• 제목/요약/키워드: ionic conductivity

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이온성 액체와 고분자 기반의 이차전지용 고체 전해질의 제조 (Fabrication of ionic liquid and polymer based solid-state electrolyte for secondary battery)

  • 강혜주;정현택
    • 한국응용과학기술학회지
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    • 제37권6호
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    • pp.1591-1596
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    • 2020
  • 고분자를 기반으로 하는 고체전해질은 용이한 가공성, 재료의 유연성뿐만 아니라 배터리, 슈퍼커패시터를 포함하는 이차전지 등 다양한 전기화학 소자에 응용이 가능한 소재로서, 기존 전해질의 낮은 이온전도도 및 전기화학적 안정성을 향상시키기 위하여 다양한 이온성 액체 기반의 고체 전해질에 관한 연구가 활발히 진행 중에 있다. 이온성 액체의 높은 이온전도성, 넓은 전기화학 안정성, 열적 안정성을 활용한 고분자 전해질은 다양한 전자소자에 활용되고 있다. 따라서 본 연구에서는 이온성 액체의 종류와 비율의 최적화를 통하여 고분자 기반의 고체 전해질을 제조하고 전기화학적 성능을 분석하여 이차전지를 포함한 다양한 전자 소자에 응용이 가능한 이온성 액체 기반의 전해질을 개발하고자 하였다. 이온성 액체의 비율을 최적화를 통하여 제조된 고분자 기반 고체 전해질의 이온 전도도는 1.46-2 S/cm로 확인되었다. 이온전도도가 향상된 이온성 액체와 고분자 기반의 고체 전해질은 다양한 이차전지에 활용될 수 있을 것으로 사료된다.

Ionic liquids to the rescue? Overcoming the ionic conductivity limitations of polymer electrolytes

  • Hendcrson W.A.;Shin J.H.;Alessandrini F.;Passcrini S.
    • 한국전기화학회:학술대회논문집
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    • 한국전기화학회 2003년도 전지기술심포지움
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    • pp.153-168
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    • 2003
  • Polymer electrolytes - solid polymeric membranes with dissolved salts - are being intensively studied for use in all-solid-state lithium-metal-polymer consumer electronic device. The low ionic conductivity at room temperature of existing polymer electrolytes, however, has seriously hindered the development of such batteries for many applications. The incorporation of salts molten at room temperature (room temperature ionic liquids or RTILs) into polymer electrolytes may be the necessary solution to overcoming the inherent ionic conductivity limitations of 'dry' polymer electrolytes.

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Electrochemical Characterization of Lithium Polyelectrolyte Based on Ionic Liquid

  • Cha, E.-H.;Lim, S.-A.;Kim, D.-W.;Choi, N.-S.
    • 전기화학회지
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    • 제12권3호
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    • pp.271-275
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    • 2009
  • Five novel lithium polyelectrolyte-ionic liquid systems, using poly (lithium 2-acrylamido-2-methyl propanesulfonate; PAMPSLi) were prepared and their electrochemical properties were measured. The ionic conductivity of the PAMPSLi/1-ethyl-3-methylimidazolium tricyano methanide (emImTCM) system was exhibited high conductivity (1.28 $\times$ $10^{-3}$ $S/cm^{-1}$). The high conductivity and low viscosity of PAMPSLi/emImTCM system is due to the high flexibility of imidazolium cation and dissociation of lithium cation from the polymer chains. The PAMPSLi/N,N-dimethyl-N-propyl-Nbutylammonium tricyanomethanide ($N_{1134}TCM$) and PAMPSLi/N, N-dimethyl-N-propyl-N-butylammonium dicyanamide ($N_{1134}DCA$) systems showed fairly high conductivity (6.3 $\times$ $10^{-4}$ $S/cm^{-1}$, 6.0 $\times$ 10.4 S/cm.1). PAMPSLi/Trihexyl (tetradecyl) phosphonium bis (trifluoromethane sulfonyl) amide ($P_{66614}TFSA$) exhibited low conductivity (2.22 $\times$ $10^{-5}$ $Scm^{-1}$) and thermally stable over 400$^{\circ}C$.

