• 한국표면공학회지
• /
• 제57권4호
• /
• pp.317-324
• /
• 2024

We demonstrate a direct growth of carbon nanotubes (CNTs) on the surface of LiFePO₄ (LFP) powders for use in lithium-ion batteries (LIB). LFP has been widely used as a cathode material due to its low cost and high stability. However, there is a still enough room for development to overcome its low energy density and electrical conductivity. In this study, we fabricated novel structured composites of LFP and CNTs (LFP-CNTs) and characterized the electrochemical properties of LIB. The composites were prepared by direct growth of CNTs on the surface of LFP using a rotary chemical vapor deposition. The growth temperature and rotation speed of the chamber were optimized at 600 ℃ and 5 rpm, respectively. For the LIB cell fabrication, a half-cell was fabricated using polytetrafluoroethylene (PTFE) and carbon black as binder and conductive additives, respectively. The electrochemical properties of LIBs using commercial carbon-coated LFP (LFP/C), LFP with CNTs grown for 10 (LFP/CNTs-10m) and 30 min(LFP/CNTs-30m) are comparatively investigated. For example, after the formation cycle, we obtained 149.3, 160.1, and 175.0 mAh/g for LFP/C, LFP/CNTs-10m, and LFP/CNTs-30m, respectively. In addition, the improved rate performance and 111.9 mAh/g capacity at 2C rate were achieved from the LFP/CNTs-30m sample compared to the LFP/CNTs-10m and LFP/C samples. We believe that the approach using direct growth of CNTs on LFP particles provides straightforward solution to improve the conductivity in the LFP-based electrode by constructing conduction pathways.

• 한국식품조리과학회지
• /
• 제26권5호
• /
• pp.586-595
• /
• 2010

This study was conducted to examine the quality characteristics of tofu prepared with Lycii fructus powder(LFP) during storage for 15 days at $5{\pm}1^{\circ}C$. The moisture content, yield rate, tofu whey content and turbidity of soaking solutions of tofu prepared with LFP increased upon the addition of LFP. The pH of tofu prepared with LFP decreased while the acidity increased lightly; however, the acidity of the tofu did not differ significantly according to the level of added LFP. The L value of tofu decreased as the amount of LFP in the formulation increased, whereas the a and b values increased. The color value of tofu prepared with LFP did not depend upon the storage period. The hardness increased significantly with the level of LFP, but it did not differ significantly according to the storage period. The microbial count of tofu prepared with LFP was lower than that of control tofu during the storage period. In terms of overall preference, the preferred tofu contained 1.0% LFP tofu.

• 한국식생활문화학회지
• /
• 제28권5호
• /
• pp.495-501
• /
• 2013

The quality characteristics of tofu added Ligularia fischeri powder (LFP) were investigated. The proximate composition of LFP used was as follows: moisture, 7.7%; crude protein, 12.0%; crude lipid, 5.9%; crude ash, 14.1%; and carbohydrate, 60.3%. The yield of tofu added LFP increased with the addition of LFP. However, there was a significant decrease in pH (from $6.03{\pm}0.11$ in the control to $5.78{\pm}0.11$ when 0.4% LFP was added) and a significant increase (from $2.60{\pm}0.01$ in the control to $2.85{\pm}0.10$ when 0.4% LFP was added) in total acidity. In addition, the L, a, and b values of tofu decreased with the increasing addition of LFP. In terms of textural properties, the hardness, cohesiveness, and brittleness increased, whereas springiness decreased, with the increasing addition of LFP. In the sensory evaluation, the overall preference for tofu added 0.3% LFP was the highest. According to the results, the addition of LFP positively affects the overall sensory evaluation of tofu, and 0.3% is the optimal level for addition.

