• Journal of the Korean Electrochemical Society
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• v.8 no.1
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• pp.42-46
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• 2005

It has been known that the synthesis of the cathode materials for the lithium rechargeable batteries by the sol-gel process has many advantages over the conventional solid-state method. It has been, however, a continuing issue that new additional steps should be introduced to commercialize this process. In this work, spray drying was introduced to the existing sol-gel process as a continuous mass production method of the pre-heat treatment precursor materials. The precursors of $LiCoO_2$ and $LiNi_{0.8}Co_{0.2}O_2$ were continuously produced through spray drying from the solution containing stoichiometric amount of lithium, cobalt, and nickel sources as well as a chelating agent. The process variables, such as pH of the starting solution, spray drying conditions, and calcination conditions were optimized. The XRD pattern for the synthesized material indicated a good crystallinity with a layered structure.

• 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.

• Korean Chemical Engineering Research
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• v.49 no.5
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• pp.554-559
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• 2011

To improve the safety and electrode characteristics of lithium metal anode, physically coated electrodes on lithium metal surface by three kinds of carbon are prepared and their charge-discharge performances are investigated by adopting the C-Li electrodes as the anode of rechargeable lithium batteries. The lithium anode coated by the carbon powder with smaller particle size and higher surface area, which has higher packing density and lower surface roughness, shows better performance in charge-discharge characteristics. The carbon coating on lithium surface can be more effective in small-sized cells.

• Carbon letters
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• v.28
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• pp.1-8
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• 2018

Graphene is a single atomic layer of carbon atoms, and has exceptional electrical, mechanical, and optical characteristics. It has been broadly utilized in the fields of material science, physics, chemistry, device fabrication, information, and biology. In this review paper, we briefly investigate the ideas, structure, characteristics, and fabrication techniques for graphene applications in lithium ion batteries (LIBs). In LIBs, a constant three-dimensional (3D) conductive system can adequately enhance the transportation of electrons and ions of the electrode material. The use of 3D graphene and graphene-expansion electrode materials can significantly upgrade LIBs characteristics to give higher electric conductivity, greater capacity, and good stability. This review demonstrates several recent advances in graphene-containing LIB electrode materials, and addresses probable trends into the future.

• 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 Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.326-332
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• 2018

Korea faces major changes in energy policy, which include eco-friendly and zero-nuclear power. On the other hand, there are very few policies for the waste-management of mid- to large-sized lithium-ion batteries, such as electric car batteries and energy storage systems, which are expected to increase explosively due to such energy policy changes. Therefore, this study estimated the amount of mid- to large-sized lithium ion batteries waste and performed economics analysis of a middle and large sized secondary battery recycling project. Based on the results, a policy alternative for the revitalization of the related lithium-ion battery recycling industry is suggested. As a result, the B / C ratio of a domestic mid - to large - sized lithium ion battery recycling project is 1.06, in which the benefit is higher than the cost, so the business is economic feasible. Although the recycling project's economic efficiency is high, the recycling industry has not been activated in Korea because the domestic demand for rechargeable batteries recycling is very low. To solve this problem, this study proposes a plan to activate the industry by adding lithium secondary batteries to the EPR (Extended Producer Responsibility) items.

• Journal of Electrochemical Science and Technology
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• v.10 no.2
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• pp.131-138
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• 2019

To improve the performance of Si anodes in advanced Li-ion batteries, the design of the electrode plays a critical role, especially due to the large volumetric expansion in the Si anode during Li insertion. In our study, we used a simple fabrication method to prepare Si-based electrodes by grafting polyacrylic acid (PAA) to a carboxymethyl cellulose (CMC) binder (CMC-g-PAA). The procedure consists of first mixing nano-sized Si and the binders (CMC and PAA), and then coating the slurry on a Cu foil. The carbon network was formed via carbonization of the binders i.e., by a simple heat treatment of the electrode. The carbon network in the electrode is mechanically and electrically robust, which leads to higher electrical conductivity and better mechanical property. This explains its long cycle performance without the addition of a conducting agent (for example, carbon). Therefore, the partially carbonized CMC-g-PAA binder presented in this study represents a new feasible approach to produce Si anodes for use in advanced Li-ion batteries.

• Korean Journal of Materials Research
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• v.8 no.4
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• pp.323-327
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• 1998

All solid state lithium based rechargeable batteries were fabricated in a cell structure of Li/PEO-$LiCIO_4$-PC /$LIMn_2O_4$$LIMn_2O_4$ thin films were prepared by RF magnetron sputtering and the spinel structure could be obtained by Rapid Thermal Annealing (RT A) process at the temperature of around 750$750^{\circ}C$ . Room temperature cycling of this cell showed a nearly constant cell potential of 4 V( us. Li) and good reversibility.

• Korean Journal of Materials Research
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• v.22 no.12
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• pp.717-721
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• 2012

Manganese dioxide ($MnO_2$) is one of the most important cathode materials used in both aqueous and non-aqueous batteries. The $MnO_2$ polymorph that is used for lithium primary batteries is synthesized either by electrolytic (EMD-$MnO_2$) or chemical methods (CMD-$MnO_2$). Commonly, electrolytic manganese dioxide (EMD) is used as a cathode mixture material for dry-cell batteries, such as a alkaline batteries, zinc-carbon batteries, rechargeable alkaline batteries, etc. The characteristics of lithium/manganese-dioxide primary cells fabricated with EMD-$MnO_2$ powders as cathode were compared as a function of the parameters of a manufacturing process. The flexible primary cells were prepared with EMD-$MnO_2$, active carbon, and poly vinylidene fluoride (PVDF) binder (10 wt.%) coated on an Al foil substrate. A cathode sheet with micro-porous showed a higher discharge capacity than a cathode sheet compacted by a press process. As the amount of EMD-$MnO_2$ increased, the electrical conductivity decreased and the electrical capacity increased. The cell subjected to heat-treatment at $200^{\circ}C$ for 1 hr showed a high discharge capacity. The flexible primary cell made using the optimum conditions showed a capacity and an average voltage of 220 mAh/g and 2.8 V, respectively, at $437.5{\mu}A$.

• Journal of the Korean Society of Safety
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• v.33 no.1
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• pp.22-27
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• 2018

Many electronic devices are powered by various rechargeable batteries such as lithium-ion recently, and occasionally the batteries undergo thermal runaway and cause fire, explosion, and other hazards. If a battery fire should occur in an electronic device of vehicle and aircraft cabin, it is important to quickly extinguish the fire and cool the batteries to minimize safety risks. Attempts to minimize these risks have been carried out by many researchers but the results have been still unsatisfied. Because most rechargeable batteries are operated on the ion state during charge and discharge of electricity and the combustion of ion state has big difference with normal combustion. Here we focused on the effect of ions including an electron during combustion process. The effects of an ionized fuel on the flame stability and the combustion products were experimentally investigated in the propane jet diffusion flames. The burner used in this experiment consisted of 7.5 mm diameter tube for fuel and the propane was ionized with th ionizer (SUNJE, SPN-11). The results show that toe overall flame stability and shape such as flame length has no significant difference even in the higher ion concentration. However the fuel ionization affects to the pollutant emissions such as NOx and soot. NOx and CO emissions measured in post flame region decreased by fuel ionization, especially high fuel velocity, i.e. high ion density. TGA analysis and morphology of soot by TEM indicates that the fuel ionization makes soot to be matured.