• 대한임베디드공학회논문지
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• 제17권2호
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• pp.85-92
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• 2022

Currently, various researches on electric vehicle battery systems have been conducted from the viewpoint of safety and performance for SoC, SoH, etc. However, it is difficult to build a precise electrical model of a battery system based on the chemical reaction and SoC prediction. Experimental measurements and predictions of the battery SoC were usually performed using dynamometers. In this paper, we construct a simulation model of an electric vehicle system using Matlab Simulink, and confirm the response characteristics based on the vehicle test driving profiles. In addition, we show that it is possible to derive the correlation between the SoC, voltage, and current of the battery according to the driving time of the electric vehicle in conjunction with the BMS model.

• Bulletin of the Korean Chemical Society
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• 제31권11호
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• pp.3221-3224
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• 2010

This study investigates the requirements of lithium-air cathodes, which directly influence discharge capacity. The cathodes of Li-air cell are made by using five different carbon materials, such as Ketjen black EC600JD, Super P, Ketjen black EC300JD, Denka black, and Ensaco 250G. The Ketjen black EC600JD provides discharge capacity of 2600 mAh/g per carbon weight, while that of Ensaco 250G shows only 579 mAh/g. To figure out the differences of discharge capacity from carbon materials, their surface area and pore volume are analyzed. These are found out to be the critical factors in determining discharge capacity. Furthermore, carbon loading on Ni foam and amounts of electrolyte are significant factors that affect discharge capacity. In order to investigate catalyst effect, electrolytic manganese dioxide (EMD) is incorporated and delivered 4307 mAh/g per carbon weight. This infers that EMD facilitates to break $O_2$ interactions and leads to enhance discharge capacity.

• Transactions on Electrical and Electronic Materials
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• 제16권3호
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• pp.135-138
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• 2015

A manganese dioxide (MnO₂) layer and zinc (Zn) layer are used as the cathode and the anode to develop filmtype manganese battery, in which a stack of a MnO₂ layer, gel electrolyte, and Zn layer are sandwiched between two plastic layers. This paper describes the chemical equation of swelling control upon the film-type manganese battery. We examined the reduction of hydrogen formation, by using calcium hydroxide Ca(OH)₂ as an additive in the electrolyte of film-type manganese battery. The phenomena or an effect of reduced hydrogen gas was proven by cyclic voltammogram, X-ray photoelectron spectra (XPS), and volume of hydrogen formation. The amount of H₂ gas generation in the presence of Ca²⁺ ion was reduced from 4.81 to 4.15 cc/g-zinc (14%), and the corrosion of zinc electrode in the electrolyte was strongly inhibited as time passed.

• Bulletin of the Korean Chemical Society
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• 제30권7호
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• pp.1607-1610
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• 2009

The carbon-coated Si/Cu powder has been prepared by mechanical ball milling and hydrocarbon gas decomposition methods. The phase of Si/Cu powder was analyzed using X-ray diffraction (XRD), dispersive Raman spectroscopy, electron probe microanalysis (EPMA) and transmission electron microscope (TEM). The carbon-coated Si/Cu powders were used as anode active material for lithium-ion batteries. Their electrochemical properties were investigated by charge/discharge test using commercial LiCo$O_2$ cathode and lithium foil electrode, respectively. The surface phase of Si/Cu powders consisted of carbon phase like the carbon nanotubes (CNTs) with a spacing layer of 0.35 nm. The carbon-coated Si/Cu/graphite composite anode exhibited a higher capacity than commercial graphite anode. However, the cyclic efficiency and the capacity retention of the composite anode were lower compared with graphite anode as cycling proceeds. This effect may be attributed to some mass limitations in LiCo$O_2$ cathode materials during the cycling.

• Korean Chemical Engineering Research
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• 제46권6호
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• pp.1119-1123
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• 2008

마이크로파를 이용하여 주석산화물을 제조한 후에 리튬이온전지의 음극활물질로 사용하였다. 시료들은 마이크로파를 이용하여 가열한 후에 산소분위기에서 300, 500, $700^{\circ}C$로 3시간 열처리하였다. 마이크로파로 제조한 주석산화물의 전기화학적인 특성과 가역용량을 고찰하였다. $500^{\circ}C$로 가열한 주석산화물이 $300^{\circ}C$와 $700^{\circ}C$로 가열한 시료보다 높은 가역용량을 나타내었다. 마이크로파 가열과 전기로 가열을 비교한 결과 마이크로파 가열이 높은 가역용량을 나타내었다. 마이크로파 가열과 $500^{\circ}C$ 가열한 주석산화물의 경우에 초기 방전용량이 1,500 mAh/g으로 나타났다.

• Bulletin of the Korean Chemical Society
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• 제17권9호
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• pp.861-863
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• 1996

• Bulletin of the Korean Chemical Society
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• 제21권2호
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• pp.169-174
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• 2000

• Bulletin of the Korean Chemical Society
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• 제34권6호
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• pp.1651-1655
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• 2013

Anion exchange membranes for a vanadium redox flow battery (VRB) were prepared by pore-filling on a PE substrate with the copolymerization of vinylbenzyl chloride (VBC) and glycidyl methacrylate (GMA). The ion exchange capacity, water uptake and weight gain ratio were increased with a similar tendency up to 65% of GMA content, indicating that the monomer improved the pore-filling degree and membrane properties. The vanadium ion permeability and open-circuit voltage were also investigated. The permeability of the VG65 membrane was only $1.23{\times}10^{-7}\;cm^2\;min^{-1}$ compared to $17.9{\times}10^{-7}\;cm^2\;min^{-1}$ for Nafion 117 and $1.8{\times}10^{-7}\;cm^2\;min^{-1}$ for AMV. Consequently, a VRB single cell using the prepared membrane showed higher energy efficiency (over 80%) of up to 100 cycles compared to the commercial membranes, Nafion 117 (ca. 58%) and AMV (ca. 70%).

• 한국응용과학기술학회지
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• 제20권2호
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• pp.130-140
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• 2003

In order to improve the lithium ion battery's performance, the carbon nanofibers were introduced to the anode electrode fabricated with natural graphite particles. The influence of structural adjustment of the particles by the introduction method of carbon nanofibers and the content of carbon nanofibers on the electrical property and charge/discharge characteristics of the electrode were investigated. The electrode fabricated with the mixture of 10 wt% of carbon nanofibers grown separately and 90 wt% of graphite particles showed an excellent discharge capacity of 400 mAh/g and the improved cycle performance. The improved performance could be explained by that the carbon nanofibers shortened and uniformly distributed on the surface of graphite particles by ball milling increased the stability for the intercalation/deintercalation of lithium ion and increased the electrical conductivity due to the closed packing between graphite particles.

• International Journal of Internet, Broadcasting and Communication
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• 제16권3호
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• pp.228-235
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• 2024

Battery use is increasing worldwide to achieve carbon neutrality and improve energy efficiency, but batteries are a finite resource and their application is determined by capacity and specifications. Battery performance deteriorates as the number of uses increases. A certain level of battery performance degradation has become an issue in the field of reuse and recycling, and various studies are being conducted on reuse to solve power shortages. Waste batteries from electric vehicles are suitable for building ESS based on reusable batteries, and for stable use, technical skills are needed to accurately predict battery life and determine status information. Predicting battery life and determining status information are difficult due to non-linearity due to internal structure or chemical changes. In this paper, we manufactured a modular internal resistance measuring device and compared the measured values with Hioki equipment to minimize the error rate through a correction method. As a result of testing Hioki equipment and modular measuring instruments to ensure efficiency and safety based on reusable batteries, an accuracy of over 95% was confirmed.