• Proceedings of the KIPE Conference
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• 2011.11a
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• pp.22-23
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• 2011

본 논문은 Battery의 열화 특성을 반영한 순차적 Step Charge를 통한, Mobile 기기용 Li-Ion Smart Battery의 Life Cycle 개선기술을 제안 하고자 한다. 현재 기술수준의 Li-Ion 2차전지 수명은 표준충방전 300~500cycle 내외이나. 초기용량을 희생하지 않고도 Smart Battery 내부의 ASOC(Absolute State of Charge)와 연동하여 Battery 수명열화 곡선을 추종하는 최적화된 가변 충전전압을 순차적 Step Charge로 제공하여 Li-Ion 2차 전지의 수명열화를 개선하고, 열화 특성의 검토 및 개선효과 확인을 논문의 목적으로 한다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.7
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• pp.576-579
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• 2009

This paper suggests a autonomous linear Li-ion battery charger which can safely distribute power between an external power source(AC adapter, auto adapter, or USB source), battery, and the system load. Depending on an external power source's capability, the charger selects proper charging-mode automatically. The charger IC designed and fabricated on Dongbu HITEC's $0.35{\mu}m$ BCD process with layers of one poly and three metals.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.04b
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• pp.27-28
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• 2009

This paper suggests a autonomous linear Li-ion battery charger which can safely distribute power between an external power source(AC adapter, auto adapter, or USB source), battery, and the system load. Depending on an external power source's capability, the charger selects proper charging-mode automatically. The charger IC designed and fabricated on Dongbu HITEC's $0.35{\mu}m$ BCD process with layers of one poly and three metals.

• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.207-210
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• 1990

The purpose of this study is to research and develop polymer secondary battery. This paper describes the first discharge characteristics of PAn/Li-Al secondary battery. PAn was prepared in $HBF_4$ aqueous solution by galvanostatic electropolymerization and then used as cathode active material. PAn/Li-Al secondary battery was prepared in 2025 coin type. Characteristics of this battery are summarized as follows. ${\bullet}$ Open curcuit voltage and discharge end voltage was 3.5V and 2.9V, respectively. ${\bullet}$ The ratio of electricities in discharge to theoretical electricities in all undoping of PAn cathode was 56% at constant current discharge of 1mA. ${\bullet}$ The capacity density, energy density and maximum power density per weight of PAn electroactive material were 56.1Ah/kg, 168.4Wh/kg and 16.9kW/kg, respectively.

• Journal of Electrochemical Science and Technology
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• v.10 no.2
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• pp.250-255
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• 2019

Poly(ethylene oxide) (PEO)-based solid polymer electrolytes (SPEs) show promise for improving the lithium ion battery safety. However, due to oxidation of the PEO group and corrosion of the Al current collector, PEO-based SPEs have not previously been effective for use in $LiCoO_2$ (LCO) cathode materials at room temperature. In this paper, a semi-interpenetrating polymer network (semi-IPN) PEO-based SPE was applied to examine the performance of a LCO/SPE/Li metal cell at different voltage ranges. The results indicate that the SPE can be applied to LCO-based lithium polymer batteries with high electrochemical performance. By using a carbon-coated aluminum current collector, the Al corrosion was mostly suppressed during cycling, resulting in improvement of the cell cycle stability.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.6
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• pp.49-57
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• 2013

In this study, we fabricated a parallelly connected Li-ion battery/supercapacitor hybrid cell to combine the advantageous characteristics of Li-ion battery and supercapacitor, high energy density and high power density, respectively, and investigated its discharging characteristics over a wide temperature range from -40 to $25^{\circ}C$. At the initial state of discharging of the hybrid cell, the power was mostly provided by the supercapacitor and then the portion of the Li-ion battery was gradually increased. By installing a switching system into the hybrid cell, which controls the discharging sequence of Li-ion battery and supercapacitor, the maximum power was improved by 40% compared with non switching system. In addition at low temperatures, the power and discharging time of the hybrid cell were significantly enhanced compared to a battery-alone system. The hybrid cell is expected to be applied in electric vehicles and small domestic appliances that require high power at initial discharging state.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.597-598
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• 2005

