• Title/Summary/Keyword: Charge-Transfer

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The AC impedance of $LiM_{y}Mn_{2-y}O_{4}$cathode material by charge and discharge temperature (충방전 온도에 따른 $LiM_{y}Mn_{2-y}O_{4}$정극 활물질의 임피던스 특성 분석)

  • 정인성;구할본
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.11a
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    • pp.351-354
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    • 2000

  • AC impedance of LiM $n_2$ $O_4$ and LiM $g_{0.1}$M $n_{1.9}$ $O_4$ samples have been studied at various temperature with charge-discharge test. AC impedance of LiM $n_2$ $O_4$ measured at -2$0^{\circ}C$, room temperature and 5$0^{\circ}C$ revealed that initial impedance before charge-discharge test was gradually decreased and become small by becoming law temperature. It indicates that the Li ion diffusion and the transfer resistance of the cathode are related to the temperature of cycling. Impedance at high temperature was suddenly increased because Mn dissolution and decomposition of electrolyte had been increased during cycling, compared to impedance at low temperature. Therefore, charge-discharge capacity was suddenly decreased at high but was slowly at low. In LiM $g_{0.1}$M $n_{1.9}$ $O_4$, impedance and capacity were stability at room temperature than there at 5$0^{\circ}C$, too. Initial impedance at 5$0^{\circ}C$ before charge-discharge test was small and impedance was suddenly increased during cycling than that at room temperature.ure.ure.

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A Direct Cell-to-Cell Charge Balancing Circuit for the EV Battery Module (전기자동차 배터리 모듈용 직접 셀 전하 균등화 회로)

  • Pham, Van-Long;Nguyen, Kim-Hung;Basit, Khan Abdul;Choi, Woojin
    • Proceedings of the KIPE Conference
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    • 2015.07a
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    • pp.401-402
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    • 2015

  • In this paper a direct cell-to-cell charge balancing circuit which can transfer the charge from any cell to any cell in the battery string is introduced. In the proposed topology the energy in the high voltage cell is transferred to the low voltage cell through the simple operation of a dc-dc converter to get fast equalization. Furthermore, the charge equalization can be performed regardless of the battery module operation whether it is being charged, discharged or relaxed. The monitoring circuit composed of a DSP and a battery monitoring IC is designed to monitor the cell voltage and protect the battery. In order to demonstrate the advantages of the proposed topology, a prototype circuit was designed and applied to 12 Lithium-Ion battery module. It has been verified with the experiments that the charge equalization time of the proposed method was shortest compared with those of other methods.

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