• Journal of Electrochemical Science and Technology
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• v.7 no.3
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• pp.206-213
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• 2016

Transition metal oxide-based electrodes for lithium ion batteries have recently attracted much attention because of their high theoretical capacity. Here we report the electrochemical behavior of cobalt oxide nanorods as anodes, prepared by a template-free, one-step electrochemical deposition of cobalt nanorods, followed by an oxidation process. The as-deposited cobalt has a slightly convex columnar structure, and controlled thermal oxidation produces cobalt oxides of different Co/O ratios, while the original shape is largely preserved. As an anode in a rechargeable lithium battery, the Co/O ratio has a strong effect on initial capacity and cycling stability. In particular, the one-dimensional Co@Co_xO_y core shell structure obtained from a mild heat-treatment results in superior cycling stability.

• Journal of the Korean Electrochemical Society
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• v.2 no.1
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• pp.46-49
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• 1999

Lithium cobalt oxide cathode for thin-film rechargeable lithium batteries were fablicated by electron-beam evaporation. Annealed lithium cobalt oxide, which was deposited on to stainless steel substrate, showed well-developed (003) planes of the hexagonal structure and potential plateau at $\~3.9 V$. Lithium cobalt oxide thin films had the stoichiometric Li/co ratio at high deposition rates and exhibited high discharge capacity at $15{\AA}/s$. As the annealing temperature increased, discharge capacity increased with maximum value at $700^{\circ}C$, but showed low capacity as a result of reaction with substrate above $700^{\circ}C$. Unuiformity of the lithium and cobalt in the depth profile gave initial capacity loss with charge/discharge performance.

• Journal of the Korean Electrochemical Society
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• v.13 no.4
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• pp.290-294
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• 2010

We performed a density functional theory study to investigate the intercalation voltage and lithium ion conduction in lithium cobalt oxide for lithium ion battery as a function of the lithium concentration. There were two methods for the intercalation of lithium ions; the intercalation of a lithium ion at a time in the individual layer and the intercalation of lithium ions in all the sites of one layer after all the sites of another layer. The average intercalation voltage was the same value, 3.48 V. However, we found the former method was more favorable than the latter method. The lattice parameter c was increased as the increase of the lithium concentration in the range of x < 0.25 while it was decreased as increase of the lithium concentration in the range of x > 0.25. The energy barrier for the conduction of lithium ion in lithium cobalt oxide was increased as the lithium concentration was increased. We demonstrated that the decrease of the intercalation voltage and increase of the energy barrier as the increase of the lithium concentration caused lower output voltage during the discharge of the lithium ion battery.

• Resources Recycling
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• v.19 no.6
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• pp.51-60
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• 2010

A study on the recovery of cobalt and lithium from Lithium Ion Battery(LIB) scraps has been carried out by a physical treatment - leaching - solvent extraction process. The cathode scraps of LIB in production were used as a material of this experiment. The best condition for recovering cobalt from the anode scraps was acquired in each process. The cathode scraps are dissolved in 2M sulfuric acid solution with hydrogen peroxide at $95^{\circ}C$, 700 rpm. The cobalt is concentrated from the leaching solution by means of a solvent extraction circuit with bis(2-ethylhexyl) phosphoric acid(D2EHPA) and PC88A in kerosene, and then cobalt and lithium are recovered as cobalt hydroxide and lithium carbonate by precipitation technology. The purity of cobalt oxide powder was over 99.98% and the average particle size after milling was about 10 lim. The over all recoveries are over 95% for cobalt and lithium. The pilot test of mechanical separation was carried out for the recovery of cobalt from the scraps. The $Co_3O_4$ powder was made by the heat treatment of $Co(OH)_2$ and the average particle size was about 10 ${\mu}m$ after grinding. The recovery was over 99% for cobalt and lithium each other and the purity of cobalt oxide was over 99.98%.

