Zr과 Mn 기초의 AB_2형 금속수소화물의 원소치환에 의한 전기화학적 특성 향상

權益鉉,宋明燁 대한금속재료학회 2002 대한금속·재료학회지 Vol.40 No.7

A series of multicomponent Zr_0.8,Ti_0.2Mn_0.4V_0.6Ni_(1-x)Fe_x (x=0.00, 0.08, 0.15, 0.22 and 0.30) alloys are prepared and their crystal structure and P-C-T curves are examined. The electrochemical properties of these alloys such as activation conditions, discharge capacity, cycling performance are also investigated. Zr_0.8,Ti_0.2Mn_0.4V_0.6Ni_(1-x)Fe_x, (x=0.00, 0.08, 0.15, 0.22 and 0.30) have the C14 Laves phase hexagonal structure. The electrode was activated by the hotcharging treatment. The best activation conditions were the current density 120 ㎃/g and the hot-charging time 12h at 80℃ in the case of the alloy with x=0.00. The discharge capacity increased rapidly until the fourth cycle and then decreased. The discharge capacity increased again from the 13th cycle, arriving at 234 mAh/g at the 50th cycle. The discharge capacity just after activation decreases with the increase in the amount of the substituted Fe but the cycling performance is improved. The discharge capacity after activation of the alloy with x=0.00 is 157 ㎃h/g at the current density 60 ㎃/g. Zr_0.8,Ti_0.2Mn_0.4V_0.6Ni_0.85Fe_0.15 shows a medium quantity of discharge capacities but a good cycling performance. Another series of multicomponent Zr_0.8,Ti_0.2Mn_0.4V_0.6Ni_0.85Fe_0.15 (M=Fe, Co, Cu, Mo and Al) alloys are prepared. They also have the C14 Laves phase hexagonal structure. The alloys with M=Co and Fe have relatively larger hydrogen storage capacities. The discharge capacities just after activation are relatively large in the case of the alloys with M=Al and Cu. They are 212 and 170 ㎃h/g, respectively, at the current density 60 ㎃/g. Of the alloys investigated, the Zr_0.8,Ti_0.2Mn_0.4V_0.6Ni_0.85Fe_0.15 alloy is the best one showing a relatively large discharge capacity and a good cycling performance. This alloy contains more Ni as compared with the other alloys, and the small particles of this alloys are the clusters of very fine particles. The ICP analysis of the electrolyte for these electrodes after 50 charge-discharge cycles shows that the concentrations of V and Zr are relatively high.

다채널 대용량 충방전기 모듈 개발에 대한 연구

이준하 한국반도체디스플레이기술학회 2016 반도체디스플레이기술학회지 Vol.15 No.2

This study was developed through the secondary battery module charging/discharger possible utilization in the production process equipment circuit. The developed module is ensuring construction of efficient and productive charging and discharger through this research a limit on the yield and the price of existing single -channel charge and discharger circuit as a 5V 70A grade secondary battery Formation charge and discharger for up to 1 board 4 channels. In order to improve the sensing accuracy, through a robust differential amplifier circuit described using 16bit Analog-Digital Converter and noise was secured 16bit resolution sensing. The configuration also made demands for property Rise / Fall Time. Data Acquisition, discharge efficiency and also to fit the sink circuit temperature level for mass production.

"주택용 BESS에 적용하기 위한 재활용 셀의 성능에 관한 연구"