Recently, the performance of portable electric equipment can often improved by a Li-ion battery assisted by a supercapacitor. A supercapacitor can provide high power density as well as a low resistance in the hybrid system. In this study, we have prepared, as the pluse power souce, a commercially supplied Li-ion battery with a capacity of 700mAh and AC resistivity of $60m\Omega$ at 1kHz and nonaqeous asymmetric hybrid capacitor composed of an activated carbon cathode and MCMB anode, and have examined the electrochemical characteristics of hybrid capacitor and the pulse performances of parallel connected battery/hybrid capacitor source. The nonaqueous asymmetric hybrid capacitor, the stacks of 10 pairs of the cathode, the porous separator and the anode electrode were housed in Al-laminated film cell. The hybrid capacitor, which was charged and discharged at a constant current at $0.25mA/cm^2$ between 3 and 4.3V, has exhibited the capacitance of 100F. And the equivalent series resistance was $32m\Omega$ at 1kHz. By combining a Li-ion battery and a hybrid capacitor, the pulse performance of battery can be improved 23% in run time under a pulse discharge of 7C-rate.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.497-497
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• 2007

활성탄소를 양쪽 전극에 사용하는 전기이중층 커패시터는 고출력 특성과 반영구적인 cycle 수명인 장점을 가지고 있는 반면, 단위 중랑 또는 부피 당 용량이 작아 메모리 백업용 보조전원으로서의 활용에 그치고 있다. 이를 보완하기 위하여 최근에는 앙쪽의 전극에 충방전 메카니즘을 달리하는 비대칭 전극 설계기술을 기반으로 하는 하이브리드 커패시터가 개발되었고, 에너지밀도로서는 유기계 전해액에서 약 15-20 Wh/kg를 가지는 것으로 보고되고 있다. 본 연구메서는 양극의 활성탄소에 비용량이 상대적으로 큰 LiCo02 분말을 혼합한 하이브리드 전극의 제조 및 전기화학적 특성을 조사하였다. 이때 $LiCoO_2$ 분말의 혼합 종량비의 영향에 의한 전극 부피 당 용량(mAh/cc)의 변화와 $LiCoO_2$ 분말의 입자 크기에 의한 하이브리드 전극의 출력 특성을 조사하였다. $LiCoO_2$ 분말은 불밀을 이용하여 입자크기를 조절하였고, 각각의 입자크기를 가지는 LiCoO2 분말을 활성탄소와 함께 혼합하여 혼합 활물질 : Carbon black : PTFE의 중량비가 90 : 5 : 5가 되도록 sheet 전극을 제조하였다. 제조한 전극을 양극에, Li foil을 음극에, 전해액을 LiPF6 in EC DMC를 사용하여 코인셀을 제조하고 전기화학적 특성은 MACCOR 충방전기를, AC 저항은 AC impedance를 각각 사용하여 평가하였다. 활성탄소에 $LiCoO_2$ 분말의 첨가 중량비가 증가할수록 전극 부피 당 용량은 증가하였으나, 원료 상태의 $LiCoO_2$ 분말의 첨가에서는 코인셀의 전극 저항은 첨가 중량에 따라 단순 증가하였다. 그러나 미세 $LiCoO_2$ 분말을 첨가할 경우, 20%의 첨가에서 전극 저항은 활성탄소 만을 사용한 전극과 동등한 전극저항을 나타내고 충방전 cycle 특성도 개선되는 것을 확인하였다.

• Resources Recycling
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• v.25 no.3
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• pp.82-87
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• 2016

The discharged products of Li-$O_2$ and Na-$O_2$ batteries using ether-based electrolyte as next-generation battery system were analyzed. The morphology of the discharged products showed millet-like shape in the both battery systems by FESEM. However, the discharged product, $Li_2O_2$ showed amorphous-like form in the Li-$O_2$ cell while crystalline $NaO_2$ is formed in the Na-$O_2$ cell when confirmed by X-ray diffraction. In this work, we comprehended a principle operating mechanism of Li-$O_2$ and Na-$O_2$ battery.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.2
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• pp.150-157
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• 2014

Li-Ion battery is used in the most satellites now due to advantages such as weight, thermal dissipation and self discharge compared to the previous generations of electrochemical batteries. The performance analysis model of the Li-Ion battery is needed to aid the design of new satellite electrical power subsystem. This paper develops the performance analysis model of the Li-Ion battery to apply to the electrical power subsystem design and energy balance analysis on geostationary orbit. The analysis model receives the satellite bus power, solar array power and battery temperature and gives the battery voltage, charge and discharge currents, taper index, state of charge and power dissipation. The results from the performance analysis are compared and analyzed with the flight data to verify the model. The compared results show satisfactory without significant difference with the flight data.