• 한국식품조리과학회지
• /
• 제21권1호
• /
• pp.94-102
• /
• 2005

The purpose of this study was to investigate the antioxidative effect and quality characteristics of cookies made with Lycii fructus powder(LFP). The cookies were stored at $50^{\circ}C$ for 40 days. The LFP additive increased the moisture, ash, crude protein and volume of the cookies. When LFP was added at $5\%$ into the cookies, the spread ratio was higher than for the control, the $10\%$ and the $20\%$ LFP cookies. As more LFP was added, the L-value decreased, and the a--values and b-values increased for the color values. For the textural characteristics, springiness and cohesiveness of the control cookies were the highest among the samples, the other side, brittleness and gumminess were higher in cookies made with LFP than in the control cookies. Overall, the cookies made with $5\%$ LFP were preferred more than the other cookies, as tested forby sensory evaluation. The cookies made with LFP contained mostly palmitic acid (C16:0) followed by oleic acid (C18: 1) and stearic acid (C18:0). The acid value, peroxide value, and thiobarbituric acid value were lower in cookies made with $5\%$ and $10\%$ LFP than in those cookies made with $20\%$ LFP and the control cookies.

• 한국식품조리과학회지
• /
• 제31권2호
• /
• pp.144-152
• /
• 2015

The loquat (Eriobotrya japonica) is a plant belonging to the Rosaceae family, native to south-central China. It is cultivated in relatively warm areas such as Spain, Japan and South Korea. It is used commercially as an ornamental plant and for its yellow fruit, which contains much carotenoid, sugar and a little organic acid. In this study, chiffon cakes were prepared with the addition of 3%, 6%, 9% and 12% loquat fruit powder (LFP) in order to invest the mixing conditions. When more LFP was added to the dough, the pH level of the dough became lower. Specific gravity and viscosity of the dough significantly increased as higher amounts of LFP were added. In baked cakes, the weight and baking loss rate of LFP were not significantly different between samples, and the height of the risen test samples were lower than that of the controls. Moisture content was 33.58% in the 12% LFP sample (12% LFPS), which was the highest of all the samples. With respect to crust color, lightness, redness and, yellowness, these significantly decreased as the amount of LFP was increased, the 12% LFP being the lowest of all the samples. Lightness and yellowness of crumbs significantly decreased as the amount of LFP was increased, whereas redness showed the reverse effect. When looking at hardness and adhesiveness, the 12% LFPS was the highest of all the samples, nevertheless a difference in resilience was not significant among the samples. According to consumer perception, bitterness was significantly increased as amounts of LFP increased, however a difference in salty, astringency and oily tastes were not significant among the samples. The 12% LFPS showed the lowest score with respect to softness and overall acceptability. In conclusion, LFP could be considered a functional material, with the optimum amount of LFP for a chiffon cake of 3~9%.

• 한국지열·수열에너지학회논문집
• /
• 제18권4호
• /
• pp.1-11
• /
• 2022

In this study, the thermal runaway of NCM and LFP batteries were compared and analyzed through numerical analysis under various conditions. Comparing the thermal runaway of the NCM622 (18650) battery cell and the LFP (18650) battery cell through oven test simulation, the LFP battery did not show thermal runaway, whereas the NCM622 battery temperature increased to 710℃ in 12 minutes. To observe the thermal runaway and propagation of the prismatic LFP battery cell, the internal temperature was set at 200℃ and the oven test simulation was conducted. It was found that thermal runaway occurred at 391℃ after 47 minutes. As a result of observing thermal runaway propagation by placing five NCM622 and LFP battery cells, the thermal runaway propagation was clearly observed in the case of the NCM622 battery, but in the case of the LFP battery, thermal runaway was not observed after the first cell. From the third battery cell, it was confirmed that the temperature change was very insignificant, and through this, it is considered that the LFP battery is relatively safe compared to the NCM battery in terms of the thermal runaway propagation of the battery.

