CoFe2O4 and NiFe2O4 synthesized by sol–gel procedures for their use as anode materials for Li ion batteries (original) (raw)
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Nanomaterials and Nanotechnology
The searches for advanced battery materials are endless. Ferrites have drawn much attention as a potential anode material in Li-ion battery. Nanocrystalline transition metal ferrite MFe2O4 (M = Ni, Co and Cu) thin films were deposited by spray pyrolysis technique over antimony doped tin oxide substrate. The phase and surface morphology were studied by X-ray diffraction and scanning electron microscope measurements, respectively. Magnetic property, film thickness and electrochemical performance of the materials are studied. The result shows that the films are of single phase, with cubic spinel structure for NiFe2O4 and CoFe2O4 and tetragonal structure for CuFe2O4. Magnetization studies reveal that the films are ferrimagnetic in nature. Electrochemical measurement reveals NiFe2O4 and CuFe2O4 are having good recyclable nature, which can be used as potential anode material for Li-ion batteries.
Electrochemical synthesis of nanocrystalline CoFe2O4 thin films and their characterization
Ceramics International, 2002
Nanocrystalline nickel-zinc ferrites Ni 0.5 Zn 0.5 Fe 2 O 4 thin films have been synthesized via the electrodeposition-anodization from the aqueous sulfate bath. The electrodeposited (Ni-Zn)Fe 2 alloy was anodized in aqueous 1 M KOH solution to form the corresponding hydroxides which annealed at different temperatures ranging from 800 to 1000 • C for various periods from 1 to 4 h, to get the required ferrite. SEM micrograph of the formed ferrite particles, annealed at 1000 • C for 4 h appeared as the octahedral-like structure. A good saturation magnetization of 28.2 emu/g was achieved for Ni 0.5 Zn 0.5 Fe 2 O 4 thin film produced after the aforementioned conditions. The kinetic studies of the crystallization of Ni 0.5 Zn 0.5 Fe 2 O 4 films appeared to be first-order reaction and the activation energy was found to be 10.5 k Joule/mole.
Nickel ferrite (NiFe 2 O 4) 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 NiFe 2 O 4 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 Crate), the synthesized NiFe 2 O 4 electrode provided a stable reversible capacity of 786 mAh g −1 with a capacity retention greater than 85%. The NiFe 2 O 4 electrode achieved a specific capacity of 365 mAh g −1 when cycled at a current density of 10 A g −1 (about a 10 Crate). At such a high current density, this is an outstanding capacity for NiFe 2 O 4 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 NiFe 2 O 4 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.
Cognizance Journal of Multidisciplinary Studies (CJMS), 2024
Research has been conducted in the pursuit of developing the performance of batteries. The increasing demand for electronic devices and electric vehicles has driven the development of high-performance lithium-ion batteries (LIBs). Among the various anode materials, α-Fe2O3 has attracted significant attention due to its high theoretical specific capacity of 1007 mAh/g. However, its low conductivity and poor rate capability limit its practical application. To address these issues, this study investigates the addition of nickel (Ni) into α-Fe2O3 through a co-precipitation method. The synthesized materials were characterized using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Scanning Electron Microscopy with Energy-Dispersive X-ray spectroscopy (SEM-EDX). The electrochemical performance was evaluated using an LCR meter and charge-discharge cycling. The results showed the addition of Ni improved the conductivity of the α-Fe2O3 material. The optimal Ni content was found as much as 18×10-4 mol which exhibits the highest conductivity and specific capacity. The synthesized α-Fe1.965Ni0.035O3 material demonstrated a specific charging capacity of 1.8433 mAh/g and a specific discharging capacity of 1.8388 mAh/g. These findings suggest that Ni-doped α-Fe2O3 has the potential to be a promising anode material for high-performance lithium-ion batteries (LIBs).
Nanotechnology, 2012
Uniform size cobalt ferrite nanoparticles have been synthesized in one step using an electrochemical technique. Synthesis parameters such as the current density, temperature and stirring were optimized to produce pure cobalt ferrite. The nanoparticles have been investigated by means of magnetic measurements, Mössbauer spectroscopy, x-ray powder diffraction and transmission electron microscopy. The average size of the electrosynthesized samples was controlled by the synthesis parameters and this showed a rather narrow size distribution. The x-ray analysis shows that the CoFe 2 O 4 obtained presents a totally inverse spinel structure. The magnetic properties of the stoichiometric nanoparticles show ferromagnetic behavior at room temperature with a coercivity up to 6386 Oe and a saturation magnetization of 85 emu g −1 .
Cyclic Voltammetry, Impedance and Thermal Properties of CoFe2O4 Obtained from Waste Li-Ion Batteries
Materials Today: Proceedings, 2018
In the present study, CoFe 2 O 4 nanocrystals were synthesized from waste lithium ion battery powder using citric acid as ecofriendly material by hydrothermal method. The prepared materials were characterized by X-ray powder diffraction (XRD) to study particle size and crystallinity, the morphology of the nano composite are analysed by using Scanning Electron Microscopy (SEM), functional group were observed using Fourier Transform Infrared Spectrometer (FTIR). The thermal properties of CoFe 2 O 4 nanocrystals were analysed using Thermo Gravimetric Analysis (TGA), Differential Scanning Calometry (DSC) and Differential Thermal Analysis. The synthesized nano particle was studied for the electrochemical studies such as Cyclic Voltammetry (CV), electrochemical impedance spectra, capacitance and electron transfer resistance.
Journal of Solid State Electrochemistry, 2008
CuFe 2 O 4 with a tetragonally distorted spinel structure has been prepared by the thermal decomposition of a citrate precursor. The copper-iron mixed organic salt was precipitated by either water evaporation or ethanol dehydration. The level of impurities of the final products depended on the precursor precipitation route and annealing temperature. EDH(800) material performed capacity values of 520 mAh/g after 50 cycles. Electron microscopy evidenced that the extrusion of copper yielded both transition metals separately at the end of discharge.