• Journal of Electrochemical Science and Technology
• /
• 제7권2호
• /
• pp.179-184
• /
• 2016

The interface between the surface of a cathode material and the electrolyte gives rise to surface reactions such as solid electrolyte interface (SEI) and chemical side reactions. These reactions lead to increased surface resistance and charge transfer resistance. It is consequently necessary to improve the electrochemical characteristics by suppressing these reactions. In order to suppress unnecessary surface reactions, we coated cathode material using polypropylene (PP). The PP coating layer effectively reduced the SEI film that is generated after a 4.3 V initial charging process. By mitigating the formation of the SEI film, the PP-coated Li[(Ni_0.6Co_0.1Mn_0.3)_0.36(Ni_0.80Co_0.15Al0.05)_0.64)]O₂(NCS) electrode provided enhanced transport of Li⁺ ions due to reduced SEI resistance (R_SEI) and charge transfer resistance (R_ct). The initial charge and discharge efficiency of the PP-coated NCS electrode was 96.2 % at a current density of 17 mA/g in a voltage range of 3.0 ~ 4.3 V, whereas the efficiency of the NCS electrode was only 94.7 %. The presence of the protective PP layer on the cathode improved the thermal stability by reducing the generated heat, and this was confirmed via DSC analysis by an increased exothermic peak.

• 센서학회지
• /
• 제28권2호
• /
• pp.101-105
• /
• 2019

ZnS substrates with excellent transmittance in the mid-infrared region ($3-5{\mu}m$) were prepared using hot pressing instead of conventional chemical vapor deposition (CVD). Diamond-like carbon(DLC) was coated on either one or both sides of the ZnS substrates to improve their mechanical properties and transmittance. More specifically DLC was coated using CVD with an Ar and $C_2H_2$ mixed gas, and Ge was used as the bonding layer. During CVD, the bias voltage was fixed to 500 V and analyzed by Fourier transform infrared spectroscopy (FT-IR), nanoindenter, scanning electron microscope and energy dispersive spectrometry. Results of hardness analysis using the nanoindenter, showed that DLC coating increased from 5.9 to 17.7 GPa after deposition. The FT-IR spectroscopy results showed that, in the mid-infrared region ($3-5{\mu}m$), the average transmittance of the samples with DLC coating on one and both sides increased by approximately 6% and approximately 11.2% respectively. In conclusion, the DLC coating improved the durability and transmittance of the ZnS substrates.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
• /
• pp.221-226
• /
• 2001

Chloride diffusion effect of cement paste, freezing and thawing test, carbonation of concrete specimen were carried out using inorganic coating material. According to the chloride ions diffusion test, it is elucidated that permeability and diffusion coefficient of Cl￣ ions and apparent coefficient of coated cement paste is smaller than plain cement paste. A durability of coated concrete specimen was enhanced by the experiment result of concrete carbonation and freezing thawing test.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1998년도 추계학술대회 논문집
• /
• pp.129-132
• /
• 1998

In this paper, we have studied the effect of electron reflection on shadow mask on which tungsten oxide film is coated and have studied the variation of beam mislanding with coating thickness in CRT. We found the method to be able to control coating thicknessed and optimum coating thickness of tungsten oxide film was 1∼2$\mu\textrm{m}$. Mislanding of electron beam was reduced about 20∼48% with increasing coating thickness in CRT

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1997년도 추계학술대회 논문집
• /
• pp.465-467
• /
• 1997

The oscillating properties of quartz Crystal Microbalance(QCM) were analyzed by electrical measurement. We tried to analyze the properties of quartz crystal coated with Langmuir-Bladgett(LB) films using the frequency and resistance at resonance in the electrical equivalent circuit. The resonant frequency was decreased linearly as to layers of LB films, however, there are some gap between theoretical values, Sauerbrey's equation and experimental values. The resistance was increase nonlinearly as to layers.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2012년도 춘계 학술논문 발표대회
• /
• pp.275-278
• /
• 2012

This study try to finding the self-detergency performance of adherent pollutant on the mortar surface by using the developed silicate based antifouling coating material. Developed coating material coated on the surface of mortar test piece and after 30 minutes, over layed already coated mortar surface. After 7 days, the surface is polluted with crayons and oily magic marker. After 24 hours, contaminated area was wiped out the water. From the result of self-detergency performance test, it is concluded the developed material could be used as a detergent the contaminated concrete surface.

