• Title/Summary/Keyword: SEI growth

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Study of the Calendar Aging of Lithium-Ion Batteries Using SEI Growth Models (SEI 성장 모델을 이용한 리튬 이온 배터리의 캘린더 노화 연구)

  • Dong Hyup Jeon;Byungman Chae;Sangwoo Lee
    • Applied Chemistry for Engineering
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    • v.35 no.1
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    • pp.48-53
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    • 2024
  • We predicted the calendar aging and long-term lifetime of lithium-ion batteries using an electrochemical-based SEI growth model. Numerical simulation was carried out employing the four different long-term SEI growth models (i.e., solvent diffusion limited model, electron migration limited model, Li-interstitial diffusion limited model, reaction limited model), and we calculated the capacity fade and loss of lithium inventory during calendar aging. The result showed that the electron migration limited model and Li-interstitial diffusion limited model showed lower capacity fade, while the solvent diffusion limited model and reaction limited model reached 80% of capacity fade within 10 years. During calendar aging, the lower storage temperature showed less capacity fade due to the hindrance of SEI growth rate. During cycling, the higher C-rate showed a shorter life cycle; however, the differences were not significant.

CROUZON'S DISEASE: A Case Report (Crouzon's disease 의 증례)

  • Son, Heung-Kyu;Kim, Soon-Joo;Choi, Byung-Jai;Lee, Myoung-Sook
    • Journal of the korean academy of Pediatric Dentistry
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    • v.11 no.1
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    • pp.249-254
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    • 1984
  • This is a case report of Crouzon's disease as a kind of craniofacial dysostosis by premature closure of unilateral coronal suture, showed plagiocephalic skull. 5-year-old boy was visited for the treatment of dental caries and oral examination. Physical examination showed hypertelorism, internal strabismus, and saddle nose. Intraoral radiographs showed congenital missing of upper right and left deciduous and permanent lateral incisors. Cephalometric analysis showed shortening the posterior cranial base length, clockwise growth pattern and class III and open bite tendency. Posterior-anterior and submentovertex view showed multiple radiolucencies-digital impression on inner surface of cranial vault. Maxillo-facial and neuro-surgical treatment was required to improvement of facial esthetics and optic complications. Continuous examination was needed to the growth and development.

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A Study on the CdTe Single Crystal Growth by Vertical Bridgman Method (수직 Bridgman 법에 의한 CdTe 단결정 성장에 관한 연구)

  • Lee, Jong-Ki;Kim, Wook;Baik, Hong-Koo
    • Journal of Korea Foundry Society
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    • v.10 no.4
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    • pp.324-331
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    • 1990
  • The single crystal of CdTe was grown by modified 6 zone Bridgman method under the conditions of excess Te and excess Cd. To prevent the constitutional supercooling, the crystal growth was done under the temperature gradient of $17^{\circ}C/cm$ in front of the solid /liquid interface and the growth rate was 3mm/hr. The grain morphologies and the growth mechanism were investigated in excess Te and excess Cd conditions. The grain size of excess Te crystal was increased with an increase of the distance from the tip but, in the case of excess Cd crystal, single crystal was not obtained because of the cavities due to the excess Cd vapors so that the grain size was not increased with an increase of the distance from the tip. In addition, the growth of single crystal of CdTe was done with repeated necking ampoule. It was found that the necking had no effects on the grain selection because the cavities trapped in the necking portion acted as heterogeneous nucleation sites.

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Review on Effective Skills to Inhibit Dendrite Growth for Stable Lithium Metal Electrode (리튬금속전극의 덴드라이트 성장 억제 방안의 연구 동향)

  • Kim, Yerang;Park, Jihye;Hwang, Yujin;Jung, Cheolsoo
    • Journal of the Korean Electrochemical Society
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    • v.25 no.2
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    • pp.51-68
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    • 2022
  • Although lithium metal batteries have a high energy density, experimental skills capable of solving lots of problems induced by dendrite such as short circuit, low coulomb efficiency, capacity loss, and cycle performance are still only in academic research stage. In this paper, research cases for dendrite growth inhibition on lithium metal electrode were classified into four types: flexible SEI (solid electrolyte interface) layer responding to volume expansion of lithium metal electrode, SEI supporting layer to inhibit dendrite growth physically, SHES (self-healing electrostatic shield) mechanism to adjust lithium growth by leading uniform diffusion of Li+ ions, and finally micro-patterning to induce uniform deposition of lithium. We hope to advance the practical use of lithium metal electrode by analyzing pros and cons of this classification.