김필중,양성수 한국전기전자학회 2024 전기전자학회논문지 Vol.28 No.1

"주택용 BESS에 적용하기 위한 재활용 셀 성능을 파악하기 위해 지난 5년 동안 사용한 셀을 선택하였다. 시험에 사용된 셀의 기본사양은 공칭 전압이 3.7[V], 공칭 용량이 2,200[mAh], 충전 전압이 4.05[V], 연속방전전류가 1[C](2,200[mA]), 연속충전전류가0.5[C](1,100[mA]) 이다. 새 셀의 경우 내부저항은 21.3±1[mΩ]인데, 재활용 셀의 경우 평균 내부저항이 25.38[mΩ]로 나타나 약19.1[%] 상승하였다. 충ㆍ방전 용량은 새 셀에 비해 약 18.9~19.3[%] 정도 낮게 나타났다. 내부저항과 충ㆍ방전 용량이 셀의 노화에 상호 밀접하게 연관되어 있으므로 BESS에 적용할 셀은 초기 내부저항보다 1.5배 이하이고 70[%] 이상의 충ㆍ방전 용량 성능을갖는 제품을 사용할 필요가 있다." "To determine the performance of recycled cells for application to residential BESS, cells used over the past 5 years were selected. The basic specifications of the cell used in the test are nominal voltage of 3.7[V], nominal capacity of 2,200[mAh], charging voltage of 4.05[V], continuous discharge current of 1[C](2,200[mA]), continuous charging current of 0.5[C](1,100[mA]). For new cells, the internal resistance was 21.3±1[mΩ], but for recycled cells, the average internal resistance was 25.38[mΩ], an increase of about 19.1[%]. The chargeㆍdischarge capacity was approximately 18.9~19.3[%] lower than that of a new cell. Because internal resistance and chargeㆍdischarge capacity are closely related to cell aging, cells to be applied to BESS need to use products with an initial internal resistance of 1.5 times or less and a chargeㆍdischarge capacity performance of 70[%] or more."

정극 활물질 Li(Cr_0.4Mn_0.6)O₂의 충ㆍ방전 특성

위성동,정인성,구할본,Wee, Sung-Dong,Jeong, In-Seong,Gu, Hal-Bon 한국전기전자재료학회 2004 전기전자재료학회논문지 Vol.17 No.10

An impedance properties of the positive active material Li(Cr$_{0.4}$Mn$_{0.6}$)O$_2$ are measured by the changeable trend to the time. The charge-discharge capacities of 297 mAh(g)$^{-1}$ 175 mAh(g)$^{-1}$ are obtained by the made cell with the active material that the Cr was added to LiMnO$_2$ to prevent structural degradation of an electrode active material with impedance of 75 Ω to get at an initial hour. Resultantly, these variations which the impedances enhanced continually, were not watched the impeditive variations as the results of the delay time that the positive thin films and the references have been soaked all together in the solution of electrolyte of 1M LiPF$_{6}$ EC/DEC(l/2). Accordingly, it means an amount increased of the discharged capacities in the view of the results that the impeditive values were decreased are known already through a authorized paper.per.

Modeling of Battery for EV using EMTP/ATPDraw

Kim, Jun-Hyeok,Lee, Soon-Jeong,Kim, Eung-Sang,Kim, Seul-Ki,Kim, Chul-Hwan,Prikler, Laszlo The Korean Institute of Electrical Engineers 2014 Journal of Electrical Engineering & Technology Vol.9 No.1

As environmentally friendly energy takes center stage, interests for Electric Vehicles/Plug in Hybrid Electric Vehicles (EVs/PHEVs) are getting increase. With this trend, there is no doubt EVs will take large portion to penetrations of total cars. Therefore, accurate EV modeling is required. Battery is one of the main components with the power system view of aspect. Hence, in this paper, reviews and discussions of some types of batteries for EV are contained by considering energy density and weight of the batteries. In addition, simulations of Li-Ion battery are accomplished with various variables such as temperature, capacity fading and charge/discharge current. It is confirmed that temperature is the main factor of capacity fading. Validation of the modeled battery is also conducted by comparing it with commercialized battery.