• Elastomers and Composites
• /
• 제2권1호
• /
• pp.31-36
• /
• 1967

As a series of the studies of thin rubber coated fabrics, the experiments were concentrated on the investigation of the physical properties of the surface and back coated fabrics with natural and synthetic rubber. Cotton poplin and nine other cotton shootings were used as a base fabric and both sides of fabric, face and back, were coated by means of topping or spreading process. The physical properties of finished material were broadly investigated especially in view of the quality requirements of the poncho.

• 한국기계기술학회지
• /
• 제13권3호
• /
• pp.31-37
• /
• 2011

The purpose of this study is to investigate cutting characteristics and wear behavior in SCM440 steel with different cutting tools, CBN(Cubic Boron Nitride) and coated CBN. During the test coated CBN tool especially with TiAlN showed better wear resistance behavior than orginal CBN tools. In the interrupted cutting condition, axial groove affected tool surface with impact force during the turning operation. For advantageous turning parameter in the interrupted process it is recommendable that lower speed. Also surface roughness showed better behavior in the coated CBN tool conditions than normal CBN conditions. Mainly this is caused by reduced friction between material and tool surface with coated layer.

• 한국전기전자재료학회논문지
• /
• 제36권6호
• /
• pp.638-646
• /
• 2023

Recently, active research has been conducted to enhance the power characteristics and thermal stability of lithium-ion batteries (LiBs) by modifying separators using a ceramic coating method. However, since the thermal properties and surface features of the separator vary depending on the characteristics of the ceramic powders applied to the separator, it is crucial to manufacture ceramic powders optimized for the separator's performance. In this study, we evaluated the characteristics of three types of α-alumina (A-1, A-2, and A-3) produced with varying dispersant contents and milling times, in addition to commercial α-alumina (AES-11). Subsequently, the optimized powders (A-3) were coated onto the separator using an aqueous binder for comparison with the characteristics of an AES-11 coated separator and an uncoated PE separator. The A-3 coated separator improved electrolyte wettability with a low contact angle (44.69°) and increased puncture strength (538 gf). Furthermore, it exhibited excellent thermal stability, with a shrinkage value of 5.64% when exposed to 140℃ for 1 hour, compared to the AES11 coated separator (6.09%) and the bare PE separator (69.64%).

• 한국물환경학회지
• /
• 제26권3호
• /
• pp.454-459
• /
• 2010

This study investigated the applicability of manganese coated media such as manganese coated sand (MCS), manganese coated sericite (MCSe) and manganese coated starfish material calcined at $550^{\circ}C$ (MCSf) to remove Mn(II) in synthetic wastewater. Manganese coated media prepared at different pH was applied in the treatment of soluble Mn(II) in batch and column experiments at various Mn(II) concentrations. The amount of Mn coated on three different media was approximately 800~1100 mg/kg. From the stability test, negligible dissolution of Mn was observed above pH 3.0. In batch test, more than 40% of Mn(II) was removed by all sand media at various manganese concentrations. In order to see the effect of additional oxidant for the removal of Mn(II), 4 mg/L of hypochlorite was added in Mn(II) solution during column experiment. Breakthrough of Mn(II) was greatly retarded in the presence of hypochlorite in all column reactors packed with different media. Among the manganese coated media, MCSf prepared at pH 4 indicated the highest removal capacity. The removal efficiency of Mn(II) was also increased in the multi-layer system (0.5 g of MCS, MCSe, and MCSf each).