• Journal of IKEEE
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• v.28 no.1
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• pp.14-19
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• 2024

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 charge·discharge capacity was approximately 18.9~19.3[%] lower than that of a new cell. Because internal resistance and charge·discharge 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 charge·discharge capacity performance of 70[%] or more.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.275-278
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• 1997

We investigated effectness of sort and volume of conductive agent to charge/discharge capacity of LiMn$_2$O$_4$. LiMn$_2$O$_4$is prepared by reacting stoichiometric mixture of LiOH . $H_2O$ and MnO$_2$(mole ratio 1 : 2) and heating at 80$0^{\circ}C$ for 24h, 36h, 48h, 60h and 72h. All LiMn$_2$O$_4$cathode active materials show spinel structure. Cathode active materials calcined at 80$0^{\circ}C$ for 36h, charge/discharge characteristics and cycle stability have remarkable advantages. Used that super-s-black and 20wt% as conductive agent in LiMn$_2$O$_4$, it is excellent than property of cathode used Acetylene black or mixture of Super-s-black and acetylene black at charge/discharge capacity and cycle stability. Also, specific efficiency of cathode is excellent as over 98% and that of first cycle is excellent as 92%.

• Journal of the Korean Vacuum Society
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• v.9 no.1
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• pp.36-41
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• 2000

$SnO-2$ thin films for thin film secondary battery anode were deposited n glass substrate with stain-less steel collector and charge/discharge experiments were conducted to investigate feasibility of $SnO-2$ thin film as a new anode material. The as-deposited films were pure $SnO-2$ phase which is not related to deposition condition. The grain size on the surface of as-deposited films increased with increase of oxygen partial pressure. However, the grain size did not show any change above oxygen partial pressure of 80:20. The surface roughness of the as-deposited films increased after decreasing because of resputtering effect of oxygen negative ion in plasma. All films showed typical $SnO-2$ anode characteristics which has a side effect at the first cycle, which is not related to the deposition condition. The charge/discharge experiments of 200cycles indicated that capacity of $SnO-2$ films depended on oxygen contents and surface roughness. The cycle characteristics was determined by initial charge/discharge reaction. The $SnO-2$ film with low initial capacity showed more stable cycle characteristics than film with high initial capacity.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.9
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• pp.656-661
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• 2013

In this study, the moisture content, charge discharge current, electrostatic capacity and dielectric loss tangent are measured for the specimen of bisphenol type epoxy resin which is mixed with squared amorphous silica filler and dipped in hot water of $50^{\circ}C$ for 169 days. The results of this study are listed below. The longer of deposition day, the charge and discharge current was increased. It is considered that the reason is because there was water attack through the squared silica surface. The longer of deposition day, the absorption rate of all specimens was increased. It found that the absorption rate reached saturated state after 100 days. The higher frequency and the longer of deposition day, the $tan{\delta}$ was decreased. Also, It found that the $tan{\delta}$ and electrostatic capacity of the specimen which is mixed with squared filler are greater.

• Journal of the Semiconductor & Display Technology
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• v.15 no.2
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• pp.55-60
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• 2016

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.

• Carbon letters
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• v.5 no.3
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• pp.118-126
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• 2004

MCMB (Mesocarbon microbeads) is a kind of anode material for lithium-ion secondary battery. MCMB charge/discharge cycle stability is one of the important criterion at lithium-ion battery operation. In this study, the cycling stability of a lithium-ion secondary battery has been examined. MCMB was made by the direct solvent extraction method. After the MCMB was carbonized and graphitized, the measurement of charge/discharge capacity and efficiency were carried out. In the result, discharge capacity of MCMB in the initial cycle was above 290.0 mAh/g. After the second cycle, efficiency of charge/discharge MCMB was about 98%. These results were similar to the commercial MCMB product.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.371-374
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• 2000

The electrochemical properties of LiM $n_2$ $O_4$as a cathode and an anode for the lithium secondary battery were evaluated. When LiM $n_2$ $O_4$ material was used as the cathode with the current collector of aluminum, the 1st specific capacity and the 1st Ah efficiency in LiM $n_2$ $O_4$/lithium cell were 123 mAh/g and 91.7%, respectively The anodic properties of LiM $n_2$ $O_4$ material was also evaluated in the LiM $n_2$ $O_4$/1ithium cell with the current collector of copper. It showed that the LiM $n_2$ $O_4$ was useful as the anode for the lithium secondary battery. During the 1st discharge, a potential plateau was observed at the potential of 0.3 $V_{Li}$ Li+/. The 1st specific charge capacity and the 1st specific discharge capacity were 790 mAh/s and 362 mAh/g, respectively. Therefore, the 1st Ah efficiency was 46%. The discharge capacity was gradually faded with the charge-discharge cycling to about 50th cycles. Thereafter, the discharge capacity was stabilized to about 110 mAh/g.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.11
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• pp.1224-1229
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• 2004

The purpose of this study is to research and develop tin oxide-flyash composite for lithium Ion polymer battery. Tin oxide is one of the promising material as a electrode active material for lithium Ion polymer battery (LIPB). Tin-based oxides have theoretical volumetric and gravimetric capacities that are four and two times that of carbon, respectively. We investigated cyclic voltammetry, AC impedance and charge/discharge cycling of SnO$_2$-flyash/SPE/Li cells. The first discharge capacity of SnO$_2$-flyash composite anode was 639 mAh/g. The discharge capacity of SnO$_2$-flyash composite anode was 563 and 472 mAh/g at 6th and 15th cycle, respectively. The SnO$_2$-flyash composite anode with PVDF-PMMA-PC-EC-LiClO$_4$ electrolyte showed good capacity with cycling.

• Journal of the Korean Society for Nondestructive Testing
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• v.33 no.2
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• pp.198-204
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• 2013

Acoustic emission(AE) signal was detected during charge and discharge of lithium ion battery to investigate relationships among cumulative count, discharge capacity, and microdamages. AE signal was received during accelerated charge/discharge cycle test of a coin-type commercial battery. A number of AE signals were successfully detected during charge and discharge, respectively. With increasing number of cycle, discharge capacity was decreased and AE cumulative count was observed to increase. Microstructural observation of the decomposed battery after cycle test revealed mechanical damages such as interface delamination and microcracking of the electrodes. These damages were attributed to sources of the detected AE signals. Based on a linear correlation between discharge capacity and cumulative count, feasibility of AE technique for evaluation of battery degradation was suggested.

• 한국전기화학회:학술대회논문집
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• 1998.12a
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• pp.7-27
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• 1998

In order to design capacity of lithium ion battery, some calculations were carried out based on the characteristics of materials by the given battery shape and dimension. The principle of design was built by the interpretation of the correlation of material, electrochemical and battery factors. Parameters of materials are fundamental physical properties of constituent such as cathode. separator, anode, current collectors and electrolyte. Electrochemical factor includes potential pattern as a function of specific capacity, specific discharge capacity(or initial irreversible specific capacity or Ah efficiency) as a function of specific charge capacity and material balancing. Parameters of battery are dimension, construction hardware and performance. Battery capacity was simulated for a lithium cobalt dioxide as cathode and a hard carbon as anode to achieve 1100 mAh for the charge limit voltage of 4.2V, the weight ratio(+/-) of 2.4 and ICR18650. A fabricated test cell (ICR18650) which have weight ratio(+/-) of 2.4 discharged to 1093 mAh for the charge limit voltage of 4.2V. The sequential discharge capacity show good correspondence with designed capacity.