• 한국식생활문화학회지
• /
• 제23권4호
• /
• pp.521-528
• /
• 2008

This study examined the effects of 2% Lycii fructus powder (LFP) supplementation on lipid metabolism in rats. Male Sprague-Dawley rats were administered 1% cholesterol and 0.25% sodium cholate to induce hypercholesterolemia. Then, 40 rats were divided into four diet groups: a normal diet group (NC), high cholesterol diet group (HC), normal diet plus 2% Lycii fructus powder (NC-LFP) group, and high cholesterol diet plus 2% Lycii fructus powder (HC-LFP) group. The HC group presented higher growth rates and liver weights than NC and NC-LFP however, growth rates and liver weights in the 2% LFP administered groups gradually decreased. HC also showed increased serum triglyceride, total cholesterol, free cholesterol, and LDL-cholesterol levels and decreased atherogenic index values, HDL-cholesterol, and phospholipid levels, whereas LFP group showed decreased serum triglyceride, total cholesterol, free cholesterol, and LDL-cholesterol levels as compared to HC. There were no differences in serum triglyceride, phospholipid, LDL-cholesterol, HDL-cholesterol, and free cholesterol concentrations between the normal diet groups (NC and NC-LFP). The high cholesterol diet groups (HC and HC-LFP) had significant increases in serum alanine aminotransferase (ALT), asparate aminotransferase (AST), alkaline phosphatase (ALP), and lactate dehydrogenase (LDHase) activities. And the 2% LFP administered groups had lower hepatic concentrations of total cholesterol and triglycerides than the HC groups. Overall, the results suggest that Lycii fructus powder has hypochloesterolemic effects by reducing serum and liver cholesterol contents.

• Journal of Electrochemical Science and Technology
• /
• 제9권2호
• /
• pp.85-92
• /
• 2018

Olivine structure of $LiFePO_4$ (LFP) is one of the most commonly used materials in aqueous rechargeable lithium batteries (ARLBs), and can store and release charge through the insertion/de-insertion of $Li^+$ between LFP and FP. We have fabricated LFP and LFP/FP electrodes on titanium paper and studied their electrochemical properties in 2 M $Li_2SO_4$. The LFP/FP electrode was determined to be a suitable electrode for electo-ostmotic pump (EOP) in terms of efficiency in water and 0.5 mM $Li_2SO_4$ solution. Experiments to determine the effect of cations and anions on the performance of EOP using LFP/FP electrode have shown that $Li^+$ is the best cation and that the anion does not significantly affect the performance of the EOP. As the concentration of $Li_2SO_4$ solution was increased, the current increased. The flow rate peaked at $4.8{\mu}L/30s$ in 1.0 mM $Li_2SO_4$ solution and then decreased. When the EOP was tested continuously in 1.0 mM $Li_2SO_4$ solution, the EOP transported approximately 35 mL of fluid while maintaining a stable flow rate and current for 144 h.

• 한국식생활문화학회지
• /
• 제29권2호
• /
• pp.205-211
• /
• 2014

This study investigated the quality of noodles containing different amounts of Ligularia fischeri powder (LFP). Noodles were prepared at ratios of 0, 1, 3, 5, and 7% LFP based on flour weight. Cooking quality, mechanical texture properties, and viscosity were measured, and a sensory evaluation was performed with the prepared noodles. Gelatinization points of the composite LFP-wheat flours increased. As measured via amylography, viscosity at $95^{\circ}C$, viscosity at $95^{\circ}C$ after 15 minutes, and maximum viscosity values of samples decreased, as the LFP content increased. As increasing amounts of LFP were added, the L, a, and b values decreased while color values, weight, and volume of cooked noodles increased, as did the turbidity of the soup. With regard to textural characteristics, LFP additive increased hardness, cohesiveness, and springiness, while decreasing adhesiveness. Sensory evaluation showed that high quality cooked noodles could be produced by inclusion of 3% LFP.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
• /
• pp.126.1-126.1
• /
• 2015

A quantitative relationship between Leidenfrost point and surface characteristics such as surface material and roughness is investigated. Based on the relationship, we have fabricated the surfaces with their Leidenfrost points (LFP) tuned by controlling surface coating and structures. As discovered by Leidenfrost, liquids placed on a hot plate levitate on the gas phase-air gap formed by the vaporization of liquids. This phenomenon is called 'Leidenfrost effect'. A change of LFP has attracted many researchers for several years but the ability to tune LFP is still a remaining issue. Many of previous work has progressed for various conditions so the systematic approach and analysis are needed to clearly correlate the LFP and the surface conditions. In this report, we investigate a relation of surface energy and LFP using various coating materials such as Octadecyltrichlorosilane (OTS) and 1H, 1H, 2H, 2H-Perfluorooctyltrichlorosilane (FOTS). Also, we analyze how surface roughness affects LFP via surface micro structuring with ICP-RIE fabrication process. The improved understanding can have potential applications such as the control of liquid droplet behavior at elevated temperatures for efficient cooling system.