A high-performance polymer composite electrolyte embedded with ionic liquid for all solid lithium based batteries operating at ambient temperature

You, Duck-Jae,Yin, Zhenxing,Ahn, Yong-keon,Cho, Sanghun,Kim, Hyunjin,Shin, Dalwoo,Yoo, Jeeyoung,Kim, Youn Sang Elsevier 2017 Journal of industrial and engineering chemistry Vol.52 No.-

<P><B>Abstract</B></P> <P>A novel polymer composite electrolyte for lithium-based battery operating at room temperature was introduced. The proposed polymer composite electrolyte consisted of electrolyte using a 3-D cross-linked polymer matrix, which is synthesized with polyethylene glycol (PEG) and 3-glycidoxypropyltrimethoxysilane (GPTMS), and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMITFSI) as a Li-ion transport medium. The proposed polymer composite electrolyte shows a high ionic conductivity of 35×10<SUP>−2</SUP> mScm<SUP>−1</SUP> and high decomposition temperature of 250°C with a 3-D cross-linked polymer matrix. The EMITFSI mass ratio is 1:0.7 at room temperature. In addition, when polymer composite electrolyte is applied to the solid battery consisting of Li metal as an anode and LiFePO<SUB>4</SUB> as a cathode, it can be operated at room temperature with a high specific capacity of 75.8mAh/g at 0.1C rate. Furthermore, the battery with a structure of Li/polymer composite electrolyte/LiFePO<SUB>4</SUB> also has excellent capacity retention.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Polymer composite electrolytes were composed with the 3-D cross-linked polymer matrix and EMITFSI. </LI> <LI> The suggested polymer composite electrolyte was thermally stable up to 250°C. </LI> <LI> Ionic conductivity was strongly increased by addition of EMITFSI to polymer composite electrolyte. </LI> <LI> Polymer composite electrolyte achieved a high ionic conductivity of 35×10<SUP>−2</SUP> mScm<SUP>−1</SUP> at room temperature. </LI> <LI> The discharge specific capacity of Li/polymer composite electrolyte/LiFePO<SUB>4</SUB> battery was increased to 75.8mAh/g at room temperature. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P> <P>Polymer composite electrolyte embedding ionic liquid to fabricate the high-performance all-solid-state Li-battery operating at room temperature. The proposed electrolyte shows a high ionic conductivity 35×10<SUP>−2</SUP> mScm<SUP>−1</SUP>. When polymer composite electrolyte is applied to the battery, it can be operated at room temperature.</P>

과불소화된 아크릴레이트 가교제로 제조된 직접 가교형 겔 고분자 전해질의 전기화학적 특성

오시진,심효진,김동욱,이명훈,이창진,강영구,Oh, Si-Jin,Shim, Hyo-Jin,Kim, Dong-Wook,Lee, Myong-Hoon,Lee, Chang-Jin,Kang, Yong-Ku 한국전기화학회 2010 한국전기화학회지 Vol.13 No.2

본 연구에서는 organophosphate를 기반으로 한 과불소화된 아크릴레이트 가교제를 사용하여 제조한겔 고분자 전해질의 이온 전도도 및 전기화학적 특성을 평가하였다. 과불소화된 아크릴레이트 가교제를 사용하여 만든 겔 고분자 전해질은 액체전해질의 함량이 최대 97 wt%까지 안정한 겔 상태를 유지하였다. 본 연구에서 제조한 겔 고분자 전해질의 이온전도도는 $30^{\circ}C$에서 $1.0\;{\times}\;10^{-2}\;S/cm$의 값을 가졌다. 또한 전기화학적 안정성 테스트에서도 약 4.5V로 이상까지 산화에 의한 열화가 없이 안정하였다. 합성된 겔고분자 전해질을 리튬이온 고분자 전지에 적용하여 그 활용성을 평가하였다. 양극으로는 $LiCoO_2$를 사용하였으며 음극으로는 카본을 사용하였다. 이렇게 만든 리튬이온 고분자 전지는 0.1C에서 136.11 mAh/g의 용량으로 이론용량과 거의 비슷한 값을 나타내었으며, 2C 방전에서도 초기 용량의 91%를 유지하였다. 또한 500번의 충방전 후에도 초기 용량의 70%정도의 용량을 유지하였다. The gel polymer electrolyte(GPE) were prepared by in-situ thermal cross-linking reaction of homogeneous precursor solution of perfluorinated phosphate-based cross-linker and liquid electrolyte. Ionic conductivities and electrochemical properties of the prepared gel polymer electrolyte with the various contents of liquid electrolytes and perfluorinated organophosphate-based cross-linker were examined. The stable gel polymer electrolyte was obtained up to 97 wt% of the liquid electrolyte. Ionic conductivity and electrochemical properties of the gel polymer electrolytes with the various chain length of perfluorinated ethylene oxide and different content of liquid electrolytes were examined. The maximum ionic conductivity of liquid electrolyte was measured to be $1.02\;{\times}\;10^{-2}\;S/cm$ at $30^{\circ}C$ using the cross-linker($PFT_nGA$). The electrochemical stability of the gel polymer electrolyte was extended to 4.5 V. The electrochemical performances of test cells composed of the resulting gel polymer electrolyte were also studied to evaluate the applicability on the lithium polymer batteries. The test cell carried a discharge capacity of 136.11mAh/g at 0.1C. The discharge capacity was measured to be 91% at 2C rate. The discharge capacity decreased with increase of discharge rate which was due to the polarization. After 500th charge/discharge cycles, the capacity of battery decreased to be 70% of the initial capacity.