• Nuclear Engineering and Technology
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• v.53 no.8
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• pp.2570-2575
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• 2021

The exchange behaviors of hydrogen isotopes between protonated lithium metal compounds and deuterated water or tritiated water were investigated. The various protonated lithium metal compounds were prepared by acid treatment of lithium metal compounds with different crystal structures and metal compositions. The protonated lithium metal compounds could more effectively reduce the deuterium concentration in water compared with the corresponding pristine lithium metal compounds. The H⁺ in the protonated lithium metal compounds was speculated to be more readily exchangeable with hydrons in the aqueous solution compared with Li⁺ in the pristine lithium metal compounds, and the exchanged heavier isotopes were speculated to be more stably retained in the crystal structure compared with the light protons. When the tritiated water (157.7 kBq/kg) was reacted with the protonated lithium metal compounds, the protonated lithium manganese nickel cobalt oxide was found to adsorb and retain twice as much tritium (163.9 Bq/g) as the protonated lithium manganese oxide (69.9 Bq/g) and the protonated lithium cobalt oxide (75.1 Bq/g) in the equilibrium state.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.365.1-365.1
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• 2014

Cobalt oxide has excellent various properties such as high catalytic activity, antiferromagnetism, and electrochromism. So cobalt oxides offer a great potential for their applications in the various areas such as optical gas sensor, catalysts for oxidation reaction, electrochromic devices, high temperature solar selective absorbers, magnetic materials, pigment for glasses and ceramics, and negative electrodes for lithium-ion batteries. We have synthesized novel cobalt complexes by simple reaction of cobalt bistrimethylsilylamide as a starting material with a lot of conventional ligands as potential cobalt oxide precursors. The studies include the facile preparation, structural characterization, and spectroscopic analysis of the new precursors. We are making efforts to grow cobalt oxide thin films using cobalt complexes newly synthesized in this study using deposition techniques.

• Journal of the Korean Ceramic Society
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• v.48 no.6
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• pp.636-640
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• 2011

Nano-sized cobalt (II) oxide nanoparticles with a high crystallinity were synthesized using thermolysis of a $Co^{2+}$-oleate precursor at 310$^{\circ}C$. The phase and morphology of as-prepared cobalt oxide nanoparticles were characterized using X-ray diffraction, high-resolution transmission electron microscopy, and Brunauer-Emmett-Teller surface area measurements. The cobalt oxide nanoparticles were found to be spherical nanoclusters with an average diameter of approximately 200 nm, consisting of tiny nanocrystals (10-20 nm). Furthermore, the Li electroactivites of the cobalt oxide nanoparticles were investigated using cyclic voltammetry and galvanostatic cycling. The cobalt oxide nanoparticles could deliver high capacities over 420 mA h $g^{-1}$ at a C/5 current rate.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.11a
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• pp.25-28
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• 1998

Lithiated cobalt and nickel oxides are becoming very attractive as active cathode materials for secondary lithium ion secondary battery. $LiCoO_2$ is easily synthesized from lithium cobalt salts, but has a relatively high oxidizing potential on charge. LiNiOz is synthesized by a more complex procedure and its nonstoichiometry significantly degraded the charge-discharge characteristics. But $LiNiO_2$ has a lower charge potential which increases the system stability. Lithiated cobalt and nickel oxides are iso-structure which make the preparation of solid solutions of $LiNi_{1-x}Co_xO_2$ for O$LiCoO_2 and LiNiO_2$ electrode. The aim of the presentb paper is to study the electrochemical behaviour, as weU as the possibilities for practical application of layered Iithiated nickel oxide stabilized by $Co^{3+}$ substitution as active cathode materials in lithium ion secondary battery.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.5
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• pp.335-340
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• 2018

Transition metal oxide materials have attracted widespread attention as Li-ion battery electrode materials owing to their high theoretical capacity and good Li storage capability, in addition to various nanostructured materials. Here, we fabricated a CoO Li-ion battery in which Co nanoparticles (NPs) are deposited into a current collector through electrophoretic deposition (EPD) without binding and conductive agents, enabling us to focus on the intrinsic electrochemical properties of CoO during the conversion reaction. Through optimized Co NP synthesis and electrophoretic deposition (EPD), CoO Li-ion battery with 630 mAh/g was fabricated with high cycle stability, which can potentially be used as a test platform for a fundamental understanding of conversion reaction.

• Journal of Powder Materials
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• v.18 no.3
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• pp.277-282
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• 2011

[ $LiCoO_2$ ] a cathode material for lithium rechargeable batteries, was prepared using recycled $Co_3O_4$. First, the cobalt hydroxide powders were separated from waste WC-Co hard metal with acid-base chemical treatment, and then the impurities were eliminated by centrifuge method. Subsequently, $Co_3O_4$ powders were prepared by thermal treatment of resulting $Co(OH)_2$. By adding a certain amount of $Li_2CO_3$ and $LiOH{\cdot}H_2O$, the $LiCoO_2$ was obtained by sintering for 10 h in air at $800^{\circ}C$. The synthesized $LiCoO_2$ particles were characterized by X-ray diffraction (XRD) and Scanning Electron Microscope (SEM) analysis.