material for various atoms and molecules, which ensures a good degree of gas separation. The mathematical simulation of gas separation via nanocapsule and hollow nanowire porous membrane is performed. Research has shown that such membranes are able to separate He/\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\text{CH}_4$$\end{document}CH4/\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\text{H}_2$$\end{document}H2/\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\text{N}_2$$\end{document}N2 gas mixtures.

Experimental and theoretical investigations of the effect of heteroatom-doped carbon microsphere supports on the stability and storage capacity of nano-Co3O4 conversion anodes for application in lithium-ion batteries

Conversion-type anode materials have been intensely studied for application in Li-ion batteries (LIBs) due to their potentially higher capacities than current graphite-based anodes. This work reports the development of a high-capacity and stable anode from a nanocomposite of N and S co-doped carbon spheres (NSCSs) with Co₃O₄ (NSCS-Co₃O₄). A hydrothermal reaction of saccharose with l-cysteine was carried out, followed by its carbonization. CSs when used as supports for conversion-type materials provide efficient electron/ion transfer channels, enhancing the overall electrochemical performance of the electrodes. Additionally, the heteroatoms doped in a carbon matrix alter the electronic properties, often increasing the reactivity of the carbon surface, and they are reported to be effective for anchoring metal oxide nanoparticles. Consequently, the NSCS-Co₃O₄ nanocomposites developed in this work exhibit enhanced and stable reversible specific capacity over several cycles. Stable cycling behavior was observed at 1 A g^-1 with 1285 mA h g^-1 of specific capacity retained after 350 cycles along with more than 99% of coulombic efficiency. This material shows excellent rate capability with a specific capacity of 745 mA h g^-1 retained even at a high current density of 5 A g^-1. Detailed DFT-based calculations revealed the role of doped supports in controlling the volume expansion upon lithiation.

Rational Design of NiCoO2@SnO2 Heterostructure Attached on Amorphous Carbon Nanotubes with Improved Lithium Storage Properties

It still remains very challenging to design proper heterostructures to enhance the electrochemical performance of transition metal oxide-based anode materials for lithium-ion batteries. Here, we synthesized the NiCoO2 nanosheets@SnO2 layer heterostructure supported by amorphous carbon nanotubes (ACNTs) which is derived from polymeric nanotubes (PNTs) by a stepwise method. The inner SnO2 layer not only provides a considerable capacity contribution but also produces the extra Li2O to promote the charge process of NiCoO2 and thus results in a rising cycling performance. Combining with the contribution of ACNTs backbone and ultrathin NiCoO2 nanosheets, the specific capacities of these one-dimensional nanostructures show an interesting gradually increasing trend even after 100 cycles at 400 mA g(-1) with a final result of 1166 mAh g(-1). This approach can be an efficient general strategy for the preparation of mixed-metal-oxide one-dimensional nanostructures and this innovative design of hybrid electrode materials provides a promising approach for batteries with improved electrochemical performance.

High-rate and long-life of Li-ion batteries using reduced graphene oxide/Co3O4 as anode materials

A new one-step microwave method was designed for synthesis of rGO/Co₃O₄, and the Li-ion battery showed high capacity and long life.

Carbon nano-onions: large-scale preparation, functionalization and their application as anode material for rechargeable lithium ion batteries

Carbon nano-onions (CNOs) are one of the most promising anode materials for lithium ion batteries (LIBs) because of their outstanding physicochemical properties.

Core–shell-structured nickel ferrite/onion-like carbon nanocapsules: an anode material with enhanced electrochemical performance for lithium-ion batteries

Core–shell-structured nanocapsules consisting of a nickel ferrite (NiFe₂O₄) nanoparticle core encapsulated in an onion-like carbon (C) shell are prepared by a modified arc-discharge method followed by an air-annealing process.

Improved electrochemical performance of onion-like carbon coated magnetite nanocapsules as electromagnetic absorptive anode materials for lithium-ion batteries

The synthesis of magnetite (Fe₃O₄)@C nanocapsules with Fe₃O₄nanoparticles as the core and onion-like carbon as the shell has been reported.

A facile route for the synthesis of nanostructured oxides and hydroxides of cobalt using laser ablation synthesis in solution (LASIS)

We used a pulsed laser ablation synthesis in solution (LASIS) to produce cobalt oxide/hydroxide nanoparticles (NPs) with tailored size, morphology and structure at different laser fluences, wavelengths (532 and 1064 nm) and solvent conditions. Specifically, LASIS on bulk Co in the presence and absence of O2 in an aqueous solution initially produces cobalt monoxide (CoO) and single crystal β-cobalt hydroxide (β-Co(OH)2) nanoparticles (NPs) respectively that finally transform into cobaltosic oxide (Co3O4) through oxidation and/or thermal decomposition. Transmission electron microscopy (TEM) and scanning mobility particle sizer (SMPS) measurements on the final products reveal a bimodal size distribution of agglomerated NPs (for the 1064 and 532 nm laser) at low laser fluences, where the ablation mechanism is dominated by vaporization and normal boiling. In contrast, more efficient and predominant explosive boiling at higher laser fluences produces a mono-modal size distribution of spherically shaped primary NPs in agglomerates. Furthermore, higher absorbance of the 532 nm laser by solution-phase colloidal NPs re-ablates them into spherical shapes of larger size (∼13-22 nm) as compared to the ones from using 1064 nm LASIS (∼10-14 nm), while rendering 532 nm LASIS less productive than 1064 nm LASIS over an extended period of time. Finally, Co3O4 nanorods with enhanced localized surface plasmon resonance (LSPR) are synthesized at high pH (pH ≥ 13) and low laser fluence (<5 mJ cm(-2)) conditions. Such nanostructured materials are promising candidates as photocatalysts or additives in nanocomposite materials with enhanced light absorption properties.

Micro-/nanostructured Co3O4 anode with enhanced rate capability for lithium-ion batteries

Through a facile hydrothermal method with a special surfactant triethanolamine (TEA) followed by thermal treatment, monodispersed micro-/nanostructured Co3O4 powders with unique morphology (cube) have been synthesized successfully as anode material for Li-ion batteries (LIBs). The regular Co3O4 microcubes (∼2.37 μm in the average side length) consist of many irregular nanoparticles (20-200 nm in diameter, 30-40 nm in thickness) bonded to each other, which greatly inherit the morphology and size of the precursor CoCO3. The specific surface area of Co3O4 powders is about 5.10 m(2)·g(-1) by the Brunauer-Emmett-Teller (BET) method, and the average pore size is about 3.08 nm by the Barrett-Joyner-Halenda (BJH) method. In addition, the precursor is verified as a single-crystal, while the mesoporous cubic Co3O4 is a polycrystalline characteristic assembled by numerous single-crystal nanoparticles. More remarkable, the high performance of the micro-/nanostructured cubic Co3O4 powders has been obtained by the electrochemical measurements including high initial discharge capacities (1298 mAhg(-1) at 0.1 C and 1041 mAhg(-1) at 1 C), impressive rate capability, and excellent capacity retention (99.3%, 97.5%, 99.2%, and 89.9% of the first charge capacities after 60 cycles at 0.1 C, 0.2 C, 0.5 C, and 1 C, respectively).