• Journal of the Semiconductor & Display Technology
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• v.13 no.1
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• pp.101-108
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• 2014

The battery pack in this research consists of dozens of a small battery for energy storage. And this battery pack charges and discharges repeatedly at high capacity (25 ~ 50 V, 25 ~ 100 A). The high temperature which can be generated in this process has a bad effect to the lifetime and efficiency of batteries. Moreover these factors are related with maintenance cost. Therefore, we need to assess the thermal performance of the battery pack in advance using the experimental or numerical analysis. In this research, we analyzed voltage and surface temperature of one cell battery to calculate heat transfer using the numerical analysis. And the temperature of the battery surfaces and inside of the pack was also analyzed. As a result, we found out the appropriate pack structure which stacked five modules.

• Safety and Health at Work
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• v.15 no.1
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• pp.114-117
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• 2024

A lithium-ion battery is a rechargeable battery that uses the reversible reduction of lithium ions to store energy and is the predominant battery type in many industrial and consumer electronics. The lithium-ion batteries are essential to ensure they operate safely. We conducted an exposure assessment five days after a fire in a battery-testing facility. We assessed some of the potentially hazardous materials after a lithium-ion battery fire.We sampled total suspended particles, hydrogen fluoride, and lithium with real-time monitoring of particulate matter (PM) 1, 2.5, and 10 micrometers (㎛). The area sampling results indicated that primary potential hazardous materials such as dust, hydrogen fluoride, and lithium were below the recommended limits suggested by the Korean Ministry of Labor and the American Conference of Governmental Industrial Hygienists Threshold Limit Values. Based on our assessment, workers were allowed to return to work.

• Transactions of the Korean hydrogen and new energy society
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• v.26 no.1
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• pp.54-63
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• 2015

The secondary battery using sodium is investigating as one of power storage system and power in electric vehicles. The secondary battery using sodium as a sodium battery and sodium ion battery had merits such as a abundant resources, high energy density and safety. Sodium battery (sodium molten salt battery) is operated at lower temperature ($100^{\circ}C$) compared to NAS and ZEBRA battery ($300{\sim}350^{\circ}C$). Sodium ion battery is investigating as one of the post lithium ion battery. In this paper, it is explained for the principle and recent research trends in sodium molten salt and sodium ion battery.

• Journal of Electrical Engineering and Technology
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• v.13 no.5
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• pp.1927-1934
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• 2018

In this paper, we studied the state of charge (SOC) estimation algorithm of a high-capacity lithium secondary battery for electric vehicles (EVs) considering temperature characteristics. Nonlinear characteristics of high-capacity lithium secondary batteries are represented by differential equations in the mathematical form and expressed by the state space equation through battery modeling to extract the characteristic parameters of the lithium secondary battery. Charging and discharging equipment were used to perform characteristic tests for the extraction of parameters of lithium secondary batteries at various temperatures. An extended Kalman filter (EKF) algorithm, a state observer, was used to estimate the state of the battery. The battery capacity and internal resistance of the high-capacity lithium secondary battery were investigated through battery modeling. The proposed modeling was applied to the battery pack for EVs to estimate the state of the battery. We confirmed the feasibility of the proposed study by comparing the estimated SOC values and the SOC values from the experiment. The proposed method using the EKF is expected to be highly applicable in estimating the state of the high-capacity rechargeable lithium battery pack for electric vehicles.

• Transactions of the Korean hydrogen and new energy society
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• v.31 no.5
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• pp.489-497
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• 2020

