• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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• pp.1083-1088
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• 2004

Zinc air batteries obtain their energy density advantage over the other batteries by utilizing ambient oxygen as the cathode materials, and reusing cathode as recycled form. And specific capacity of zinc powder is as high as 820mAh/g. Our research team succeeded in producing 2.4 Ah class zinc air battery for cellular phone application. In this paper we had studied performance of cathode according to various factors and demonstrated the performance of 2.4 Ah class zinc air battery for cellular phone application.

• 한국전기전자재료학회논문지
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• 제17권9호
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• pp.936-941
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• 2004

In recent years, the rapid growth of portable electronic devices requires the high-energy density characteristics of batteries. Zinc air batteries have specific capacity as high as 820mAh/g. However, Zinc air batteries used for hearing aid applications only so far, because the atmosphere could affect it, and it has weakness in the rate capability. However, recent developments of electrode manufacturing technologies made us to overcome that weakness. And the efforts of applying zinc air batteries to portable electronic devices, especially in cellular phone application have been increased. In this paper, the effects of conducting material and polymer binder in cathode on the electrochemical characteristics were investigated. Our research team succeeded in producing 2.4Ah class zinc air battery for cellular phone application. Its volumetric energy density was 920 wh/l, and gravimetric energy density was 308 wh/kg. The volumetric energy density of our zinc air battery is two times higher than one of lithium secondary battery, and three times higher than that of alkaline manganese battery.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집A
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• pp.778-782
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• 2000

Deep drawing and ironing are the major process used today in manufacturing of battery case used in cellular phone and IMT-2000 from aluminum. The same technology is utilized in manufacturing of steel or aluminum rectangular cans for components of medical instrument, portable PC, walkman and so on. Most of these processes require multi-stage ironing following the deep drawing and redrawing processes. The practical aspects of this technology are well known and gained through extensive experiment and production know-how. However, the fundamental aspects of theses processes are relatively less known. Thus, it is expected that process simulations using FEM techniques would provide additional detailed information that could be utilized to improve the process condition. This paper illustrates the application of process modeling to deep drawing and redrawing operations with the cellular phone and IMT-2000. A commercially avaliable finite element code LS-DYNA3D was used to simulate deep drawing and redrawing operations.

• 전기화학회지
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• 제10권1호
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• pp.31-35
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• 2007

이 리뷰를 통하여, 휴대폰용 리튬이차전지의 최근 기술동향을 설명하였다. 휴대폰용 이차전지로는 니카드, 니켈-금속수소, 리튬이온 혹은 리튬이온폴리머의 세 가지 형태의 전지가 있으며, 리튬 이차전지가 에너지밀도 측면에서 가장 성능이 우수하다. 즉, 동일한 용량을 갖는 이차전지 가운데 가장 작고 가벼운 것은 리튬이차전지이다. 이러한 리튬이차전지의 시장은 매년 약 15%의 높은 성장을 기록하고 있다. 연구개발은 $LiFePO_4$를 포함하는 새로운 양극, $Li_4Ti_5O_{10}$, Si, 주석 등의 새로운 음극소재, 새로운 전해질과 안정성 확보에 관한 것을 중심으로 진행되고 있다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2000년도 추계학술대회 논문집
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• pp.97-100
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• 2000

Today deep drawing and ironing are the major process in manufacturing of battery case used in cellular phone from aluminum. The same technology is utilized in manufacturing of steel or aluminum cans for components of medical instrument, portable PC, walkman and so on. Most of these processes require multi-stage ironing following the deep drawing and redrawing processes. The practical aspects of this technology are well known and gained through extensive experiment and production know-how. However, the fundamental aspects of theses processes are relatively less known. Thus, it is expected that process simulations using FEM techniques would provide additional detailed information that could be utilized to improve the process condition. This paper illustrates the application of process modeling to deep drawing and redrawing operations for High Precision Rectangular Battery Case. A commercially avaliable finite element code LS-DYNA3D was used to simulate deep drawing and redrawing operations.

• 한국안전학회지
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• 제19권3호
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• pp.32-39
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• 2004

This papers describes on the experimental consideration for the intrinsically-safe explosion-proof capability of rechargeable battery's body about main item rechargeable battery and cellular phone battery which is selling in domestic that IEC(International Electrotechnical Commission) recommend the measurement of ignition limit by short circuit of rechargeable battery and temperature increase test to use a explosion grade Group IIC type of explosion-proof type apparatus test an object of hydrogen gas. Because of that there are many different results for existence or nonexistence for ignition by different company and different types. It is concluded that the maximum of self temperature increasing by spark circuit of rechargeable battery is $180^{\circ}C$ in case of Nickel-Hydrogen and $110^{\circ}C$ in case of Nickel-Cadmium. The reaction of cellular battery for external temperature have following processes. It is confirmed that the temperature of reaction is rise slantly as the ambient temperature rising, then exterior shape of one is swell up and change when the temperature of ambient reach to about $130\~140^{\circ}C$, and when reach to about $160^{\circ}C$ the battery is blown up. Therefore, it is considered that have to be in considering selection of rechargeable battery using in itself due to different ignition limits of various rechargeable battery when the portable electric containing rechargeable battery are designed, produced and used, the characteristics and the proper safety factors of devices.

