• 제목/요약/키워드: $^{55}Mn$

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리튬 2차 전지용 Li[Co0.1Ni0.15Li0.2Mn0.55]O2 양극물질의 안정성 고찰 (Stability of Li[Co0.1Ni0.15Li0.2Mn0.55]O2 Cathode Material for Lithium Secondary Battery)

  • 박용준
    • 한국전기전자재료학회논문지
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    • 제20권5호
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    • pp.443-449
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    • 2007
  • The structural and thermal stability of $Li[Co_{0.1}Ni_{0.15}Li_{0.2}Mn_{0.55}]O_2$ electrode during cycling process was studied. The sample was prepared by simple combustion method. Although there were irreversible changes on the initial cycle, O3 stacking for $Li[Co_{0.1}Ni_{0.15}Li_{0.2}Mn_{0.55}]O_2$ structure was retained during the first and subsequent cycling process. Impedance of the test cell was decreased after the first charge-discharge process, which would be of benefit to intercalation and deintercalation of lithium ion on subsequent cycling. As expected, cycling test for 75 times increased impedance of the cell a little, instead, thermal stability of $Li[Co_{0.1}Ni_{0.15}Li_{0.2}Mn_{0.55}]O_2$ was improved. Moreover, based on DSC analysis, the initial exothermic peak was shifted to high temperature range and the amount of heat was also decreased after cycling test, which displayed that thermal stability was not deteriorated during cycling.

중성자조사 금속 과망간산염의 반조효과 (Recoil Effects of Neutron-Irradiated Metal Permanganates)

  • Lee, Byung-Hun;Kim, Jung-Gwan
    • Nuclear Engineering and Technology
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    • 제20권2호
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    • pp.105-111
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    • 1988
  • 과망간산염들, 즉 과망간산 칼륨, 과망간산 암모늄, 과망간산 바륨에서 망간의 중성자 포획으로 야기되는 화학적 효과를 고찰하였다. $^{55}$Mn(n, r) $^{56}$ Mn 반응에서 생성된 방사성 망간 화학종, 즉 양이온 56/Mn, $^{56}$ MnO$_2$ 그리고 $^{56}$ MnO$_4$$^{-}$의 분포에 미치는 용제의 pH효과를 여러 가지 흡착제들과 이온교환체, 즉 제올이프 A-3, 카올리나이트, 알루미나, 이산화망간 그리고 도엑스 -50을 이용하여 고찰하였다. 카올리나이트와 알루미나에서 방사성 MnO$_4$$^{-}$의 분포가 대표적인 pH값인 4, 7 그리고 9 각각에서 다른흡착제와 이온교환체보다 높게 나타나며 동일한 흡착제일경우에는 pH 4 는 및 pH 9에서가 pH 7에서보다 높게 나타난다. $^{55}$Mn(n, r) $^{56}$ Mn 반응에 의하여 과망간산염에서 생성된 반조망간원자들의 열-어니어링 거동 또한 고찰하였다. 열-어니어링에서 $^{56}$ MnO$_4$$^{-}$의 잔류율은 10$0^{\circ}C$ 및 13$0^{\circ}C$ 처리에서 온도가 높아질수록 증가함을 보였다. 망간염의 반조효과는 hot zone model로 설명하였다.

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$MnO_2$가 첨가된 $(Pb_{0.45}Ca_{0.55})(Fe_{0.5}Nb_{0.5})O_3$ 세라믹스의 마이크로파 유전특성 (Microwave Dielectric Properties of $MnO_2$ Added $(Pb_{0.45}Ca_{0.55})(Fe_{0.5}Nb_{0.5})O_3$ Ceramics)

  • 이상민;이두희;윤현상;박창엽
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1993년도 정기총회 및 추계학술대회 논문집 학회본부
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    • pp.237-239
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    • 1993
  • $MnO_2$ added $(Pb_{0.45}Ca_{0.55})(Fe_{0.5}Nb_{0.5})O_3$ was calcined at $850^{\circ}C$ for two hours and sintered at $1100^{\circ}C$ for two hours. The microstructure was examined using XRD and SEM. The dielectric constant, the quality factor, and the temperature stability was measured using Hakki and Coleman method. Dielectric constant was improved to 94 from 0.5wt% $MnO_2$ added sample with $Q{\cdot}f=4260GHz$ and acceptable ${\tau}_f$ (< $20ppm/^{\circ}C$).

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Electrochemical Properties of 0.3Li2MnO3·0.7LiMn0.55Ni0.30Co0.15O2 Electrode Containing VGCF for Lithium Ion Battery

  • Kim, Jeong-Min;Jeong, Minchan;Jin, Bong-Soo;Kim, Hyun-Soo
    • Journal of Electrochemical Science and Technology
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    • 제5권1호
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    • pp.32-36
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    • 2014
  • The $0.3Li_2MnO_3{\cdot}0.7LiMn_{0.55}Ni_{0.30}Co_{0.15}O_2$ cathode material was prepared via a co-precipitation method. The vapor grown carbon fiber (VGCF) was used as a conductive material and its effects on electrochemical properties of the $0.3Li_2MnO_3{\cdot}0.7LiMn_{0.55}Ni_{0.30}Co_{0.15}O_2$ cathode material were investigated. From the XRD pattern, the typical complex layered structure was confirmed and a solid solution between $Li_2MnO_3$ and $LiMO_2$ (M = Ni, Co and Mn) was formed without any secondary phases. The VGCF was properly distributed between cathode materials and conductive sources by a FE-SEM. In voltage profiles, the electrode with VGCF showed higher discharge capacity than the pristine electrode. At a 5C rate, 146 mAh/g was obtained compared with 232 mAh/g at initial discharge in the electrode with VGCF. Furthermore, the impedance of the electrode with VGCF did not changed much around $9-10{\Omega}$ while the pristine electrode increased from 21.5${\Omega}$ to $46.3{\Omega}$ after the $30^{th}$ charge/discharge cycling.

망간용액조방법에 도입되는 국산 황산망간중의 불순물 분석 (Impurity Analysis of Domestic $MnSO_4{\cdot}H_2O$ Introduced to Manganese Bath Method)

  • 황선태;이경주;최길용;이광우;우진춘;이기범
    • Journal of Radiation Protection and Research
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    • 제12권1호
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    • pp.48-53
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    • 1987
  • 중성자 선원의 강도를 측정하기 위하여 흔히 황산망간용액조 방법이 사용되고 있다. 본 연구에서는 $^{55}Mn(n,{\gamma})^{56}Mn$ 반응에 도입되는 국산 $MnSO_4{\cdot}H_2O$(동양화학제품)중에 불순들 성분을 규명하기 위하여 Ar-ICP 플라즈마방출 분광계측에 의한 분석화학 방법이 사용되었다. 분석결과로부터 주로 Co, Zn과 미량의 Cd, Li 등이 관련 불순물로서 중성자를 흡수하는 것으로 판명되었으며 전체 불순물에 의한 중성자 흡수 비율은 $^{55}Mn$에 의하여 포획되는 중성자 수의 약 1.37%로 산정되었다.

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