• Title/Summary/Keyword: $Li/SOCl_2$ cell

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Studies on Improved Carbon Cathode Performance in High Rate $Li/SOCl_2$ Cell (고율 방전용 $Li/SOCl_2$ 전지의 카본 양극 개선에 관한 연구)

  • 최정자;조성백;박희숙
    • Journal of the Korean Ceramic Society
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    • v.34 no.3
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    • pp.225-232
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    • 1997
  • The performance characteristics of high rate discharge LiSOCl2 cells are highly affected by carbon cathode. During the cell discharge, SOCl2 reduction takes place at the porous carbon cathode, resulting in the precipitation of reaction products, mainly LiCl, within the pores of the substrate. This leads to eventual passivation of the cathode surface and resulting cell failure. To improve the cathode performance, we ex-amined discharge reactions of cathodes (half-cell, 50 mA/$\textrm{cm}^2$ constant current) with various surface density and thickness. The carbon cathode with the optimum capacity for our application is surface density 0.04 g/$\textrm{cm}^2$ and thickness 1.4mm carbon. The carbon cathode with surface density 0.04g/$\textrm{cm}^2$ and thickness 1.4 mm exhibits decreased polarization, increased discharge duration time and capacity (Ah/$\textrm{cm}^2$) as compared with that with surface density 0.04g/$\textrm{cm}^2$ and thickness 0.8mm. The porosities analyses on the two carbon cathodes show that total pore volume of the carbon cathode with thickness 1.4 mm is larger than that with thickness 0.8mm. The increased volume of mesopores (0.05$\mu$m~0.5$\mu$m) and macropores(>0.5$\mu$m) is ob-served with the carbon cathode with thickness 1.4mm as compared with that with thickness 0.8mm, which can be related with the observed capacity increase. We observed LiCl crystals, cubic crystallites and fused, plate-like aggregates, and some elemental S as discharge products by EDS and XRD.

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Studies on electrocatalytic effects of LiAlCl4/SOCl2 cell by tetradentate Schiff base metal(II) complexes (네자리 Schiff base 금속(II) 착물들에 의한 LiAlCl4/SOCl2 전지의 전기촉매 효과에 대한 연구)

  • Sim, Woo-Jong;Jeong, Byeong-Goo;Na, Kee-su;Chjo, Ki-Hyung;Choi, Yong-Kook
    • Applied Chemistry for Engineering
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    • v.7 no.3
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    • pp.416-423
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    • 1996
  • Electrochemical reduction of thionyl chloride in 1.5 M $LiAlCl_4/SOCl_2$ electrolyte solution containing tetradentate Schiff base Co(II), Ni(II), Cu(II), and Mn(II) complexes has been investigated at the glassy carbon electrode. The catalyst molecules of transition metal(II) complexes were adsorbed on the electrode surface and reduced thionyl chloride resulting in a generation of oxidized catalyst molecules. There was an optimum concentration for each catalyst compound. The current density of $SOCl_2$ reduction was enhanced up to 150% at the catalyst contained electrolyte solution. The reduction currents of thionyl chloride were increased and the reduction potentials were shifted to the negative potential as scan rates became faster. The reduction of thionyl chloride was proceeded to diffusion controlled reaction.

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Electrocatalytic Effects for the Reduction of Thionyl Chloride in $Li/SOCl_2$ Cell Containing Schiff Base Metal(II) Complexes

  • Kim, Woo-Seong;Chung, Kwang-Il;Kim, Shin-Kook;Jeon, Seung-Won;Kim, Yeon-Hee;Sung, Yung-Eun;Choi, Yong-Kook
    • Bulletin of the Korean Chemical Society
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    • v.21 no.6
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    • pp.571-576
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    • 2000
  • Electrocatalytic effects for the reduction of thionyl chloride in $LiAICI_4/SOCl_2$ electrolyte solution containing Schiff base M(II) (M; Co and Fe) complexes are evaluated by determining kinetic parameters with cyclic voltammetry and chronoamperometry at a glassy carbon electrode. The charge transfer process during the reduction of thionyl chloride is affected by the concentration of the catalyst. The catalytic effects are demonstrated from both a shift of the reduction potential for the thionyl chloride toward a more positive direction and an increase in peak currents. Catalytic effects are larger in thionyl chloride solutions containing the binuclear [M(II) $_2$ (TSBP)] complex rather than mononuclear [M(II)(BSDT)] complexes. Significant improvements in the cell performance have been noted in terms of both thermodynamics and activation energy for the thionyl chloride reduction. The activation energy calculated from the Arrhenius plots is 4.5-5.9 kcal/mole at bare glassy carbon electrodes. The activation energy calculated for the catalyst containing solution is 3.3-4.9 kcalmole, depending on whether the temperature is lowered or rasied.