Enhancement of Mechanical Property and Ionic Conductivity of Chitosan-Based Solid Polymer Electrolytes using Carbon nanotubes as Fillers

김재석,임종국 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1

As the spread of smart devices becomes more popular, there is an increasing interest in wearable devices as a whole, not as a partly flexible device. In order to apply this, much research has been carried out to use flexible solid polymer electrolyte rather than liquid electrolyte. However, solid polymer electrolytes have low ionic conductivity and are difficult to apply to smart devices. There have been many studies to enhance the ionic conductivity and physical stability of polymer electrolytes by adding various plasticizers and nanowires in order to secure them. In this study, silver nanowire was synthesized and used as an additive in order to increase physical stability and ionic conductivity in chitosan polymer electrolyte and For the synthesis of solid electrolytes with higher ionic conductivity, chitosan based polymer electrolytes were synthesized by replacing silver nanowires with carbon nanotubes.

염료감응 태양전지용 고분자 전해질막의 총설

이재훈,박철훈,이창수,김종학 한국막학회 2019 멤브레인 Vol.29 No.2

염료감응형 태양전지는 지속 가능한 에너지원으로서 많은 관심을 받고 있다. 염료감응형 태양전지의 효율과 장기안정성은 전극 물질과 전해질에 의해 크게 영향을 받는데 본 총설에서는 전해질에 초점을 두어 서술하고자 한다. 고분자 전해질막은 염료감응형 태양전지에서 기존의 액체 전해질을 대체하기 위한 대안으로 제시되어 왔다. 기존의 액체 전해질은 높은 효율을 나타낼 수 있지만 장기적인 안정성 문제와 누액 문제로 인해 고분자 전해질막에 관한 관심은 지속적으로 증가하고있으며 매년 이와 관련된 논문들이 활발히 보고되고 있다. 본 총설은 염료감응형 태양전지를 위한 고분자 전해질막의 개념과개발에 대한 간단한 설명을 다루고 있으며 고분자 매트릭스의 개질, 유-무기 가소제 및 이온성 액체와 같은 첨가제의 도입에따른 염료감응형 태양전지의 효율과 전기화학적 특성에 대해서도 최근의 연구들이 정리되어 있다. Dye-sensitized solar cells (DSSCs) have attracted great attention as sustainable energy devices. The efficiency and long-term stability of DSSCs are greatly influenced by electrode materials and electrolytes. In this review, we focused on the electrolytes of DSSCs. Polymer electrolyte membranes have been proposed as an alternative to conventional liquid electrolytes in DSSCs. Conventional liquid electrolytes can exhibit a high efficiency, but due to some problems such as poor long-term stability of device and leakage of liquid, much interest in polymer electrolyte membranes continues to rise and the papers on polymer electrolytes membranes have been extensively reported recently. This review covers the concept and development of polymer electrolyte membranes for DSSCs, and discusses the efficiency and electrochemical properties of DSSCs, highlighting the modification of polymer matrix, the introduction of additives such as organic-inorganic plasticizers and ionic liquids.

Improvement in Long-Term Stability and Photovoltaic Performance of UV Cured Resin Polymer Gel Electrolyte for Dye-Sensitized Solar Cell

Park, Geun Woo,Hwang, Chul Gyun,Jung, Jae Won,Jung, Young Mee Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.12

We introduced a new UV-cured resin polymer gel as an electrolyte for dye-sensitized solar cells (DSSCs) that is cured with UV irradiation to form a thin film of UV-cured resin polymer gel in the cells. The gel film was characterized and its potential for use as an electrolyte in DSSCs was investigated. This new UV-cured resin polymer gel was successfully applied as a gel polymer electrolyte in DSSCs overcoming the problems associated with the liquid electrolytes in typical DSSCs. The effect of ${\gamma}$-butylrolactone (GBL) on the long-term stability and photovoltaic performance in DSSCs using this UV-cured resin polymer gel electrolyte was also investigated. The results of the energy conversion efficiency, ionic conductivity and Raman spectra of the UV-cured resin polymer gel electrolyte with the addition of 6 wt % GBL to the UV-cured resin polymer electrolyte showed good long-term stability and photovoltaic performance for the DSSCs with the UV-cured polymer gel electrolyte.