The Li-ion battery is considered to be one of the potential power sources for electric vehicles. In fact, the efficiency, reliability, and cycle life of Li-ion batteries are highly influenced by their thermal conditions. Therefore, a novel thermal management system is highly required to simultaneously achieve high performance and long life of the battery pack. Basically, thermal modeling is a key issue for the novel thermal management of Li-ion battery systems. In this paper, as a basic study for battery thermal modeling, temperature distributions inside the simple Li-ion battery pack (comprises of nine 18650 Li-ion batteries) under a 1C discharging condition were investigated using measurement and computational fluid dynamics (CFD) simulation approaches. The heat flux boundary conditions of battery cells for the CFD thermal analysis of battery pack were provided by the measurement of single battery cell temperature. The temperature distribution inside the battery pack were compared at six monitoring locations. Results show that the accurate estimation of heat flux at the surface of single cylindrical battery is paramount to the prediction of temperature distributions inside the Li-ion battery under various discharging conditions (C-rates). It is considered that the research approach for the estimation of temperature distribution used in this study can be used as a basic tool to understand the thermal behavior of Li-ion battery pack for the construction of effective battery thermal management systems.

• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.5
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• pp.486-493
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• 2015

In this paper, a battery model for electric vehicle virtual platform was developed. A battery model consisted of a battery cell model and battery thermal management system. A battery cell model was developed based on Randles equivalent circuit model. Circuit parameters in the form of 3D map data was obtained by charge-discharge experiment of Li-Polymer battery in various temperature condition. The developed battery cell model was experimentally verified by comparing voltages. Thermal management system model was also developed using heat generator, heat transfer and convection model, and cooling fan. For verification of the developed battery model in vehicle level, the integrated battery model was applied in to EV(electric vehicle) virtual platform, and virtual driving simulation using UDDS velocity profile was conducted. The accuracy of the developed battery model has been verified by comparing the simulation results from EV platform with the experimental data.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.12
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• pp.54-64
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• 2021

Electric vehicles use lithium-ion battery packs as the power supply, where the batteries are connected in series or parallel. The temperature control of each battery is essential to ensure a consistent overall temperature. This study focused on reducing ohmic heating caused by batteries to realize a uniform battery temperature. The battery spacing was optimized to improve air cooling, and the tilt angle between the batteries was varied to optimize the internal structure of the batterypack. Simulations were performed to evaluate the effects of these parameters, and the results showed that the optimal scheme effectively achieved a uniform battery temperature under a constant power discharge. These findings can contribute to future research on cooling methods for battery packs.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1048-1050
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• 1995

Lead-acid battery is used widely as a power source at a automobile, industrial machines, folk lifts, U.P.S. etc. Lead-acid battery is cheaper than arty other secondary battery, but this battery has many disadvantages such as heavy, low energy density, environment problem etc. In this article, we introduce cyclic voltammetry methods to investigate corrosion behaviour of positive grids of Pb-Ca alleys.

• Fire Science and Engineering
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• v.33 no.2
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• pp.98-106
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• 2019

As lithium batteries have been used for car navigation systems and as the second battery for black boxes, lithium battery-related car fires have often occurred. In the case a lithium battery is the fire origin, a fire investigation technique has not been established to determine if a battery ignites or whether the lithium battery is damaged by fire. This study introduced car fire cases related to lithium batteries, analyzed the causes of a fire of a lithium battery, and proposed fire investigation techniques to objectively determine if a lithium battery ignites or whether a lithium battery is damaged by fire after external ignition.

• Journal of Satellite, Information and Communications
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• v.12 no.4
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• pp.95-99
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• 2017

The lifetime of a battery that supplies all the power required by a satellite in the eclipse is directly related to the lifetime of the satellite. Because the lifetime of the battery is influenced by the charging method of the battery, the power control unit that controls the charging of the battery should be designed in consideration of battery life. The battery charging is performed by controlling the charge current in the power control unit generated from the solar cell in the daytime. In order to prevent overcharge of the battery and for considering frequency of eclipse in each season, parameters related battery charging should be designed differently according to the season and to prevent over-current charging and over-voltage charging during charging, charge current is controlled by monitoring battery charge / discharge status, charge current amount, battery voltage, battery capacity, battery temperature and battery cell voltage. In satellite, tapering method is used to control charge current by reflecting each condition. In this paper, design battery charging algorithm of satellite power control unit using tapering charging method. convert the designed algorithm into a code that can be uploaded to satellites and verify the operation through testing in the established satellite environment.