• 한국산업융합학회 논문집
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• 제25권5호
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• pp.715-724
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• 2022

In many electric vehicles, large-capacity pouch-type lithium-ion battery packs are mainly used to increase the mileage on a single charge. The lithium ion battery should be operated within the temperature range of 25℃ to 40℃ because the battery performance can be rapidly deteriorated due to an increase in internal temperature. Battery thermal management system (BTMS) can give the suitable temperature conditions to battery by water cooling method. In this research, the heat transfer characteristics (the battery temperature distributions and the water flow characteristics) were analyzed by CFD method to investigate the thermal performance of the cooling plate with 4-pass water flow structure. Moreover, the effect of the presence of fins between the battery cell was identified. The fins made smooth temperature distributions between the battery cells due to the heat spreading and lower the average battery cells temperature.

• 멤브레인
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• 제27권1호
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• pp.92-103
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• 2017

본 연구에서는 리튬이온전지용 친수화된 세퍼레이터의 전기화학적 성능에 대한 연구를 진행하였다. 리튬이온전지용 분리막으로 사용되는 폴리올레핀 소재는 소수성이고, 카보네이트 계열의 유기용매를 사용하는 전해액은 친수성을 가진다. 따라서 리튬이온전지는 수계전해액을 사용하기 때문에 폴리올레핀계 분리막에 다양한 친수성 고분자를 도입하여 친수화 처리하였다. 코팅된 세퍼레이터의 변화를 평가하기 위해, 표면 관찰, 코팅시간에 따른 친수화도, 다공성, 젖음성에 대한 특성평가를 수행하였다. 최종적으로 리튬이온이 코팅된 세퍼레이터의 저항과., 이온전도도를 측정하여 리튬이온전지 성능평가를 진행하였다. PMVE로 코팅한 세퍼레이터의 친수화 정도가 우수하며, 세퍼레이터의 기공이 잘 유지되어 우수한 이온전도도를 나타냄으로써 이차전지 배터리에 적용을 위한 잠재성을 가짐을 확인하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.339-340
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• 2012

• 한국가스학회지
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• 제14권3호
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• pp.14-20
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• 2010

본 논문은 리튬이온전지의 불꽃방전에 의한 폭발위험성에 관한 연구로서 휴대용기기의 전원으로 사용되는 리튬이온전지(일반용, 노트북용)를 시료로 선정하고, 폭발성 시험가스인 메탄, 프로판, 에틸렌, 수소를 대상으로 IEC형 불꽃점화 시험장치를 이용하여 불꽃점화실험을 실시하여 불꽃방전에 의한 폭발위험성을 규명하였다. 또한, 사고 시 단락전류에 의한 자체점화 가능성을 확인하고자 열화상카메라를 이용하여 온도변화를 측정하였다. 실험결과 리튜이온전지는 폭발성가스가 존재하는 폭발위험장소에서 사용할 때는 안전에 각별히 주의하여 사용 설계되어야 한다.

• 한국기계가공학회지
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• 제20권12호
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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.

• Journal of Power Electronics
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• 제14권5호
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• pp.1038-1046
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• 2014

Lithium-ion batteries are widely used in hybrid and pure electric vehicles. State-of-charge (SOC) estimation is a fundamental issue in vehicle power train control and battery management systems. This study proposes a novel model-based SOC estimation method that applies closed-loop state observer theory and a comprehensive battery model. The state-space model of lithium-ion battery is developed based on a three-order resistor-capacitor equivalent circuit model. The least square algorithm is used to identify model parameters. A multi-state closed-loop state observer is designed to predict the open-circuit voltage (OCV) of a battery based on the battery state-space model. Battery SOC can then be estimated based on the corresponding relationship between battery OCV and SOC. Finally, practical driving tests that use two types of typical driving cycle are performed to verify the proposed SOC estimation method. Test results prove that the proposed estimation method is reasonably accurate and exhibits accuracy in estimating SOC within 2% under different driving cycles.

• 한국항공우주학회지
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• 제37권11호
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• pp.1157-1163
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• 2009

본 논문은 과학기술위성3호 리튬이온 배터리의 배터리 운용 시스템에 대해 소개한다. 위성에 전력을 공급하기위한 리튬이온 배터리의 요구조건과 리튬 이온 배터리의 운용 시스템의 전반적인 디자인 방법들을 설명하였다. 더 나아가 이러한 설계 내용들을 검증하기 위하여 검증 모델을 제작하여 기능 테스트들을 수행하였고 이러한 결과 들을 통해서 BMS와 사용된 리튬이온 cell의 성능을 확인하였다.

• 세라미스트
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• 제21권4호
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• pp.406-415
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• 2018

Lithium ion batteries have been widely adopted as energy storage and the LIB global market has grown fastest. However, LIB players have struggled against maximizing energy density since commercial monolithic electrodes are limited by electrolyte depletion caused by long and tortuous Li-ion diffusion pathways. Recently, new strategies designing the structure of battery electrodes strive for creating fast Li-ion path and alleviating electrolyte depletion problem in monolithic electrodes. In this paper, given the fundamental and experimental approaches, we compare the monolithic to structured electrodes and demonstrate the ways to fabricate high energy, fast chargeable Lithium ion battery.

• International Journal of Internet, Broadcasting and Communication
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• 제15권3호
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• pp.118-121
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• 2023

Recently, green energy support policies have been announced around the world in accordance with environmental regulations, and asthe market grows rapidly, demand for batteries is also increasing. Therefore, various methodologies for battery diagnosis and recycling methods are being discussed, but current accurate life prediction of batteries has limitations due to the nonlinear form according to the internal structure or chemical change of the battery. In this paper, CS2 lithium-ion battery measurement data measured at the A. James Clark School of Engineering, University of Marylan was used to predict battery performance with high accuracy using a convolutional neural network (CNN) model among deep learning-based models. As a result, the battery performance was predicted with high accuracy. A data structure with a matrix of total data 3,931 ☓ 19 was designed as test data for the CS2 battery and checking the result values, the MAE was 0.8451, the RMSE was 1.3448, and the accuracy was 0.984, confirming excellent performance.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2009년도 춘계학술대회 논문집
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• pp.72-75
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• 2009

In this paper, lithium-ion-polymer battery based standalone photovoltaic energy storage is presented. conventional system was difficult to choose hi-directional DC-DC converter because of unbalanced voltage of batteries. The other side, lithium-ion-polymer battery hardly contains unbalanced voltage between each batteries. And Lithium Polymer Battery is clean battery because is doesn't contain heavy metals such as Nickel, Cadmium. We analyzed validity of algorithms according to load pattern for the system through the simulation and experimental results.