Improvement in Long-Term Stability and Photovoltaic Performance of UV Cured Resin Polymer Gel Electrolyte for Dye-Sensitized Solar Cell

Geun Woo Park,Chul Gyun Hwang,Jae Won Jung,정영미 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.12

We introduced a new UV-cured resin polymer gel as an electrolyte for dye-sensitized solar cells (DSSCs) that is cured with UV irradiation to form a thin film of UV-cured resin polymer gel in the cells. The gel film was characterized and its potential for use as an electrolyte in DSSCs was investigated. This new UV-cured resin polymer gel was successfully applied as a gel polymer electrolyte in DSSCs overcoming the problems associated with the liquid electrolytes in typical DSSCs. The effect of γ-butylrolactone (GBL) on the long-term stability and photovoltaic performance in DSSCs using this UV-cured resin polymer gel electrolyte was also investigated. The results of the energy conversion efficiency, ionic conductivity and Raman spectra of the UVcured resin polymer gel electrolyte with the addition of 6 wt % GBL to the UV-cured resin polymer electrolyte showed good long-term stability and photovoltaic performance for the DSSCs with the UV-cured polymer gel electrolyte.

Poly[(ethylene glycol) diacrylate]-Poly(vinylidene fluoride) 전해질을 이용한 전기 이중층 캐패시터의 전기화학적 특성

양천모 ( Chun Mo Yang ),이중기 ( Joong Kee Lee ),조원일 ( Won Il Cho ),조병원 ( Byung Won Cho ),주재백 ( Jeh Beck Ju ),유관표 ( Kwan Pyo Yoo ),임병오 ( Byung O Rim ) 한국공업화학회 2002 공업화학 Vol.13 No.8

자외선 경화법으로 제조한 PEGDA-PVdF 젤상 고분자 전해질을 전기이중층캐패시터에 적용하였고, 액상 유기 전해질을 이용한 전기이중층캐패시터와 전기화학적 특성을 비교 조사하였다. 자외선 경화법으로 제조된 젤상 고분자 전해질[GPE:poly[(ethylene glycol) diacrylate]-poly(vinylidene fluoride) blend]을 이용한 전기이중층캐패시터의 경우, 비축전용량이 120 F/g으로 액상 유기 전해질 [LOE:1 M LiPF_6/EC:DMC:EMC (1:1:1 volume ratio)]을 이용한 전기이중층캐패시터의 비축전용량인 110 F/g보다 우수하였고, 100회 충방전 후에도 초기 비축전용량대비 92% 이상 유지하는 우수한 싸이클 특성을 나타내었으며 3.7 Ω의 낮은 ESR(equivalent series resistance)을 보여주었다. Cyclic voltammetry 분석 결과에서 보면 액상 유기 전해질과 젤상 고분자 전해질을 이용한 모든 전기이중층캐패시터에서 2.5 V까지 전해질의 분해 없이 전기화학적으로 안정하였고, 산화와 환원과 관련된 전류값 또한 관찰되지 않았다. 젤상 고분자 전해질을 이용한 전기이중층캐패시터의 경우에서 직사각형 모양의 이상적인 전기이중층캐패시터의 특성과 49 ㎂의 낮은 누설 전류값을 나타내었다. 자가방전 특성 결과, 젤상 고분자 전해질을 이용한 전기이중층캐패시터의 경우 2.5 V의 정전압 충전 시 OCV(open circuit voltage) 상태에서 100 h 경과 후 1.76 V의 전압을 유지하고 있어 0.25 V의 액상 유기 전해질을 이용한 전기이중층캐패시터보다 매우 우수함을 확인하였다. Poly[(ethylene glycol) diacrylate] (PEGDA)-poly(vinylidene fluoride) (PVdF) gel polymer was employed as an electrolyte for electric double layer capacitor (EDLC) and compared its electrochemical characteristics with that of liquid organic electrolyte. The used organic electrolyte was 1 mole of lithium hexafluorophosphate (LiPF_6) salt containing in the solvent mixture of ethylene carbonate(EC):dimethyl carbonate(DMC):ethylmethyl carbonate(EMC)(1:1:1 volume ratio). The specific capacitance of EDLC with gel polymer electrolyte showed 120 F/g, which was superior to that of 110 F/g with liquid organic electrolyte. Good cyclability was observed for gel polymer electrolyte of EDLC. The 92% of initial specific capacitance was retained after 100 cycles of charge-discharge runs. Equivalent series resistance of 3.7 Ω of the EDLC with gel polymer electrolyte was lower than that of EDLC with liquid organic electrolyte. The EDLC with gel polymer electrolyte exhibited rectangular cyclic voltammogram of ideal EDLC in operating voltage range of 0∼2.5 V and low leakage current of 49 ㎂. Voltage drop from self-discharge was low for gel polymer electrolyte. The 29.6% of initial voltage decreased for gel polymer electrolyte, but significantly decreased to 99% for liquid organic electrolyte. The good retentivity with gel polymer electrolyte possible comes from the difference in viscosity compared with that of liquid organic electrolyte.