Novel estimation method of operating life in lithium-ion pouch cells

  • Kim, Hyosung;Kim, Jaekwang;Kim, Nayeong;Lee, Ilbok;Hwang, Keebum;Bae, Joongho;Yoon, Songhun
    • Journal of Industrial and Engineering Chemistry
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    • v.67
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    • pp.266-275
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    • 2018
  • Herein, a novel operating life (OL) test method was evaluated with 200 mAh pouch-type lithium-ion batteries. By combining the calendar life (CL) test with intermediate pulse power cycling, more realistic life prediction was possible, which encompassed real operation of batteries accompanying with thermal acceleration. Larger capacity decrease and resistance increase of pouch cell were observed in the OL test, which was well explained using the SEI film growth model. After dissemble of pouch cell, capacity loss and resistance increase mostly occurred within anode, reflecting that SEI film growth on anode surface was highly attributable to cell degradation.

A Longitudinal Study of The Soft Tissue Profile Changes in 6 to 11 Years Children (E국민학교생 6~11세 아동에 있어서 악안면 연조직의 성장변화에 관한 누년적 연구)

  • Park, Young-Chel;Son, Byung-Hwa
    • The Journal of the Korean dental association
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    • v.23 no.6 s.193
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    • pp.527-538
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    • 1985
  • The purpose of this study is to evaluate the chronologic changes of the soft tissue profile in 6 to 11 years children. The author analyzed 174 cephalometric roentgenograms of 13 boys and 16 girls taken from the ages of 6 to 11 to assess the growth changes of the soft tissue profile. The results were obtained as follow: 1. Means, standard deviation and coefficient of variation of children were obtained. 2. Items which showed difference between males and females in longitudinal study were prn. Sn. A', and Ls that were greater than females variation. 3. With age, thickness of the soft tissue were increased except Ls. 4. Nasolabial angle and facial convexity had no significant change with age and sex.

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Molecular Basis of Drug Resistance: Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors and Anaplastic Lymphoma Kinase Inhibitors

  • Yang, Sei-Hoon
    • Tuberculosis and Respiratory Diseases
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    • v.75 no.5
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    • pp.188-198
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    • 2013
  • Over the past decade, several kinase inhibitors have been approved based on their clinical benefit in cancer patients. Unfortunately, in many cases, patients develop resistance to these agents via secondary mutations and alternative mechanisms. To date, several major mechanisms of acquired resistance, such as secondary mutation of the epidermal growth factor receptor (EGFR) gene, amplification of the MET gene and overexpression of hepatocyte growth factor, have been reported. This review describes the recent findings on the mechanisms of primary and acquired resistance to EGFR tyrosine kinase inhibitors and acquired resistance to anaplastic lymphoma kinase inhibitors, primarily focusing on non-small cell lung carcinoma.

Effects of Ridge Height in Dry Paddy Field on Growth and Seed Yield of Soybean Cultivars

  • Seong, Rak-Chun;Park, Sei-Joon;Shim, Sang-In
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.45 no.2
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    • pp.88-92
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    • 2000
  • Excessive soil water in paddy field induces growth losses during the vegetative stages of soybean plants. Our objectives were to know growth responses of soybean as affected by the level of ridge heights. A field experiment was conducted at the Research Farm of Korea University near Seoul in 1996. Ten cultivars of soybean (Glycine max (L.) Merrill) were planted at the ridge heights of 10, 30, and 50cm in paddy soil on 27 June. Total dry matter accumulation at the 10cm ridge height was severely decreased until the growth stage of R5 as compared to the ridge heights of 30 and 50cm, and this decrement was mainly due to both reduced leaf and stem dry weights. However, seed dry weight was not significantly decreased at the lower ridge height with the increment of harvest index. Cultivar differences were found on seed dry weight, crop growth rate from R1 to R5, and leaf/stem ratio of R5. From the above results, soybean growth responses to excessive soil water in paddy field were different between seed filling stage and late vegetative to early reproductive growth stages.

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