Synthesis of NiO Nano Octahedron Aggregates as High-Performance Anode Materials for Lithium Ion Batteries

Simple Solution Plasma Synthesis of Ni@NiO as High-Performance Anode Material for Lithium-Ion Batteries Application

Pursuing of straightforward and cost-effective methods for synthesizing high-performance anode materials for lithium-ion batteries is a topic of significant interest. This study elucidates a one-step synthesis approach for a conversion composite using glow discharge in a nickel formate solution, yielding a composite precursor comprising metallic nickel, nickel hydroxide, and basic nickel salts. Subsequent annealing of the precursor facilitated the formation of the Ni@NiO composite, exhibiting exceptional electrochemical properties as anode material in Li-ion batteries: a capacity of approximately 1000 mAh g-1, cyclic stability exceeding 100 cycles, and favorable rate performance (200 mAh g-1 at 10 A g Collapse

Key Words

• Anode material
• Composite Ni@NiO
• Conversion metal oxide anodes
• Lithium-ion batteries
• One-step plasma solution synthesis

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Grants

• 20-53-04010 RFBR
• F21RM-104 RFBR

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Affiliation(s)

Evgenii Beletskii Institute of Chemistry, St. Petersburg University, St. Petersburg, Universitetskaya Emb.7/9, 199034, Russia
Mikhail Pinchuk Institute for Electrophysics and Electrical Power of the Russian Academy of Sciences, Dvortsovaya Naberezhnaya 18, St. Petersburg, 191186, Russia
Vadim Snetov Institute for Electrophysics and Electrical Power of the Russian Academy of Sciences, Dvortsovaya Naberezhnaya 18, St. Petersburg, 191186, Russia
Aleksandr Dyachenko Institute for Electrophysics and Electrical Power of the Russian Academy of Sciences, Dvortsovaya Naberezhnaya 18, St. Petersburg, 191186, Russia
Alexey Volkov Institute of Chemistry, St. Petersburg University, St. Petersburg, Universitetskaya Emb.7/9, 199034, Russia
Egor Savelev Institute of Chemistry, St. Petersburg University, St. Petersburg, Universitetskaya Emb.7/9, 199034, Russia
Valentin Romanovski Department of Materials Science and Engineering, University of Virginia, Charlottesville, VA, 22904, USA

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Collaborators Collapse

Single "Swiss-roll" microelectrode elucidates the critical role of iron substitution in conversion-type oxides

Advancing the lithium-ion battery technology requires the understanding of electrochemical processes in electrode materials with high resolution, accuracy, and sensitivity. However, most techniques today are limited by their inability to separate the complex signals from slurry-coated composite electrodes. Here, we use a three-dimensional "Swiss-roll" microtubular electrode that is incorporated into a micrometer-sized lithium battery. This on-chip platform combines various in situ characterization techniques and precisely probes the intrinsic electrochemical properties of each active material due to the removal of unnecessary binders and additives. As an example, it helps elucidate the critical role of Fe substitution in a conversion-type NiO electrode by monitoring the evolution of Fe₂O₃ and solid electrolyte interphase layer. The markedly enhanced electrode performances are therefore explained. Our approach exposes a hitherto unexplored route to tracking the phase, morphology, and electrochemical evolution of electrodes in real time, allowing us to reveal information that is not accessible with bulk-level characterization techniques.

Realizing High-Performance Lithium Storage by Fabricating FeTiO3 Nanoparticle-Impregnated Multichannel Carbon Nanofibers with Promoted Reaction Kinetics

In this paper, a free-standing film of ilmenite FeTiO₃ nanoparticle-impregnated porous multichannel N-doped carbon nanofibers (NF-FTO) is fabricated via electrospinning technology. The as-prepared NF-FTO film is highly flexible and can be tailored to a suitable size to assemble into lithium-ion batteries. The introduction of a conductive N-doped carbon matrix is conducive to the improvement of intrinsic electronic conductivity and the acceleration of Li⁺ diffusion kinetics. The construction of the porous structure and highly parallel channels facilitates the transfer of electrolyte to FTO particles through the pores and shortens the transport path of lithium ions. Thus, the self-supporting electrode yields an initial charge capacity of 718.5 mAh g^-1 at 50 mA g^-1, a high-rate performance of 410.4 mAh g^-1 at 3 A g^-1, and an outstanding cycling performance with no capacity decay after 1500 cycles at 3 A g^-1. By ex situ X-ray diffraction and transmission electron microscopy analysis, the reaction mechanism of NF-FTO is determined as a reversible conversion reaction. Furthermore, the assembled LiFePO₄/NF-FTO full cell delivers an initial discharge capacity of 521 mAh g^-1 and superb rate performance.

