• Journal of Powder Materials
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• v.21 no.4
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• pp.286-293
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• 2014

The electrochemical properties of cells assembled with the $LiNiO_2$ (LNO) recycled from cathode materials of waste lithium secondary batteries ($Li[Ni,Co,Mn]O_2$), were evaluated in this study. The leaching, neutralization and solvent extraction process were applied to produce high-purity $NiSO_4$ solution from waste lithium secondary batteries. High-purity NiO powder was then fabricated by the heat-treatment and mixing of the $NiSO_4$ solution and $H_2C_2O_4$. Finally, $LiNiO_2$ as a cathode material for lithium ion secondary batteries was synthesized by heat treatment and mixing of the NiO and $Li_2CO_3$ powders. We assembled the cells using the $LiNiO_2$ powders and evaluated the electrochemical properties. Subsequently, we evaluated the recycling possibility of the cathode materials for waste lithium secondary battery using the processes applied in this work.

• Journal of Electrochemical Science and Technology
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• v.15 no.1
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• pp.161-167
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• 2024

Despite the important role of manganese (Mn) in cobalt-free, Ni-rich cathode materials, existing reports on the effects of Mn as a substitute for cobalt are not consistent. In this work, we analyzed the performance of cathodes comprised of Li(Ni_1-xMn_x)O₂ (LNMO). Both beneficial and detrimental results occurred as a result of the Mn substitution. We found that a complex interplay of effects (Li/Ni mixing driven by magnetic frustration, grain growth suppression, and retarded lithium insertion/extraction kinetics) influenced the performance and was intimately related to calcination temperature. This indicates the importance of establishing an optimal reaction temperature for the development of high-performance LNMO.

• Journal of Power System Engineering
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• v.17 no.1
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• pp.110-115
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• 2013

The electrochemical performance and microstructure of Al-Si, Al-Si/C was investigated as anode for lithium ion battery. The Al-Si nano composite with 5 : 1 at% ratio was prepared by arc-discharge nano powder process. However, some of problem is occurred, when Al nano composite was synthesized by this manufacturing. The oxidation film is generated around Al-Si particles for passivating processing in the manufacture. The oxidation film interrupts electrical chemistry reaction during lithium ion insertion/extraction for charge and discharge. Because of the existence the oxidation film, Al-Si first cycle capacity is very lower than other examples. Therefore, carbon synthsized by glucose ($C_6H_{12}O_6$) was conducted to remove the oxidation film covered on the composite. The results showed that the first discharge cycle capacity of Al-Si/C is improved to 113mAh/g comparing with Al-Si (18.6mAh/g). Furthermore, XRD data and TEM images indicate that $Al_4C_3$ crystalline exist in Al-Si/C composite. In addition the Si-Al anode material, in which silicon is more contained was tested by same method as above, it was investigated to check the anode capacity and morphology properties in accordance with changing content of silicon, Si-Al anode has much higher initial discharge capacity(about 500mAh/g) than anode materials based on Aluminum as well as the morphology properties is also very different with the anode based Aluminum.

• Resources Recycling
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• v.21 no.6
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• pp.58-64
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• 2012

A study on the solvent extraction for the separation and recovery of Ni and Li from the leaching solution of active cathode materials of Li-ion batteries was investigated using PC88A(2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester). The experimental parameters, such as the pH of the solution, concentration of extractant and phase ratio were observed. Experimental results showed that the extraction percent of Ni and Li and separation factor of Ni/Li were increased with increasing the equilibrium pH. More than 99.4% of Ni and 28.7% of Li were extracted in eq. pH 8.5 by 25% PC88A and the separation factor of Ni/Li was 411.6. From the analysis of McCabe-Thiele diagram, 99% of Ni was extracted by three extraction stages at phase ratio(A/O) of 1.5. Stripping of Ni and Li from the loaded organic phases can be accomplished by sulfuric acid as a stripping reagent and 50-60g/L of $H_2SO_4$ was effective for the stripping of Ni.

• YAKHAK HOEJI
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• v.26 no.1
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• pp.25-27
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• 1982

We had reported that s-triazine can readily be converted into the corresponding 5-substituted pyrimide. In order to develop new synthetic method of 5-fluorouracil, we tried to replace eliminating fragment, 1, 3-dimethylurea, by fluoroacetamide, which was expected to undergo nucleophilic attack by proton extraction of both .alpha.-hydrogen and aminohydrogen by lithium diisopropylamide (LDA). We found that 5-fluorouracil could be transformed from s-triazine under strong base condition like LDA as well as other 5-substituted pyrimidines.

