• Journal of Electrochemical Science and Technology
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• v.10 no.3
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• pp.294-301
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• 2019

The quasi-solid-state hybrid electrolytes were synthesized by chemical cross-linking reaction of methacrylate-functionalized $SiO_2$ ($MA-SiO_2$) and tetra (ethylene glycol) diacrylate in aqueous electrolyte. A quasi-solid-state electrolyte synthesized by 6 wt.% $MA-SiO_2$ exhibited a high ionic conductivity of $177mS\;cm^{-1}$ at room temperature. The electrochemical $H_2$ sensor assembled with quasi-solid-state electrolyte showed relatively fast response and high sensitivity for hydrogen gas at ambient temperature, and exhibited better durability and stability than the liquid electrolyte-based sensor. The simple construction of the sensor and its sensing characteristics make the quasi-solid-state hydrogen sensor promising for practical application.

• Journal of Electrochemical Science and Technology
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• v.8 no.3
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• pp.257-264
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• 2017

A polymeric ionic liquid, poly(1-methyl 3-(2-acryloyloxypropyl) imidazolium iodide) (PMAPII), was synthesized as a single-iodide-ion-conducting polymer and employed in a gel polymer electrolyte. Gel polymer electrolytes prepared from iodine, 4-tert-butylpyridine, ${\gamma}$-butyrolactone, and PMAPII were applied in quasi-solid-state dye-sensitized solar cells (DSSCs). The addition of 16 wt.% PMAPII provided the most favorable environment, striking a compromise between the iodide ion concentration and the ionic mobility, which resulted in the highest conversion efficiency of the resulting DSSCs. The quasi-solid-state DSSC assembled with the optimized gel polymer electrolyte exhibited a relatively high conversion efficiency of 7.67% under AM 1.5 illumination at $100mA\;cm^{-2}$ and better stability than that of the DSSC with a liquid electrolyte.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.484.2-484.2
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• 2014

There are many efforts to improving the power conversion efficiencies (PCEs) of dye-sensitized solar cells (DSCs). Although DSCs have a low production cost, their low PCE and low thermal stability have limited commercial applications. This study describes the preparation of a novel multifunctional polymer gel electrolyte in which a cross-linking polymerization reaction is used to encapsulate $TiO_2$ nanoparticles toward improving the power conversion efficiency and long-term stability of a quasi-solid state DSC. A series of liquid junction dye-sensitized solar cells (DSCs) was fabricated based on polymer membrane encapsulated dye-sensitized $TiO_2$ nanoparticles, prepared using a surface-induced cross-linking polymerization reaction, to investigate the dependence of the solar cell performance on the encapsulating membrane layer thickness. The ion conductivity decreased as the membrane thickness increased; however, the long term-stability of the devices improved with increasing membrane thickness. Nanoparticles encapsulated in a thick membrane (ca. 37 nm), obtained using a 90 min polymerization time, exhibited excellent pore filling among $TiO_2$ particles. This nanoparticle layer was used to fabricate a thin-layered, quasi-solid state DSC. The thick membrane prevented short-circuit paths from forming between the counter and the $TiO_2$ electrode, thereby reducing the minimum necessary electrode separation distance. The quasi-solid state DSC yielded a high power conversion efficiency (7.6/8.1%) and excellent stability during heating at $65^{\circ}C$ over 30 days. These performance characteristics were superior to those obtained from a conventional DSC (7.5/3.5%) prepared using a $TiO_2$ active layer with the same thickness. The reduced electrode separation distance shortened the charge transport pathways, which compensated for the reduced ion conductivity in the polymer gel electrolyte. Excellent pore filling on the $TiO_2$ particles minimized the exposure of the dye to the liquid and reduced dye detachment.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.117.1-117.1
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• 2011

We have demonstrated Forst-type resonance energy transfer (FRET) in the quasi-solid type dye-sensitized solar cells between organic fluorescence materials as an energy donor doped in polymeric gel electrolyte and ruthenium complex as an energy acceptor on surface of $TiO_2$. The strong spectral overlap of emission/absorption of energy donor and acceptor is required to get high FRET efficiency. The judicious choice of energy donor allows the enhancement of light harvesting characters of energy acceptor in quasi-solid dye sensitized solar cells which increase the power conversion efficiency. The enhanced light harvesting effect by the judicious choice/design of the fluorescence materials and sensitizing dyes permits the enhancement of photovoltaic performance of DSSC.

• Rubber Technology
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• v.13 no.1
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• pp.1-9
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• 2012

Click chemistry had enjoyed a wealthy decade after it was introduced by K.B.Sharpless and his co-worker on 2001. Since there is no optimized method for synthesis of click polymer, therefore, this paper introduced three click reaction methods such as catalyst, non-catalyst and azide-end capping for fluorene-based functional click polymers. The obtained polymers have reasonable molecular weight with narrow PDI. The polymers are thermally stable and almost emitted blue light emission. The synthesized fluorene-based functional click polymers were characterized to compare the effect of click reaction methods on polymer electro-optical properties as well as device performance on quasi-solid-state dye sensitized solar cells (DSSCs) applications. The DSSCs with configuration of $SnO_2:F/TiO_2/N719$ dye/quasi-solid-state electrolyte/Pt devices were fabricated using these click polymers as a solid-state electrolyte components. Among the devices, the catalyzed click polymer composed device exhibited a high power conversion efficiency of 4.62% under AM 1.5G illumination ($100mW/cm^2$).These click polymers are promising materials in device application and $Cu^I$-catalyst 1, 3-dipolar cycloaddition click reaction is an efficient synthetic methodology.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1130-1132
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• 2009

We propose a novel way for enhancement of efficiency on a quasi solid-state dye-sensitized solar cell (DSSC). It contained gel type electrolyte mixing the liquid crystal (LC) of specific concentration and applied voltage for alignment of the LC. Aligned LC is supported charge transfer inside electrolyte and efficiency is increased in DSSC. We made a quasi solid-state DSSC which applied DC voltage or not and have measured the power conversion efficiency (PCE) and the fill factor. From measurement, we obtain high performances in case of cell applied voltage compare to reference cell.