Closed-loop selective recycling process of spent LiNixCoyMn1-x-yO2 batteries by thermal-driven conversion

The consumption of lithium-ion batteries raises raw material demand for and the pressure on ecological sustainability. Metals can be recovered in shorter paths while considerably boosting material use, hence selective recycling of specific elements is becoming a hotspot. This paper proposes a thermally-driven closed-loop recycling process for scrap LiNi_1/3Co_1/3Mn_1/3O₂ cathodes, in which Li is efficiently extracted by water leaching. Then, by combining the leaching residue with Li₂CO₃, a solid-phase synthesis is carried out, with Li being targeted to heal into Ni-Co-Mn-O to construct the layered structure. The electrochemical performance of the resynthesized cathode material is comparable to that of the commercial LiNi_0.5Co_0.2Mn_0.3O₂ (NCM523) material. During the thermal-driven conversion, solid-state processes can be observed. To ensure charge conservation, Li⁺ in the unstable layered structure is released and mixed with SO₄^2- to produce Li₂SO₄, and lattice oxygen escapes and transforms with Ni²⁺ to generate NiO. For the resynthesized process, the spherical shape of Ni-Co-Mn-O is largely retained. Notably, sulfur is remained in the form of SO₄^2- throughout the closed-loop process and is therefore free of contamination. The thermal-driven conversion recycling process revealed in this study will encourage researchers to ensure more efforts in efficient and selective recovery for sustainable energy storage of rechargeable batteries.

Local Ordering of Molten Salts at NiO Crystal Interfaces Promotes High-Index Faceting

Given the strong influence of surface structure on the reactivity of heterogeneous catalysts, understanding the mechanisms that control crystal morphology is an important component of designing catalytic materials with targeted shape and functionality. Herein, we employ density functional theory to examine the impact of growth media on NiO crystal faceting in line with experimental findings, showing that molten-salt synthesis in alkali chlorides (KCl, LiCl, and NaCl) imposes shape selectivity on NiO particles. We find that the production of NiO octahedra is attributed to the dissociative adsorption of H2 O, whereas the formation of trapezohedral particles is associated with the control of the growth kinetics exerted by ordered salt structures on high-index facets. To our knowledge, this is the first observation that growth inhibition of metal-oxide facets occurs by a localized ordering of molten salts at the crystal-solvent interface. These findings provide new molecular-level insight on kinetics and thermodynamics of molten-salt synthesis as a predictive route to shape-engineer metal-oxide crystals.

Triggering the Reversible Reaction of V3+/V4+/V5+ in Na3V2(PO4)3 by Cr3+ Substitution

Sodium-ion batteries (SIBs) have grabbed worldwide attention as an alternative to lithium-ion batteries on account of the abundance and accessibility of the sodium element in nature. For the sake of meeting the requirements for various applications containing grid-scale energy storage system, electric vehicles, and so forth, a stable and high-voltage cathode is decisive to enhance the energy and power density of SIBs. In this research, sodium super ionic conductor structured Na₃V_1.5-xCr_0.5+x(PO₄)₃ with different V/Cr ratios to balance the V³⁺/V⁴⁺ and V⁴⁺/V⁵⁺ redox couples was investigated as the potential cathode for SIBs. Among these candidates, Na₃V_1.3Cr_0.7(PO₄)₃ manifested high energy density together with good cycling performance and rate capability. Combining the structural analysis and density functional theory calculation, the underlying mechanism of V³⁺ substitution by Cr³⁺ was uncovered, accounting for the improvement of electrochemical performance.

Ag3PO4/NiO Composites with Enhanced Photocatalytic Activity under Visible Light

Black NiO powders were prepared by a hydrothermal method. Moreover, the visible light-driven Ag3PO4/NiO photocatalyst composites were successfully synthesized by in situ precipitation method. These samples were structurally characterized by X-ray diffraction and Rietveld refinement. The strong interaction between the phases and the defects in the samples was affected by the formation of the composites, as identified by Fourier transform infrared spectroscopy and Raman spectroscopy. UV-vis diffuse reflectance spectroscopy exhibited enhanced light absorption for all Ag3PO4/NiO composites, suggesting the effective interaction between the phases. Moreover, field-emission scanning electron microscopy images revealed the presence of NiO microflowers composed of nanoflakes in contact with Ag3PO4 microparticles. The composite with 5% NiO presented enhanced photocatalytic efficiency in comparison with pure Ag3PO4, degrading 96% of rhodamine B (RhB) dye in just 15 min under visible light; however, the recycling experiments confirmed that the composite with 75% NiO showed superior stability. The recombination of the electron-hole pairs was considered for the measurement of the photoluminescence of the samples. These measurements were performed to evaluate the possible causes for the difference in the photocatalytic responses of the composites. From these experimental results, possible photocatalytic mechanisms for RhB degradation over Ag3PO4/NiO composites under visible-light irradiation were proposed.