Charge Transport Properties of Polymer Blends in Organic Electrolyte-Gated Transistors

배온유,김선주 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0

Charge transport properties of materials organic and polymer semiconductors are one of the most critical factors for wide-spread commercialization of organic electronics. In this work, we have investigated charge transport properties of polymer blends under high chargecarrier density by using a platform of organic electrolyte-gated transistors (OEGTs). Polymer blends used in this study consist of both crystalline organic semiconductors and amorphous polymers. Amorphous polymer can act as a structural matrix and charge transporting bridges, depending on their structures and blend morphology. With a high-capacity gate insulator based on polymer ion gels of the PVDFHFP/[ EMIM][TFSI] system, we are able to operate the polymer-blend OEGTs at low voltages and a high carrier density. Device-level investigation of OEGTs based on the blends are also presented.

Solid polymer electrolytes containing poly(ethylene glycol) and renewable cardanol moieties for all-solid-state rechargeable lithium batteries

Baik, J.H.,Kim, D.G.,Shim, J.,Lee, J.H.,Choi, Y.S.,Lee, J.C. IPC Science and Technology Press 2016 Polymer Vol.99 No.-

A series of self-crosslinkable polymers composed of different amounts of ionic conducting units (poly(ethylene glycol) methyl ether methacrylate) and crosslinkable units (2-hydroxy-3-cardanylpropyl methacrylate) obtained from a renewable resource, cardanol, were prepared for application to solid polymer electrolytes. Free-standing solid polymer electrolytes were prepared by mixing the polymers with lithium bis(trifluoromethanesulfonyl)imide followed by UV irradiation to induce reaction of the double bonds in the cardanol moiety, forming the cross-linked structures. The ionic conductivity of the solid crosslinked polymer electrolyte prepared from the polymers containing 8 mol% of the cross-linkable cardanol monomeric units was 1.9 x 10<SUP>-4</SUP> S cm<SUP>-1</SUP> at 60 <SUP>o</SUP>C, which is close to those of poly(poly(ethylene glycol) methyl ether methacrylate) in the waxy state. The all-solid-state lithium battery prepared using this solid polymer electrolyte without a separator exhibited stable cell operation, showing 81.4% of capacity retention after 100 charge-discharge cycles, and demonstrating that the self-crosslinkable polymer from the renewable resource is suitable for high-temperature and high-voltage lithium secondary battery applications.

Effects of plasticizer and nanofiller on the dielectric dispersion and relaxation behaviour of polymer blend based solid polymer electrolytes

R.J. Sengwa,Priyanka Dhatarwal,Shobhna Choudhary 한국물리학회 2015 Current Applied Physics Vol.15 No.2

Solid polymer electrolytes consisted of poly(ethylene oxide) (PEO) and poly(methyl methacrylate) (PMMA) blend (50:50 wt/wt%) with lithium triflate (LiCF3SO3) as a dopant ionic salt at stoichiometric ratio [EO + (C=O)]:Li+ = 9:1, poly(ethylene glycol) (PEG) as plasticizer (10 wt%) and montmorillonite (MMT) clay as nanofiller (3 wt%) have been prepared by solution cast followed by melt-pressing method. The Xeray diffraction study infers that the (PEO-PMMA)-LiCF3SO3 electrolyte is predominantly amorphous, but (PEO-PMMA)-LiCF3SO3-10 wt% PEG electrolyte has some PEO crystalline cluster, whereas (PEO-PMMA)-LiCF3SO3-10 wt% PEG-3 wt% MMT electrolyte is an amorphous with intercalated and exfoliated MMT structures. The complex dielectric function, ac electrical conductivity, electric modulus and impedance spectra of these electrolytes have been investigated over the frequency range 20 Hz to 1 MHz. These spectra have been analysed in terms of the contribution of electrode polarization phenomenon in the low frequency region and the dynamics of cations coordinated polymer chain segments in the high frequency region, and also their variation on the addition of PEG and MMT in the electrolytes. The temperature dependent dc ionic conductivity, dielectric relaxation time and dielectric strength of the plasticized nanocomposite electrolyte obey the Arrhenius behaviour. The mechanism of ions transportation and the dependence of ionic conductivity on the segmental motion of polymer chain, dielectric strength, and amorphicity of these electrolytes have been explored. The room temperature ionic conductivity values of the electrolytes are found ~10-5 S cm-1, confirming their use in preparation of allsolid- state ion conducting devices.