Modeling of Battery for EV using EMTP/ATPDraw

Jun-Hyeok Kim,Soon-Jeong Lee,Eung-Sang Kim,Seul-Ki Kim,Chul-Hwan Kim,Laszlo Prikler 대한전기학회 2014 Journal of Electrical Engineering & Technology Vol.9 No.1

As environmentally friendly energy takes center stage, interests for Electric Vehicles/Plug in Hybrid Electric Vehicles (EVs/PHEVs) are getting increase. With this trend, there is no doubt EVs will take large portion to penetrations of total cars. Therefore, accurate EV modeling is required. Battery is one of the main components with the power system view of aspect. Hence, in this paper, reviews and discussions of some types of batteries for EV are contained by considering energy density and weight of the batteries. In addition, simulations of Li-Ion battery are accomplished with various variables such as temperature, capacity fading and charge/discharge current. It is confirmed that temperature is the main factor of capacity fading. Validation of the modeled battery is also conducted by comparing it with commercialized battery.

$LiCoO_2/MPCF$전지에서 정$\cdot$부극 중량비의 영향

김상필,조정수,김희제,박정후,윤문수,Kim Sang-Pil,Cho Jeong-Soo,Kim Hee-Je,Park Jeong-Hu,Yun Mun-Soo 한국전기화학회 1999 한국전기화학회지 Vol.2 No.2

Li-ion 2차전지는 정극재료로 리튬전이금속산화물을, 부극재료로 탄소를 사용한다. 고용량 및 장수명을 지닌 Li-ion 2차 전지를 제작하기 위하여, 충전중에 탄소표면에 리튬 석출이 없이 전극 활물질의 이용율은 가능한 높아야 한다. 정극 및 부극 재료의 balance 및 적절한 충전 방식이 Li-ion 2차전지의 설계에 있어서 중요한 요소이다. 본 연구에서는 $LiCoO_2/MPCF$전지의 성능에 미치는 정$\cdot$부극 중량비의 효과를 고찰하였다. 먼저 각 반전지의 충방전 특성을 평가하였다. 그리고 흑연화 MPCF를 부극으로, $LiCoO_2$를 정극으로 사용하여 원통형 Li-ion 2차전지를 제작하였다. 기준전극으로 리튬금속을 사용하여 $LiCoO_2/MPCF$전지에서 각 반전지의 전위를 측정하였다. 또한 중량비에 따른 $LiCoO_2/MPCF$ 전지의 충방전 수명 성능을 평가하였다. 시험 결과, $LiCoO_2$ 정극의 이용율은 중량비에 의존하지 않지만, MPCF부극 이용율은 중량비에 크게 의존하였다. 또한, $LiCoO_2/MPCF$전지의 최적 중량비는 $2.0\~2.2$인 것으로 판단되었다. Li-ion cells employ lithium transtion metal oxide as the cathode material and carbon as anode material. To manufacture Li-ion cell with higher capacity and better cycle life, the utilization of electrode materials should be as high as possible without lithium deposition onto the carbon surface during charging. A careful design of cell balance between cathode and anode materials as well as a proper charge method is a key factor to design Li-ion cell with long cycle life. In this study, we investigated the effect of cathode/anode weight ratio on the performance of $LiCoO_2/MPCF$ cell. First we evaluated the charge-discharge behaviours of half-cells. And cylindrical Li-ion cells were fabricated using graphitized MPCF anode and $LiCoO_2$ cathode. The voltage profiles for each half-cell in $LiCoO_2/MPCF$ cell were measured by using lithium metal as a reference electrode. Also, we evaluated the cyclic performance of $LiCoO_2/MPCF$ cells according to weight ratio. From the result of experiment $LiCoO_2$ cathode utilization was independent of weight ratio, but MPCF anode utilization was dependant on weight ratio. Also, the optimal weight ratio of $LiCoO_2/MPCF$ cell was found to be $2.0\~2.2$.