Improvement of Mechanical and Electrical Properties of Poly(ethylene glycol) and Cyanoresin Based Polymer Electrolytes

  • Oh Kyung-Wha;Choi Ji-Hyoung;Kim Seong-Hun
    • Fibers and Polymers
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    • 제7권2호
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    • pp.89-94
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    • 2006
  • Ionic conductivity and mechanical properties of a mixed polymer matrix consisting of poly(ethylene glycol) (PEG) and cyanoresin type M (CRM) with various lithium salts and plasticizer were examined. The CRM used was a copolymer of cyanoethyl pullulan and cyanoethyl poly(vinyl alcohol) with a molar ratio of 1:1, mixed plasticizer was ethylene carbonate (EC) and propylene carbonate (PC) at a volume ratio of 1:1. The conductive behavior of polymer electrolytes in the temperature range of $298{\sim}338\;K$ was investigated. The $PEG/LiClO_4$ complexes exhibited the highest ionic conductivity of ${\sim}10^{-5}S/cm$ at $25^{\circ}C$ with the salt concentration of 1.5 M. In addition, the plasticized $PEG/LiClO_4$ complexes exhibited improvement of ionic conductivity. However, their complexes showed decreased mechanical properties. The improvement of ionic conductivity and mechanical properties could be obtained from the polymer electrolytes by using CRM. The highest ionic conductivity of PEG/CRM/$LiClO_4$/(EC-PC) was $5.33{\time}10^{-4}S/cm$ at $25^{\circ}C$.

Investigation of Lithium Transference Number in PMMA Composite Polymer Electrolytes Using Monte Carlo (MC) Simulation and Recurrence Relation

  • Koh, Renwei Eric;Sun, Cha Chee;Yap, Yee Ling;Cheang, Pei Ling;You, Ah Heng
    • Journal of Electrochemical Science and Technology
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    • 제12권2호
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    • pp.217-224
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    • 2021
  • In this study, Monte Carlo (MC) simulation is conducted with recurrence relation to study the effect of SiO2 with different particle size and their roles in enhancing the ionic conductivity and lithium transference number of PMMA composite polymer electrolytes (CPEs). The MC simulated ionic conductivity is verified with the measurements from Electrochemical Impedance Spectroscopy (EIS). Then, the lithium transference number of CPEs is calculated using recurrence relation with the MC simulated current density and the reference transference number obtained. Incorporation of micron-size SiO2 (≤10 ㎛) fillers into the mixture improves the ionic conductivity from 8.60×10-5 S/cm to 2.35×10-4 S/cm. The improvement is also observed on the lithium transference number, where it increases from 0.088 to 0.3757. Furthermore, the addition of nano-sized SiO2 (≤12 nm) fillers further increases the ionic conductivity up towards 3.79×10-4 S/cm and lithium transference number of 0.4105. The large effective surface area of SiO2 fillers is responsible for the improvement in ionic conductivity and the transference number in PMMA composite polymer electrolytes.

이온성 액체를 함유한 고분자 겔 전해질의 특성연구 (Characterization of Ionic Liquid Contained Polymer Gel Electrolyte)

  • 류상욱;송의환
    • 폴리머
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    • 제32권1호
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    • pp.85-89
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    • 2008
  • 이온성 액체인 N-methoxymethyl-N-methylpyrrolidium bis(trifluoro-methansulfonyl)imide (MPSI)를 첨가제로 함유하는 acrylate 계열의 단량체를 다관능기형 acrylate 가교제와 함께 carbonate 용매에서 중합, 겔형의 고분자 전해질을 합성하였다. 고분자 전해질의 이온전도성은 고분자의 함량, 가교제의 종류, 이온성 액체의 함량에 따라 측정되었으며, 인장강도를 조사하여 고분자 및 이온성 액체의 함량이 기계적 물성에 미치는 영향을 파악하였다. 그 결과 성분의 최적화는 고분자 함량 15 wt%, 이온성액체 30 wt% 그리고 5 wt%의 가교제를 함유한 겔 전해액으로 달성되었고, 0.5 MPa의 기계적 물성과 0.8 mS/cm의 우수한 상온 이온 전도도를 나타내었다.

염료감응형 태양전지에서의 고분자 전해질 종류에 따른 이온전도도와의 상호관계 (The correlation between ionic conductivity and cell performance with various compositions of polymer electrolyte in dye-sensitized solar cells)

