• Journal of Sensor Science and Technology
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• v.32 no.6
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• pp.462-469
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• 2023

Electric vehicles (EVs) have recently been in the spotlight and have been rapidly developed to reduce the carbon emission with respect to the transport sector. Most EVs currently employ lithium-ion batteries (LIBs) as power sources because they have a higher energy density and a lower self-discharge than other batteries. However, the LIBs cannot respond to high power demands when the state of health (SOH) falls below 80%. Therefore, the SOH of the LIBs must be accurately measured or estimated. To date, many methods have been studied and proposed for measuring or estimating the SOH. In this paper, representative methods among them are reclassified and introduced.

• 한국전기화학회:학술대회논문집
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• 2001.11a
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• pp.211-231
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• 2001

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.4
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• pp.669-676
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• 2024

This study aims to evaluate battery damage and heat transfer mechanisms through fire tests on lithium-ion batteries, and to explore ways to improve the efficiency and safety of battery management systems (BMS). Temperature changes in each sector are measured at points T1, T2, and T3 observing and recording the reactions of surrounding cells for 10 minutes after applying electricity to the ignition electrode. The results show that the batteries in sectors A and B fully ignite, causing severe physical damage, while the batteries in sector C do not ignite and sustain minimal damage. This confirms that the distance between sectors plays a crucial role in reducing ignition and heat propagation. The study suggests that considering the distance between sectors in the design of thermal management systems for lithium-ion batteries can significantly mitigate ignition and heat spread. Future experiments with various battery models and conditions will further propose the ways to enhance the efficiency and safety of BMS.

• Journal of the Korean Electrochemical Society
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• v.27 no.2
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• pp.73-79
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• 2024

As the use of fossil fuels has gradually increased, so has the emission of greenhouse gases such as carbon dioxide, leading to environmental problems. As a result, lithium-ion batteries (LiB) have emerged as the solution to this issue. To manufacture medium to large-sized lithium-ion batteries (LiB), it requires electrodes with high capacity and fast charging capabilities. Silicon (Si) is considered a next-generation anode with high-capacity properties, so, reduced graphene oxide (rGO) was compounded with Si@resorcinol-formaldehyde resin (RF) composite to prevent the volume expansion of Si. It was confirmed that the composite anode prepared exhibited improved capacity and enhanced stability.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.5
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• pp.1067-1074
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• 2024

Various monitoring systems are in operation in large-scale production facilities such as Yeosu Industrial Complex and the power equipment for operating these systems uses protective devices with built-in low-power lithium-ion batteries to cope with poor environments. In this study, a wireless monitoring system was designed and implemented to analyze the usage characteristics of these lithium-ion batteries. By using the system, the temperature and humidity of the protective device including the battery, gas generation due to charging and discharging of the battery within the protective device, and changes in battery characteristics can be monitored wirelessly at all times. Through this system, the stable management and power supply of batteries required for monitoring devices in industrial complexes are provided, thereby contributing to the establishment of an efficient operation and management system for factory production facilities.

• Bulletin of the Korean Chemical Society
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• v.31 no.5
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• pp.1331-1335
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• 2010

A novel spherical carbon composite material, in which nanosized disordered carbons are dispersed in a soft carbon matrix, has been prepared and investigated for use as a potential anode material for lithium ion batteries. Disordered carbons were synthesized by ball milling natural graphite in air. The composite was prepared by mixing the ball-milled graphite with petroleum pitch powder, pelletizing the mixture, and pyrolyzing the pellets at $1200^{\circ}C$ in an argon flow. The ballmilled graphite consists of distorted nanocrystallites and amorphous phases. In the composite particle, nanosized flakes are uniformly distributed in a soft carbon matrix, as revealed by X-ray diffractometer (XRD) and transmission electron microscopy (TEM) experiments. The composite is compatible with a pure propylene carbonate (PC) electrolyte and shows high rate capability and excellent cycling performance. The electrochemical properties are comparable to those of hard carbon.

• Journal of Powder Materials
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• v.10 no.1
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• pp.21-25
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• 2003

The Sn - graphite composites were prepared by chemical encapsulation method for anode materials in Li-ion batteries. EDS and XRD analysis confirmed the presence of Sn in the graphite structure. Cyclic voltammometry (CV) measurement shows extra reduction and oxidation peaks, which might to be related to the formations of $Li_xSn$ alloy compounds. Graphite-tin composite electrodes demonstrated higher Lithium storage capacities than graphite electrodes. Due to the nature of fine Sn particles on graphite surface, the graphite-tin composite electrodes have shown a good cycle properties.

• Bulletin of the Korean Chemical Society
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• v.32 no.9
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• pp.3333-3337
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• 2011

$ZnMn_2O_4$ has been prepared by a mechanochemical process using a mixture of $Mn_2O_3$ and ZnO as starting materials, and investigated as a possible anode material for lithium-ion batteries. The phase evolution and morphologies of the ball-milled and annealed powders are characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy dispersive microanalysis (EDX), respectively. The solid-state reaction for the formation of $ZnMn_2O_4$, under the given experimental conditions, is achieved in a short time (30 min), and the prepared samples exhibit excellent electrochemical performances including an enhanced initial coulombic efficiency, high reversible capacity, and stable capacity retention with cycling.

• Journal of Powder Materials
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• v.24 no.1
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• pp.17-23
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• 2017

In this study, a finite element analysis approach is proposed to predict the fluid-structure interaction behavior of active materials for lithium-ion batteries (LIBs), which are mainly composed of graphite powder. The porous matrix of graphite powder saturated with fluid electrolyte is considered a representative volume element (RVE) model. Three different RVE models are proposed to consider the uncertainty of the powder shape and the porosity. P-wave modulus from RVE solutions are analyzed based on the microstructure and the interaction between the fluid and the graphite powder matrix. From the results, it is found that the large surface area of the active material results in low mechanical properties of LIB, which leads to poor structural durability when subjected to dynamic loads. The results obtained in this study provide useful information for predicting the mechanical safety of a battery pack.

• Journal of Electrochemical Science and Technology
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• v.6 no.2
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• pp.35-49
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• 2015

Advanced polymeric binders with unique functions such as improvements in the electronic conduction network, mechanical adhesion, and mechanical durability during cycling have recently gained an increasing amount of attention as a promising means of creating high-performance silicon (Si) anodes in lithium-ion batteries with high energy density levels. In this review, we describe the key challenges of Si anodes, particularly highlighting the recent progress in the area of polymeric binders for Si anodes in cells.