• 한국화재소방학회논문지
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• 제25권6호
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• pp.21-26
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• 2011

본 논문에서는 에너지원에 따른 이동전화기(SCH_W830) 배터리의 소손 패턴을 제시함으로써 소비자분쟁 해결의 자료로 활용하고자 한다. 실험이 진행될 때의 주위 온도는 $22{\pm}2^{\circ}C$, 습도는 40~60 %를 유지함으로써 신뢰성을 확보하였다. 실험에 사용된 이동전화기의 배터리 전압은 양극(+)과 음극 (1)(-) 사이의 전압은 4.19 V이며, 양극(+)과 음극 (2)(-) 사이의 전압은 4.18 V로 측정되었다. 일반화염 인가에 의한 이동 전화기의 난연성 시험은 한국산업규격(KS)을 적용하였으며, 일반화염이 30 sec 동안 외함에 인가되어도 내장된 배터리의 소손은 없는 것으로 확인되었다. 생리 식염수(NaCl, 0.9%)에 이동전화기를 180 sec 침수시킨 결과 배터리 단자 사이에 누설전류에 의한 발열로 탄화 및 용융이 발생한 흔적을 확인할 수 있었다. 전자레인지(MWO)를 이용하여 70 sec 동안 이동전화기를 가열하면 금속홀더, 충전용 커넥터, 안테나 등이 내장된 부분에서 용융 및 변색이 확인되며, 그 밖의 부분은 특이사항이 없는 것을 알 수 있다. 즉, 인가된 에너지원의 종류에 따라 이동전화기 외형의 탄화, 내장된 금속 및 유전체, 배터리 단자대의 손상 및 변형 등이 다르게 발생하지만 전압은 비교적 일정한 특성을 보이는 것으로 보아 연소의 확산 패턴, 금속의 용융 및 변형 부분의 특성을 종합적으로 고려하여 해석하면 소손 원인 판정이 가능하다.

• 한국의류학회지
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• 제29권7호
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• pp.918-925
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• 2005

The following are the results from the infrared body temperature image test to verify the changes in facial temperature according to call duration with a cellular phone. As for the body temperatures, it appears to be the mean value at the upper central point of phone's battery among 7 different points that are measured, and to be the highest at srernocleido-mastoid and scapular trapezius muscle triangle zone$(34.25^{\circ}C\; and\;34.05^{\circ}C\;each)$. The changes of body temperature according to the time duration shows that the body temperature rises according to the length of phone use because of the heat emitted from the battery. As for the temperature changes according to blocking materials, the one without processing appears to be higher in the mean temperature compared to the others that are processed, NSS(Nano Silver Silk) and NSG(Nano Silver Silk Gold) appear to be the lowest in the temperature to show the best blocking property. As for the temperature changes according to measuring points, it appears to be the highest at P4, P5 with all materials, and one with NSG to be the lowest at Pl, P2, P3, and one with NSS to be the lowest at P3, P4, P5, P6, which is due to the thermal conduction of Au and Ag. And the mean temperature at each point appears to be different according to the materials. Therefore, the study conducted with human participants requires a proper particle size of it which would not penetrate cellular tissues and a proper binder and binding treatment for it, to prevent the physical fatigues and the potential diseases. However, it is highly required for back-up researches to verify various aspects in applying nano silver to textile products.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.1074-1076
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• 2000

This Paper reports on an experimental and theoretical work about self exited Half-Bridge inverter for contact less battery chargers. The steady state characteristics of inverter are analysis and the experimental result for 500kHz, universal AC source input have been obtained. These inverter is suitable for the portable appliances with battery chargers such as cellular phone.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제49권4호
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• pp.265-271
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• 2000

A non-contact battery charger for cellular phone is designed using half-bridge series resonant converter. This converter utilizes series resonance to reduce the undesirable effect of large leakage inductance of the detachable transformer and ZVS operation can reduce switching loss and switching noise. In this paper, analysis and design procedure of half-bridge series resonant converter with detachable transformer is presented. The input voltage is 85VAC∼270VAC, and the output voltage and current is 4.1V and 800mA, respectively. Furthermore, a method of calculating the secondary current of the transformer to control the battery charging current in the constant current charging mode is proposed. The performance of the charger is verified through experiments.