• Journal of the Korean Society of Visualization
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• v.21 no.2
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• pp.34-45
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• 2023

When lithium-ion batteries operate out of the proper temperature range, their performance can be significantly degraded and safety issues such as thermal runaway can occur. Therefore, battery thermal management systems are widely researched to maintain the temperature of Li-ion battery cells within the proper temperature range during the charging and discharging process. This study investigates the cooling performance and isothermal maintenance of cooling materials by measuring the surface temperature of a battery cell with or without cooling materials, such as silicone oil, thermal adhesive, and phase change materials during discharge process of battery by the experimental and numerical analysis. As a result of the experiment, the battery pack filled with phase change material showed a temperature reduction of 47.4 ℃ compared to the case of natural convection. It proves the advanced utility of the cooling unit using phase change material that is suitable for use in battery thermal management systems.

• Journal of Electrochemical Science and Technology
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• v.11 no.3
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• pp.195-219
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• 2020

Today, rechargeable lithium-ion batteries are an essential portion of modern daily life. As a promising alternative to traditional energy storage systems, they possess various advantages. This review attempts to provide the reader with an indepth understanding of the working mechanisms, current technological progress, and scientific challenges for a wide variety of lithium-ion battery (LIB) electrode nanomaterials. Electrochemical thermodynamics and kinetics are the two main perspectives underlying our introduction, which aims to provide an informative foundation for the rational design of electrode materials. Moreover, both anode and cathode materials are clarified into several types, using some specific examples to demonstrate both their advantages and shortcomings, and some improvements are suggested as well. In addition, we summarize some recent research progress in the rational design and synthesis of nanostructured anode and cathode materials, together with their corresponding electrochemical performances. Based on all these discussions, potential directions for further development of LIBs are summarized and presented.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.167-167
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• 2014

Graphite is used as a negative electrode active material of Lithium ion capacitor (LIC). At the cathod, electrostatic reaction of EDLC is a very high reaction rate compared to a oxidaion reduction reaction. When the graphite was expanded that the length between the sheet, the intercalation of lithium ions is smoothed. And thus, the power density increases. By measuring the XRD, it was confirmed that the increase in interlayer spacing of graphite. And by measuring an electrochemical reactionin Lithium Ion Battery (LIB), it was confirmed the tendency of power density is improved.

• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.733-741
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• 2018

Capacity estimation is indispensable to ensure the safety and reliability of lithium-ion batteries in electric vehicles (EVs). Therefore it's quite necessary to develop an effective on-board capacity estimation technique. Based on experiment, it's found constant current charge time (CCCT) and the capacity have a strong linear correlation when the capacity is more than 80% of its rated value, during which the battery is considered healthy. Thus this paper employs CCCT as the health indicator for on-board capacity estimation by means of relevance vector machine (RVM). As the ambient temperature (AT) dramatically influences the capacity fading, it is added to RVM input to improve the estimation accuracy. The estimations are compared with that via back-propagation neural network (BPNN). The experiments demonstrate that CCCT with AT is highly qualified for on-board capacity estimation of lithium-ion batteries via RVM as the results are more precise and reliable than that calculated by BPNN.

• Journal of the Korean Chemical Society
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• v.64 no.3
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• pp.153-158
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• 2020

With the recent popularity of mobile devices, the demand for lithium-ion batteries is increasing. In this study, the surface treatment process for the development of the Al (aluminum) lead tab for positive electrode, a key component of the pouch-type lithium-ion battery, was investigated. Anodizing and sealing processes were tested as surface treatment techniques. It was found that only a sealing process is needed to obtain sufficient adhesive strength. In the present study, an adhesive strength of 17 N/12 mm was achieved by degreasing and etching pretreatment, followed by a sealing process of 10 min duration. This adhesive strength was greater than that achievable using Cr (chromium) surface treatment. Using various surface analysis techniques, the shape and composition of the surface before and after being subjected to the surface treatment were compared and analyzed. The results of this study are expected to contribute to the development of an eco-friendly lead tab.

• Transactions of the Korean hydrogen and new energy society
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• v.32 no.6
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• pp.612-617
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• 2021

In the case of a metal sulfide electrode, it is used as an anode or cathode active material in a lithium battery. The reason is that the voltage exists between 0.8 and 2.0 V via lithium electrode and the discharge and charge capacity is high. In order to manufacture nickel sulfide for electrode, which are widely used, nano-nickel powder was sulfided using ammonium polysulfide, and single-phase NiS electrodes were manufactured through heat treatment. The prepared NiS electrode had a high initial capacity of 500 mAh/g or more, and was stabilized after 20 cycles to maintain a capacity of 400 mAh/g or more until 100 cycles.

• Bulletin of the Korean Chemical Society
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• v.31 no.9
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• pp.2698-2700
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• 2010

• Applied Chemistry for Engineering
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• v.22 no.4
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• pp.395-399
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• 2011

Material of the gasket for lithium ion battery requires the chemical resistance, the electrical insulting property, the compression set, the anti-contamination level and the low temperature resistance. We compounded ethylene propylene diene monomer (EPDM), which showed widely different solubility parameter index, with adjusting the amount of metal oxide as an activator. We did long-term test and compression set against an electrolyte with consideration for operating conditions in lithium-ion battery. In these tests, we checked the physical, chemical characteristics and the effect to lithium ion battery with different kinds of activators. In case of rubber with ZnO as an activator, through 1000 h depositing test in propylene carbonate which is one of representative solvents, we could get the satisfying characteristics and result. However, $Zn^{2+}$ had eluted in the ion elution test. So, ZnO should be limited in EPDM compound for the gasket material in lithium-ion battery.

• Journal of the Korean Electrochemical Society
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• v.8 no.4
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• pp.168-171
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• 2005

The electrochemical properties of $LiFePO_4$ as a cathode for Li-ion batteries were improved by incorporating conductive carbon into the $LiFePO_4$. X-ray diffraction analysis and SEM observations revealed that the carbon-coated $LiFePO_4$ consisted of fine single crystalline particles, which were smaller than the bare $LiFePO_4$. The electrochemical performance of the carbon-coated $LiFePO_4$ was tested under various conditions. The carbon-coated $LiFePO_4$ showed much better performance in terms of the discharge capacity and cycling stability than the bare $LiFePO_4$. The improved electrochemical performances were found to be attributed to the reduced particle size and enhanced electrical conductivity of the $LiFePO_4$ by the carbon.

• Journal of Energy Engineering
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• v.20 no.2
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• pp.109-122
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• 2011

The production capacity of EV models should be sufficient to achieve the goal of one million EVs by 2015. Large-Format lithium-ion battery are expected to find a prominent role as ideal electrochemical storage systems in traction power train for sustainable vehicles such as all-electric vehicles. This review focuses first on the present status of production lithium-ion battery technology and cooperative relations of between battery and EV makers, then on its near future development.