• Journal of the Korean Electrochemical Society
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• v.3 no.3
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• pp.152-156
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• 2000

The effect of cupric ion concentration on the throwing power has been studied in the electrodeposition of Cu on the porous reticular electrodes with the electrolytes of $CuSO_4\;and\;H_2SO_4$. Sulfuric acid electrolytes with lower concentration of $CuSO_4$ improved throwing power in electrodeposition of copper not only due to higher cathodic polarizability but also due to higher conductivity of the electrolytes. The increase in conductivity of the electrolytes at low concentration of $CuSO_4$ could be also illustrated by the decrease in viscosity of the electrolytes. It was found that both the throwing power and the limiting current density should be taken into account in the electrodeposition of Cu on the reticular electrodes. According to the experimental results, the electrolyte of 0.2M $CuSO_4$ and 0.5M $H_2SO_4$ was found to be the most appropriate condition at the current density of $10mA/cm^2$.

• Applied Chemistry for Engineering
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• v.32 no.4
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• pp.467-471
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• 2021

A ladder-like polysilsesquioxane (LPMA64) functionalized with a crosslinkable group was synthesized and used for the preparation of organic-inorganic hybrid gel polymer electrolytes through a thermal crosslinking process of the liquid electrolytes. A small weight percent of LPMA64 polymer crosslinker (5 wt%) was able to form a well-developed network structure, resulting in good dimensional stability with high ionic conductivity. The lithium-sulfur batteries fabricated with organic-inorganic hybrid gel polymer electrolytes exhibited stable C-rate and cycling performance with excellent Coulombic efficiency due to the alleviated lithium polysulfide shuttling effect during prolonged cycling. The result demonstrates that the organic-inorganic hybrid gel polymer electrolytes could be a promising candidate electrolyte for application in lithium-sulfur batteries.

• Korean Journal of Materials Research
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• v.31 no.11
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• pp.614-618
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• 2021

As the size of market for electric vehicles and energy storage systems grows, the demand for lithium-ion batteries (LIBs) is increasing. Currently, commercial LIBs are fabricated with liquid electrolytes, which have some safety issues such as low chemical stability, which can cause ignition of fire. As a substitute for liquid electrolytes, solid electrolytes are now being extensively studied. However, solid electrolytes have disadvantages of low ionic conductivity and high resistance at interface between electrode and electrolyte. In this study, Li₇La₃Zr₂O₁₂ (LLZO), one of the best ion conducting materials among oxide based solid electrolytes, is fabricated through RF-sputtering and various electrochemical properties are analyzed. Moreover, the electrochemical properties of LLZO are found to significantly improve with co-sputtered Li₂O. An all-solid thin film battery is fabricated by introducing a thin film solid electrolyte and an Li₄Ti₅O₁₂ (LTO) cathode; resulting electrochemical properties are also analyzed. The LLZO/Li₂O (60W) sample shows a very good performance in ionic conductivity of 7.3×10^-8 S/cm, with improvement in c-rate and stable cycle performance.

• Journal of the Korean Electrochemical Society
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• v.25 no.1
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• pp.22-31
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• 2022

Carbon nanomaterials are considered to be the materials of choice for the fabrication of electrochemical energy storage devices due to their stability, cost-effectiveness, well-established processing techniques, and superior performance compared to other active materials. In the present work, reduced graphene oxide (rGO) has been synthesized and used for the fabrication of a symmetric supercapacitor. The electrochemical performance of the fabricated supercapacitors with three different aqueous electrolytes namely 0.5 M H₂SO₄, 0.5 M H₃PO₄, and 1.0M Na₂SO₄ have been compared and analyzed. Among the three electrolytes, the highest areal specific capacitance of 14 mF/cm² was calculated at a scan rate of 5 mV/s observed with 0.5M H₃PO₄ electrolyte. The results were also confirmed from the charge/discharge results where the supercapacitor with 0.5M H₃PO₄ electrolyte delivered a specific capacitance of 11 mF/cm² at a current density of 0.16 mA/cm². In order to assess the stability of the supercapacitor with different electrolytes, the cells were subjected to continuous charge/discharge cycling and it was observed that acidic electrolytes showed excellent cyclic stability with no appreciable drop in specific capacitance as compared to the neutral electrolyte.