Fabrication of 3D binder-free graphene NiO electrode for highly stable supercapattery

Electrochemical stability of energy storage devices is one of their major concerns. Polymeric binders are generally used to enhance the stability of the electrode, but the electrochemical performance of the device is compromised due to the poor conductivity of the binders. Herein, 3D binder-free electrode based on nickel oxide deposited on graphene (G-NiO) was fabricated by a simple two-step method. First, graphene was deposited on nickel foam via atmospheric pressure chemical vapour deposition followed by electrodeposition of NiO. The structural and morphological analyses of the fabricated G-NiO electrode were conducted through Raman spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and energy dispersive X-ray spectroscopy (EDS). XRD and Raman results confirmed the successful growth of high-quality graphene on nickel foam. FESEM images revealed the sheet and urchin-like morphology of the graphene and NiO, respectively. The electrochemical performance of the fabricated electrode was evaluated through cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) in aqueous solution at room temperature. The G-NiO binder-free electrode exhibited a specific capacity of ≈ 243 C g-1 at 3 mV s-1 in a three-electrode cell. A two-electrode configuration of G-NiO//activated charcoal was fabricated to form a hybrid device (supercapattery) that operated in a stable potential window of 1.4 V. The energy density and power density of the asymmetric device measured at a current density of 0.2 A g-1 were estimated to be 47.3 W h kg-1 and 140 W kg-1, respectively. Additionally, the fabricated supercapattery showed high cyclic stability with 98.7% retention of specific capacity after 5,000 cycles. Thus, the proposed fabrication technique is highly suitable for large scale production of highly stable and binder-free electrodes for electrochemical energy storage devices.

Facile fabrication of a NiO/Ag3PO4 Z-scheme photocatalyst with enhanced visible-light-driven photocatalytic activity

The photocatalytic performance of Z-scheme NiO/Ag/Ag₃PO₄ was evaluated by degrading organic pollutants under visible light.

Carboxyl functionalized carbon incorporation of stacked ultrathin NiO nanosheets: topological construction and superior lithium storage

Two-dimensional (2D) nanostructure engineering and surface modification with functional groups are of great importance to anode materials for rechargeable lithium-ion batteries. Herein, stacked NiO nanosheets@carbon (denoted as NiO@C) and 3 nm-ultrathin NiO nanosheets@functionalized carbon with surface functional groups NO3-, CO32-, OH-, and COOH- (denoted as NiO@FC) were prepared via a facile one-pot reaction and topotactic conversion. Specifically, NiO@FC exhibits excellent lithium storage performance: the capacity of NiO@FC is 489.2 mA h g-1, higher than that of NiO@C (1018.7 mA h g-1 at 0.2 A g-1), and maintains a capacity of 1133 mA h g-1 after 800 cycles, which exceed that of all previously reported NiO anodes. The enhanced lithium storage performance is attributed to the sufficient void space, which offers buffer space for volume change and speeds up the diffusion of Li+ ions. In addition, the surface functional groups were proved to not only hinder the agglomeration of nanosheets but also further donate active sites and improve storage capacity. These advantageous features achieved by designing such a stacked structure with functionalized carbon modification provide a promising strategy for the preparation of high-performance anode materials and other 2D functional materials.

Structural analysis of the initial lithiation of NiO thin film electrodes

Our results reveal that conversion reactions and structural changes in NiO thin film electrodes begin near the theoretical lithiation potential.

Hierarchical NiO nanobelt film array as an anode for lithium-ion batteries with enhanced electrochemical performance

In this study, an ultrathin 2-dimensional hierarchical nickel oxide nanobelt film array was successfully assembled and grown on a Ni substrate as a binder-free electrode material for lithium ion batteries.

The effect of the phase structure on physicochemical properties of TMO materials: a case of spinel to bunsenite

It is worthwhile to comprehensively investigate the relationship between different phase structures and physicochemical properties of TMO materials.

Synthesis of uniform porous NiO nanotetrahedra and their excellent gas-sensing performance toward formaldehyde

Porous NiO nanotetrahedrons and elongated irregular nanoparticles were synthesized, exhibiting superior gas-sensing behavior toward formaldehyde with high gas sensitivity and stability.