  • 차시영;김수진;이용건;강용수
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2007년도 추계학술대회 논문집
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    • pp.306-308
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    • 2007
  • Poly(ethylene glycol) dimethyl ether (PEGDME)/fumed silica/ 1-methyl -3-propylimidazolium iodide (MPII)/$I_2$ mixtures were used as polymer electrolytes in solid state dye-sensitized solar cells (DSSCs). The contents of MPII were changed and the concentration of $I_2$ was fixed at 0.1 mole% with respect to the MPII. The maximum ionic conductivity was obtained at [EG]:[MPII]:[$I_2$]=10:1.5:0.15. It was supposed that the maximum of ionic conductivities would match with that of cell efficiencies, if the ionic conductivity is a rate determining step in the sol id state DSSCs. However, the maximum composition did not show the maximum solar cell performance, indicating the mismatch between ionic conductivity and cell performance. This suggests that the ionic conductivity may not be the rate controlling step in determining the cell efficiency in these experimental conditions, whereas other parameters such as the electron recombination might play an important role. Thus, we tried to modify the surface of the $TiO_2$ particles by coating a thin metal oxide such as $Al_2O_3$ or $Nb_2O_5$ layer to prevent electron recombination. As a result, the maximum of the cell efficiency was shifted to that of the ionic conductivity. The peak shifts were also attempted to be explained by the diffusion coefficient and the lifetime of electrons in the $TiO_2$ layer.

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Effect of Li on the Ionic Conductivity and Leaching in Simulated Borosilicate Glasses

  • 이종규;김종구;김승수;지광용;전관식
    • Bulletin of the Korean Chemical Society
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    • 제18권7호
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    • pp.740-743
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    • 1997
  • The ionic conductivity of several simulated borosilicate glasses was measured in the temperature range 150-600℃ in air. Leaching experiments were also carried out using Soxhlet apparatus at 100 ℃ for 7 days. As Li+ ion increased in simulated borosilicate glasses, both the ionic conductivity and leaching rate increased. The activation energy in the ionic conduction of the simulated borosilicate glasses was 1.38-1.45 eV in the high temperature region and 0.93-1.1 eV in the low temperature region.

불포화 폴리에스터의 경화에 따른 유전특성 연구 (Dielectric Characterization of Unsaturated Polyester Curing)

  • 오경성;김홍경;김명덕;남재도
    • 폴리머
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    • 제26권6호
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    • pp.728-736
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    • 2002
  • The thermal and dielectric properties of unsaturated polyester resin system during cure were analyzed under Isothermal conditions. Both $varepsilon$′ and $varepsilon$" decreased and dipole relaxation was observed under isothermal conditions during cure. The ionic conductivity decreased linearly with the conversion according to the Kienle-Rate equation (ln($varepsilon$"$_{ionic}$we$_{0}$)=C$_{r}$$alpha$+C$_{0}$) up to $alpha$=0.15, after which it aparted from the relationship due to the entanglement of polymer chains. The effect of ionic conductivity was revealed to be larger than that of dipole motion during the whole cure through the electrical modulus analysis. Although dielectric motion was analyzed with Debye model, it was observed only at a narrow time region of middle stage of cure. In order to estimate the dielectric properties during the whole cure, the Havriliak-Negami model was considered and modified with the strong effect of ionic conductivity. The changes of $varepsilon$′ and $varepsilon$" were well estimated with this modified Havriliak-Negami model.

Dependence of the lithium ionic conductivity on the B-siteion substitution in $(Li_{0.5}La_{0.5})Ti_{1-x}M_xO_3$

  • Kim, Jin-Gyun;Kim, Ho-Gi
    • E2M - 전기 전자와 첨단 소재
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    • 제11권11호
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    • pp.9-17
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    • 1998
  • The dependence of the ionic conductivity on the B-site ion substitution in (Li0.5La0.5)Ti1-xMxO3 (M=Sn, Zr, Mn, Ge) system has been studied. Same valence state and various electronic configuration and ionic radius of Sn4+, Zr4+, Mn4+ and Ge4+(4d10(0.69$\AA$), 4p6(0.72$\AA$), 3d10(0.54$\AA$) and 3d3(0.54$\AA$), respectively) induced the various crystallographic variaton with substitutions. So it was possibleto investigate the crystallographic factor which influence the ionic conduction by observing the dependence of the conductivity on the crystallographic factor which influence the ionic conduction by observing the dependence of the conductivity on the crystallographic variations. We found that the conductivity increased with decreasing the radii of B-site ions or vice versa and octahedron distortion disturb the ion conduction. The reason for this reciprocal proportion of conductivity on the radius of B-site ions has been examined on the base of the interatomic bond strength change due to the cation substitutions. The results were good in agreement with the experimental results. Therefore it could be concluded that the interatomic bond strength change due to the cation substitutions may be the one of major factors influencing the lithium ion conductivity in perovskite(Li0.5La0.5) TiO3system.

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