리튬 이온 전지의 용매 분해 반응에 대한 연구

정광일,최병두,김신국,김우성,최용국,Chung Kwang-il,Choi Byeong-doo,Kim Shin-Kook,Kim Woo-Seong,Choi Yong-Kook 한국전기화학회 1998 한국전기화학회지 Vol.1 No.1

1M LiPF_6/EC:DME(1:1) 전해질 용액에서 시간-전위차법, 순환 전압-전류법, 시간-전류법 , 그리고 임피던스법을 이용하여 리튬 이온 전지의 충방전 용량을 조사하였고 초기 충전과정에서 용매 분해로 형성된 필름의 영향을 알아보았다. 충 방전 결과에 따르면, 1 M $LiPF_6/EC:DME$를 이용한 반쪽전지의 초기 비가역 용량은 상당히 크게 나타났다 이러한 비가역 용량은 대부분 용매 분해에 의한 것으로 해석되었으며, 용매 분해로 인하여 MPCF전극 표면에 필름이 형성되었다. 초기 충전과정에서 형성된 필름은 방전과정에서 산화되지 않았으며 2번째 충전부터 용매 분해는 더 이상 관찰되지 않았다. 또한 초기 충전과정에서 EC:DME용매속의 Li이 MPCF층 속으로 삽입될 때 용매와 함께 삽입됨을 알 수 있었다. 이러한 삽입이 진행될 때 MPCF표면의 입자들이 박리되고, 박리된 입자들과 용매 분해 생성물들이 서로 섞여 필름을 형성하므로써 필름의 저항은 크게 나타났다. The electrochemical behavior of film and charge-discharge capacity of Li-ion cell in 1 M $LiPF_6/EC:DME$ (1 : 1, by volume ratio) electrolyte solution was studied using chronopotentiometry, cyclic voltammetry, chronoamperometry, and impedance spectroscopy. The first irreversible capacity was higher than the second irrversible capacity because of solvent decomposition. Especially, passivation film that is electron insulating and ionic conducting were formed on the MPCF by solvent decomposition during the first charge. The solvated Li is co-intercalated with solvent into MPCF electrode. Part of the MPCF is expoliated during co-intercalation of solvent-Li. The MPCF ends up nonuniformly covered by a relatively thick layer of exfoliated particles embedded in a matrix of product by solvent decomposition.

A facile pyrolysis method to prepare vanadium oxides for high performance aqueous Zn-ion battery

Zhu Haitao,Liao Shengyun,Su Boya,Ding Xiaohui,Liu Qiang 한국물리학회 2022 Current Applied Physics Vol.34 No.-

Vanadium oxides, as one of the most promising cathode materials for zinc ion batteries, have attracted extensive attention in recent years. Different from the generally used hydrothermal and solvothermal methods to adjust the composition, structure, morphology and electrical properties of vanadium oxides, we firstly adopt a simple pyrolysis method to synthesize a series of vanadium oxides and use them as cathode materials for aqueous Zn-ion battery, whose electrochemical performances is superior to most state-of-the-art vanadium oxides. The asobtained V4O7 under the calcination temperature of 700 ◦C exhibits excellent zinc ion storage performance with maximum specific capacity of 367.2 mAh g 1 at the current density of 1 A g 1, about 84.9% capacity retention after 100 cycles, excellent rate performance, high capacity. In addition, a series of structural and electrochemical characterization are used to reveal the possible mechanism of charge and discharge.

전기적인 특성향상을 위한 리튬이온전지팩 개발

강용구(Young-Gu Gang),권현규(Hyun-Kyu Kweon),서명수(Myung-Su Seo),박창용(Chang-Yong Park) 한국기계가공학회 2009 한국기계가공학회지 Vol.8 No.2

This paper presents a new lithium ion unit-cell and pack battery by using a new formulation ratio of material. The three types of formulation ratio for the unit-cell were used. The life cycle and basic properties of the lithium ion unit-cell(ψ18×65(㎜)) about one of them were acquired by the charge-discharge experiment. The nominal voltage, nominal capacity and cycle life output of the lithium ion unit-cell is respectively 3.7V, 2.4Ah, and above 500cycle. Pack type lithium ion battery has the size of 29.5×73.5×115(㎜) and the weight of 300g. As the results, the weight and bulk of lithium ion battery used to a safety lamp were decreased to 1/4 and 1/7. In addition, the comparison of the new lithium ion battery and lead storge battery for confirming the effectiveness of the new lithium ion battery have been performed.