Selection of Binder and Solvent for Solution-Processed All-Solid-State Battery

Lee, Kyulin,Kim, Sangryun,Park, Jesik,Park, Sung Hyeon,Coskun, Ali,Jung, Dae Soo,Cho, Woosuk,Choi, Jang Wook The Electrochemical Society 2017 Journal of the Electrochemical Society Vol.164 No.9

<P>All-solid-state batteries (ASSBs) are gaining prominence for their ability to overcome the intrinsic drawbacks of conventional liquid-based counterparts, such as electrolyte leakage, flammability, and limited voltage window. Nevertheless, ASSBs have so far been mainly investigated using lab-scale dry mixing processes and therefore suffer from limitation of scalability and agglomeration of active particles in the composite electrodes. Here, we report a systematic investigation on ASSBs fabricated by a solution-based casting process. By screening a wide range of binders and solvents, acrylonitrile butadiene rubber and para-xylene were a suitable binder and solvent, respectively, compatible with sulfide glass-ceramic solid electrolyte. This binder-solvent combination facilitates homogeneous dispersion of the solid electrolyte in the slurry and electrolyte layer, offering high adhesion between electrode materials and comparable lithium ionic conductivity to that of the dry mixing-based counterpart. When solution-based casting processes were adopted for both electrolyte and composite cathode (containing LiNi0.8Co0.1Mn0.1O2) layers, the solution-processed cell exhibits decent performance in rate capability and cyclability due to higher homogeneity of the electrode components, originating from the appropriate combination of solvent and binder. (C) 2017 The Electrochemical Society. All rights reserved.</P>

The optimum coating condition by response surface methodology for maximizing vapor-permeable water resistance and minimizing frictional sound of combat uniform fabric

Lee, Kyulin,Cho, Gilsoo Sage Science Press 2014 Textile Research Journal Vol. No.

<P>The objectives of this study are to investigate how the variables of the water-repellent coating condition, concentration of polyurethane (PU) and curing temperature, set up by response surface methodology, affect vapor-permeable water resistance and fabric frictional sound. Also it aims to analyze the relationship between tensile properties and the sound pressure level (SPL) of the fabric and, finally, to suggest the optimum coating condition for minimizing the fabric frictional sound and maximizing the vapor-permeable water resistance. It was observed that the higher PU concentration increased the water resistance and SPL, but decreased WVT (water vapor transmission). It was shown that higher curing temperature, the other variable of the coating condition, increased the water resistance and SPL but decreased WVT. The relationship between tensile properties and SPL was analyzed and it was found that tensile stress at break (<I>R</I> <SUP>2 </SUP>= .716) and toughness (<I>R</I> <SUP>2 </SUP>= .717) were highly related to SPL; however, tensile strain at break (<I>R</I> <SUP>2 </SUP>= .508) was not. Finally, the optimum coating condition for minimizing fabric frictional sound and maximizing vapor-permeable water resistance was obtained at the PU concentration of 60% and the curing temperature of 149.7, and the predicted SPL and WVT were 72.27 dB and 8478.85 g/m<SUP>2</SUP> 24 h, respectively. The coefficients of determination (<I>R</I> <SUP>2</SUP>) were 0.82 and 0.85, respectively, which indicate that the model fit was highly significant (<I>p</I> < 0.05).</P>

Heat Storage/Release Characteristics and Mechanical Properties of Combat Uniform Fabrics Treated with Microcapsules Containing Octadecane as Phase Change Materials

Kim, Inhwan,Lee, Kyulin,Cho, Gilsoo THE KOREAN FIBER SOCIETY 2016 FIBERS AND POLYMERS Vol. No.