• Clinical and Experimental Pediatrics
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• v.46 no.11
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• pp.1089-1094
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• 2003

Purpose : Polyethylene glycol(PEG) with electrolytes has been used for intestinal clearance for colonoscopy and operations in children. But its efficacy and safety for disimpaction in children with chronic functional constipation has been studied little. Methods : This study enrolled 26 patients with chronic functional constipation(11 children had failed to disimpaction by conventional management at OPD) who were admitted to the Eul-Ji Hospital between May 2000 and July 2003. PEG with electrolytes was administered per oral and/or rectal enema. We observed the effects for disimpaction by measuring the frequency and consistency of stools, and by simple abdominal X-ray. We evaluated the safety by measuring serum electrolytes and osmolarity in three hours after PEG with electrolytes administration, and by observation of the clinical status of the patients. The protocol of PEG with electrolytes was a dose of 60-80 mL/kg within three hours per oral and/or of 15-25 mL/kg by rectal enema. Results : In all patients, simple abdominal X-ray films showed improvements of fecal impaction. Consistency and frequency of stool were improved in all patients except one. As for side effects, diarrhea developed in three patients(11.5% of all patients). Headaches developed in one patient(3.8% of all patients) but it improved without treatment. Serum electrolytes was checked in 16 patients after PEG with electrolytes management and mild hypernatremia(146 mmol/L) was checked in one patient. Serum osmolarity was checked in 11 patients after PEG with electrolytes management and was normal in all patients. Conclusion : PEG with electrolytes was effective and safe for disimpaction in children with chronic functional constipation, including patients who had failed in disimpaction by conventional management.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.9
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• pp.756-760
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• 2007

Flame retardant(FR) properties were investigated with tricredyl phosphate(TCP) and tris(pentafluorophenyl)phosphine(TFPP) as additives for lithium-ion batteries. Thermal stability was improved with additives in $Li/LiNi\frac{1}{3}Mn\frac{1}{3}Co\frac{1}{3}O_2$ cells comparing to non-additive electrolytes. Oxygen evolution reaction of the cathode material was delayed to up $55^{\circ}C$, from $275^{\circ}C\;to\;330^{\circ}C$. Electrolytes with the 1 wt.% additives provided good FR properties while the resonable battery performance is maintained.

• Korean Journal of Materials Research
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• v.18 no.9
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• pp.470-474
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• 2008

Composites of gadolinium-doped ceria/magnesia(CGO/MgO) were synthesized and characterized for the electrolytes of intermediate temperature solid oxide fuel cells. XRD and SEM results revealed that composite electrolytes consisted of their own phases after sintering at $1400^{\circ}C$ without noticeable solid solution of Mg into CGO. As the MgO content increased, the total electrical conductivity decreased, which might be attributed to the decrease of grain boundary conductivity, possibly due to the lowering of the continuity of the CGO grains and blocking effects of the insulating MgO phase. The space charge effect may not be a significant factor to affect the electrical conductivity of the CGO/MgO composites.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.275-275
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• 2006

A series of organoboron polymer electrolytes were prepared and their ion conductive characteristics was investigated in detail. Alkylborane type polymer electrolytes prepared by hydroboration polymerization exhibited improve lithium transference number due to efficient anion trapping of alkylborane unit. A lithium borate type polymer/salt hybrid was also successfully prepared by dehydrocoupling polymerization of lithium mesitylhydrorate. Ionic conductivity of single ion conductive polymer/salt hybrid was further improved in the case of comb like polymer/boron stabilized imido anion hybrid prepared via polymer reaction of poly(organoboron halide) with hexylamine and PEO monomethylether and subsequent neutralization with lithium hydride.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.273-273
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• 2006

The encapsulation of volatile organic electrolytes is a major challenge in practical applications of the DSSC. Ionic liquid (IL) within polymer electrolytes is an attractive candidate for replacement. Here we used a low viscosity ionic liquid 1-ethyl 3-methylimidazolium thiocyanate in order to modify ionic conductivity (${\sigma}$) of polymer electrolyte ($PEO:Kl/l_{2}$) and hence DSSC efficiency. The doping of IL enhanced ${\sigma}$ and attained maximum (${\sigma}=7.62{\times}10^{-4}S/cm$) at 80 wt% of IL concentration. Beyond this it was harder to get stable films. XRD confirmed that the intensity of the sharp PEO crystalline peaks decreased when IL was added. The DSC studies confirmed the reduction in crystallinity by adding ionic liquid.The efficiency of solar cell using aforesaid material was 0.6 % at 1 sun irradiation.

• Journal of Veterinary Clinics
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• v.16 no.2
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• pp.239-247
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• 1999

We estimated the changes of ECG and electrolytes in serum after intravenous administration of Succinylcholine Chloride (SCC), 0.15 mg/kg in ten normal mongrel dogs (mean 13 kg). Hyperkalemia was observed in the highest level by 6.46$\pm$0.8 mEq/L at ten minutes after the administration of SCC. The ECG appeared temporary the most severe changes as the increased T wave, the disappeared P wave, the prolonged of conduction times (PR, QTc intervals and QRS complex), and arrhythmia as ventricular premature contraction at 3 and 5 minutes after the administration SCC. Therefore, the changes of ECG after administration of SCC were suggested to specific and independent from hyperkalemic changes. Because these changes were observed to differ from ECG by hyperkalemia, and the highest period of $K^＋$value in serum differ from the appearance period of severe changes of ECG and arrhythmia by SCC.