• Journal of the Korean Electrochemical Society
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• v.24 no.4
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• pp.100-105
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• 2021

Recently, all-solid-state batteries have attracted much attention to improve safety of rechargeable lithium batteries, but the solid-state batteries of conductive ceramics or solid polymer electrolytes show poor electrochemical properties because of several problems such as high interfacial resistance and undesired reactions. To solve the problems of the reported all-solid-state batteries, a hybrid solid electrolyte is suggested, in this study, NASICON-type nanoparticle Li_1.5Al_0.5Ti_1.5P₃O₁₂ (LATP) conductive ceramic, PVdF-HFP, and a carbonate-based liquid electrolyte were composited to prepare a quasi-solid electrolyte. The hybrid solid electrolyte has a high voltage stability of 5.6 V and shows an suppress effect of lithium dendrite growth in the stripping-plating test. The LiNi_0.83Co_0.11Mn_0.06O₂ (NCM811)-based battery with the hybrid solid electrolyte exhibits a high discharge capacity of 241.5 mAh/g at a high charge-cut-off voltage of 4.8V and stable electrochemical reaction. The NCM811-based battery also shows 139.4 mAh/g discharge capacity without short circuit or explosion at 90℃. Therefore, the LATP-based hybrid solid electrolyte can be an effective solution to improve the safety and electrochemical properties of rechargeable lithium batteries.

• Journal of Electrochemical Science and Technology
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• v.15 no.2
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• pp.261-267
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• 2024

An unconventional fabrication technique of nanoelectrode was developed using atomic force microscopy (AFM) and hydrogel. Until now, the precise control of electroactive area down to a few nm² has always been an obstacle, which limits the wide application of nanoelectrodes. Here, the nanometer-sized contact between the boron-doped diamond (BDD) as conductive AFM tip and the agarose hydrogel as solid electrolyte was well governed by the feedback amplitude of oscillation in the non-contact mode of AFM. Consequently, this low-cost and feasible approach gives rise to new possibilities for the fabrication of nanoelectrodes. The electroactive area controlled by the set point of AFM was investigated by cyclic voltammetry (CV) of the ferrocenmethanol (FcMeOH) combined with quasi-solid agarose hydrogel as an electrolyte. Single copper (Cu) nanoparticle was deposited at the apex of the AFM tip using this platform whose electrocatalytic activity for nitrate reduction was then investigated by CV and Field Emission-Scanning Electron Microscopy (FE-SEM), respectively.

• Macromolecular Research
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• v.16 no.5
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• pp.424-428
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• 2008

We prepared an ionic gel polymer electrolyte for dye-sensitized solar cells (DSSCs) without leakage problem. Triiodide compound (BTDI) was synthesized by the reaction of benzene tricarbonyl trichloride with diethylene glycol monotosylate and subsequent substitution of tosylate by iodide using NaI. Bisimidazole was prepared by the reaction of imidazole with the triethylene glycol ditosylate under strongly basic condition provided by NaH. BTDI and bisimidazole dissolved in an ionic liquid were injected into the cells and permeated into the $TiO_2$ nanopores. In situ crosslinking was then carried out by heating to form a network structure of poly(imidazolium iodide), thereby converting the ionic liquid electrolytes to a gel or a quasi-solid state. A monomer (BTDI and bisimidazole) concentration in the electrolytes of as low as 30 wt% was sufficient to form a stable gel type electrolyte. The DSSCs based on the gel polymer electrolytes showed a power conversion efficiency of as high as 1.15% with a short circuit current density of $5.69\;mAcm^{-2}$, an open circuit voltage of 0.525 V, and a fill factor of 0.43.

• Korean Journal of Materials Research
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• v.29 no.2
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• pp.121-128
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• 2019

Supercapacitors are attracting much attention in sensor, military and space applications due to their excellent thermal stability and non-explosion. The ionic liquid is more thermally stable than other electrolytes and can be used as a high temperature electrolyte, but it is not easy to realize a high temperature energy device because the separator shrinks at high temperature. Here, we report a study on electrochemical supercapacitors using a composite electrolyte film that does not require a separator. The composite electrolyte is composed of thermoplastic polyurethane, ionic liquid and fumed silica nanoparticles, and it acts as a separator as well as an electrolyte. The silica nanoparticles at the optimum mass concentration of 4wt% increase the ionic conductivity of the composite electrolyte and shows a low interfacial resistance. The 5 wt% polyurethane in the composite electrolyte exhibits excellent electrochemical properties. At $175^{\circ}C$, the capacitance of the supercapacitor using our free standing composite electrolyte is 220 F/g, which is 25 times higher than that at room temperature. This study has many potential applications in the electrolyte of next generation energy storage devices.