Combat uniform fabric was treated with octadecane-containing microcapsules to impart thermostatic function in this study. Size and morphology of microcapsules, and quantity of octadecane in the microcapsules were investigated. Heat release and storage properties with respect to a variety of treatment conditions was also investigated. Fourier transform infrared spectrometer (FT-IR), scanning electron microscope (SEM), thermogravimetric analysis-differential thermal analysis (TGA-DTA), and differential scanning calorimeter (DSC) were used to measure the properties of treated fabrics. Tensile properties, including tensile strength and elongation at break, and toughness, were measured by universal tensile testing machine in a conditioned environment (<TEX>$20{\pm}1^{\circ}C$</TEX>, <TEX>$50{\pm}5%$</TEX> RH). Microcapsules were round-shaped and sized between 4.22 and <TEX>$4.92{\mu}m$</TEX> with thermal stability under <TEX>$110^{\circ}C$</TEX> of treatment temperature. Heat of fusion (<TEX>${\Delta}H_f$</TEX>) and heat of crystallization (<TEX>${\Delta}H_c$</TEX>) of the specimens increased along with the increase of microcapsule concentration. However, they decreased as the treatment temperature increased, at 12 % and 18 % of microcapsule concentrations. In case of specimens treated by 24 % of microcapsule concentration, <TEX>${\Delta}H_f$</TEX> and <TEX>${\Delta}H_c$</TEX> increased when specimens were cured at higher temperatures. Tensile strength of specimens decreased as treatment temperature increased. Elongation at break of all specimens decreased after treatment, but no specific tendency was observed. Toughness of all specimens exhibited a tendency of increase as concentration of microcapsules increased. Among the 9 treated specimens, specimen treated with 24 % of microcapsules and <TEX>$110^{\circ}C$</TEX> of curing temperature had the best heat storage/release and mechanical properties for combat uniform.

Response Surface Methodology for Optimizing Treatment Condition of Military Combat Uniform Fabrics with Phase Change Microcapsules to Minimize Fabric Frictional Sound and Maximize the Heat Property

Kim, Inhwan,Lee, Kyulin,Cho, Gilsoo THE KOREAN FIBER SOCIETY 2016 FIBERS AND POLYMERS Vol. No.

Response surface methodology (RSM) is a collection of statistical and mathematical techniques, used for modeling and optimization. This study aimed to suggest the optimum treatment condition for minimizing fabric frictional sound and maximizing heat storage and release properties of combat uniform fabric treated with phase change materials (PCMs). Nine treatment conditions were determined by central composite design (CCD) of RSM. The independent variables were the concentration of PCMs (<TEX>$X_1$</TEX> : 6, 12, 18, 24, 30 %) and curing temperature (<TEX>$X_2$</TEX> : 95, 100, 105, 110, <TEX>$115^{\circ}C$</TEX>). The degree of increase in sound pressure level (SPL) of the treated specimen ranged from 1.84 to 8.971 %, demonstrating that the treatment caused a fabric frictional sound to be louder. The SPL increased significantly as concentration increased by 18 % and there was no significant effect of curing temperature on SPL. According to the analysis on the relationship between tensile properties and SPL, toughness (<TEX>$R^2=.706$</TEX>) was closely related to SPL, whereas tensile strength and elongation at break were not. The optimum treatment condition for minimizing fabric frictional sound and maximizing the heat storage and heat release properties was suggested. The regression models about SPL, heat of fusion (<TEX>${\Delta}H_f$</TEX>) and heat of crystallization (<TEX>${\Delta}H_c$</TEX>) were investigated with respect to two independent variables of treatment conditions, concentration and curing temperature. The optimum treatment condition in the model was concentration of 15.9 % and the curing temperature of <TEX>$113.6^{\circ}C$</TEX>. The predicted SPL and <TEX>${\Delta}H_f$</TEX> were 63.21 dB (<TEX>$R^2=0.99$</TEX>) and 4.70 J/g (<TEX>$R^2=0.95$</TEX>) respectively.

Low Molecular Weight Spandex as a Promising Polymeric Binder for LiFePO₄ Electrodes

Lee, Yong-Hee,Min, Jaeyun,Lee, Kyulin,Kim, Sangryun,Park, Sung Hyeon,Choi, Jang Wook Wiley (John WileySons) 2017 Advanced energy materials Vol.7 No.8

신체 동작을 모사한 직물마찰음 발생장치의 개발 및 이를 이용한 직물 마찰음 평가

이규린,이유진,박해리,조길수,Lee, Kyulin,Lee, Eugene,Park, Haeli,Cho, Gilsoo 한국섬유공학회 2013 한국섬유공학회지 Vol.50 No.4

To investigate the sound generated by fabric friction, which simulates real wear conditions, a 'fabric friction sound generator', which simulates body movement was developed. Fabric sounds from three specimens were generated by the fabric sound simulator and recorded using high performance microphones. Physical sound parameters such as sound pressure level (SPL), level range (${\Delta}L$), and frequency difference (${\Delta}f$) were calculated for the fabrics. All the physical parameters (SPL, ${\Delta}L$, and ${\Delta}f$) of fabric sounds generated by the fourth-generation apparatus had lower values compared to the values obtained with the third-generation apparatus. Unlike the third-generation system, which generates fabric sounds by reciprocating friction, the fourth-generation system was designed with silicon-based arm-and-leg shaped abraders so that the levels of noise and fabric sounds generated were lower at all speeds.