• Journal of the Mineralogical Society of Korea
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• v.25 no.2
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• pp.117-122
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• 2012

The leaching of Li from fly ashes was studied. The fly ash produced from the Taean electric power plant of the Korea Western Power Co., Ltd. was used for this study. The Li leaching was observed according to the changes in solid:solution ratio, solution types (seawater or deionized water), and the $CO_2$ condition in the atmosphere. The results showed that the Li concentrations in the solution increased continuously as the solid:solution ratio increased. The Li leaching per unit mass of fly ash was greater when the deionized water was used for the experiment and when the $CO_2$ dissolution is limited during the reaction because the precipitation of $CaCO_3$ is suppressed under those conditions. At high solid:solution ratio, $Mg^{2+}$, the ion preventing the Li extraction from seawater by adsorption, was effectively removed from the seawater.

• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2304-2308
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• 2010

A $LiNi_{0.8}Co_{0.15}Al_{0.05}O_2$ (LNCAO/C) active material composite cathode was coated with carbon. The conductive carbon coating was obtained by addition of surfactant during synthesis. The addition of surfactant led to the formation of an amorphous carbon coating layer on the pristine LNCAO surface. The layer of carbon coating was clearly detected by FE-TEM analysis. In electrochemical performance, although the LNCAO/C showed similar capacity at low C-rate conditions, the rate capability was improved by the form of the carbon coating at high current discharge state. After 40 cycles of charge-discharge processes, the capacity retention of LNCAO/C was better than that of LNCAO. The carbon coating is effectively protected the surface structure of the pristine LNCAO during Li insertion-extraction.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.6
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• pp.770-778
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• 1996

A rapid and economical method of simultaneous extraction of DNA and RNA from seaweeds has been developed by the use of lithium chloride. Lithium chloride facilitates the softening of cell walls resulting in a decrease in both compressive and tensile modulus of elasticity. The DNA was characterized by high molecular weight larger than 27 kb and a relative lack of carbohydrate and protein contamination. The DNA and RNA extracted by the method from many seaweeds were of sufficient quality to be used as a template for per amplification with a plant intergenic gene primer set, for RAPD analysis with arbitrary primers, and for differential display with arbitrary primers in the morphologically distinct regions of the matured Porphyra thallus. The cDNA polymorphism indicated that the reproductive tissue types (male, female, patch) had a relatively high degree of similarity; the vegetative tissue types (dividing, non-dividing) also showed a similar pattern with respect to each other. Holdfast tissue had very low similarity with the other tissues, but appeared most similar to vegetative non-dividing tissue type.

• Journal of Power Electronics
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• v.13 no.3
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• pp.429-436
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• 2013

Online simulations are utilized to reduce time and cost in the development and performance optimization of plug-in hybrid electric vehicle (PHEV) and electric vehicles (EV) systems. One of the most important factors in an online simulation is the accuracy of the model. In particular, a model of a battery should accurately reflect the properties of an actual battery. However, precise dynamic modeling of high-capacity battery systems, which significantly affects the performance of a PHEV, is difficult because of its nonlinear electrochemical characteristics. In this study, a dynamic model of a high-capacity battery cell for a PHEV is developed through the extraction of the equivalent impedance parameters using electrochemical impedance spectroscopy (EIS). Based on the extracted parameters, a battery cell model is implemented using MATLAB/Simulink, and charging/discharging profiles are executed for comparative verification. Based on the obtained results, the model is optimized for a high-capacity battery cell for a PHEV. The simulation results show good agreement with the experimental results, thereby validating the developed model and verifying its accuracy.

• Journal of Powder Materials
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• v.29 no.3
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• pp.252-261
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• 2022

Cobalt is a vital metal in the modern society because of its applications in lithium-ion batteries, super alloys, hard metals, and catalysts. Further, cobalt is a representative rare metal and is the 30th most abundant element in the Earth's crust. This study reviews the current status of cobalt extraction and recycling processes, along with the trends in its production amount and use. Although cobalt occurs in a wide range of minerals, such as oxides and sulfides of copper and nickel ores, the amounts of cobalt in the minerals are too low to be extracted economically. The Democratic Republic of Congo (DRC) leads cobalt mining, and accounts for 68.9 % of the global cobalt reserves (142,000 tons in 2020). Cobalt is mainly extracted from copper-cobalt and nickel-cobalt concentrates and is occasionally extracted directly from the ore itself by hydro-, pyro-, and electro-metallurgical processes. These smelting methods are essential for developing new recycling processes to extract cobalt from secondary resources. Cobalt is mainly recycled from lithium-ion batteries, spent catalysts, and cobalt alloys. The recycling methods for cobalt also depend on the type of secondary cobalt resource. Major recycling methods from secondary resources are applied in pyro- and hydrometallurgical processes.