http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Effect of nanoparticles in cathode materials for flexible Li-ion batteries
Kookjin Heo,Jehong Im,Seokhun Kim,Chang-Kee Lee,Duck-Rye Chang,Jaekook Kim,Jong-Won Lee,임진섭 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.81 No.-
In this article, we report the effect of using nanoparticles for LiMn2O4 cathode materials inflexiblebatteries with organic–inorganic hybrid electrolytes. LiMn2O4 nanoparticles for the cathode are preparedby pyro-synthesis. Electrochemical measurement indicated the discharge capacities were 118.41 and138.12 mA h g 1 and the coulombic efficiencies were 91.50% and 97.28% for the micro- and nano-LMOmaterials, respectively. This is attributed to the nano-LiMn2O4 material having particle sizes in thenanoscale dimension, and shorter diffusion paths combined with a large contact area at the electrode/electrolyte interface. Furthermore, the pouch-type cells demonstrated similar properties, with initialdischarge capacities of 85.63 and 99.96 mA h g 1 and coulomb efficiencies of 79.27% and 90.27% for themicro- and nano-LMO cells, respectively. Nanoparticles allow Li+ ions to de-intercalate and intercalatevery easily because of the very short lithium diffusion distance.
부식환경하에서 쇼트피닝 가공에 의한 Al 7075-T6의 피로특성
이국진(Kookjin Lee),이동선(Dongsun Lee),정성균(Seongkun Cheong) 한국자동차공학회 2005 한국자동차공학회 춘 추계 학술대회 논문집 Vol.2005 No.11_3
Corrosion fatigue life of a metal is greatly affected by the surface state of the metal. The shot peening process is know to have excellent effects on the fatigue life of parts by increasing the parts' resistance to corrosion. In this paper, the improvement of durability of shot peened Al 7075- T6 is studied under corrosive environment. Specimens were submerged in 3.5% NaCl from one week to two years before fatigue testing. It is attempted to estimate the peening layer in shot peened Al 7075 by ultrasonic velocity, such as leaky surface acoustic wave(LSAW). The fractured surface is examined by scanning electron microscope (SEM). The experimental results show that the corrosion fatigue resistance of Al 7075-T6 is greatly improved by shot peening process.
Heo, Kookjin,Lee, Jeong-Seon,Kim, Ho-Sung,Kim, Min-Young,Jeong, Hyejeong,Kim, Jaekook,Lim, Jinsub The Electrochemical Society 2018 Journal of the Electrochemical Society Vol.165 No.13
<P>The advantage of the co-precipitation method is that the precursors react uniformly at the molecular level. Both Ni-rich cathode materials and garnet-type lithium-ion conductor materials have typically been synthesized by the co-precipitation method. In this paper, we report on a composite of lithium-ion conductive and Ni-rich cathode materials with improved electrochemical properties, synthesized by simultaneous co-precipitation. This process is a very simple and useful method for preparing the composite due to uniform precipitation from the precursor phase. The physical, chemical, and electrochemical characteristics of the ionic conductor Ni-rich cathode composite material were investigated. (C) 2018 The Electrochemical Society.</P>
Heo, Kookjin,Lee, Jeong-Seon,Kim, Ho-Sung,Kim, Jaekook,Lim, Jinsub The Electrochemical Society 2017 Journal of the Electrochemical Society Vol.164 No.12
<P>A Li6.75La3Zr2Al0.25O12 (LLZAO)-coated LiNi0.7Co0.15Mn0.15O2 (LNCM) cathode is synthesized using a simple one-step calcination process. LLZAO is a fast ionic conductor that could effectively enhance the lithium-ion diffusion at the electrode/electrolyte interface. The LLZAO-coated LNCM exhibits relatively better electrochemical performance than pristine LNCM, with a superior initial discharge capacity of 191 mAh g(-1) and good rate capability at a high rate of 5C. Furthermore, electrochemical impedance spectroscopy measurement indicates that the interfacial resistance of the LLZAO-coated sample is lower than that of pristine LNCM, which strongly indicates that coating LNCM in LLZAO improves the lithium-ion transport at the electrode/electrolyte interface. (C) The Author(s) 2017. Published by ECS. All rights reserved.</P>
안국진(Kookjin Ann),민형기(Hyeong Ki Min),한규홍(Kyuhong Han) 한국자동차공학회 2019 한국자동차공학회 학술대회 및 전시회 Vol.2019 No.11
This paper presents a modeling and performance analysis for braking system of 6 wheel vehicle. The braking system of 6 wheel vehicle is consisted of hydraulic brake and electronic parking brake. The electronic parking brake can be used when the hydraulic brake system is failed. To predict the braking performance, the vehicle and braking system was modeled via TruckSim/Matlab software. Based on the vehicle model, braking simulation is conducted in various scenarios. The performance of the braking system was analyzed by the simulation using the implemented vehicle model.
High-Rate Blended Cathode with Mixed Morphology for All-Solid-State Li-ion Batteries
Heo, Kookjin,Im, Jehong,Lee, Jeong-Seon,Jo, Jeonggeon,Kim, Seokhun,Kim, Jaekook,Lim, Jinsub The Korean Electrochemical Society 2020 Journal of electrochemical science and technology Vol.11 No.3
In this article, we report the effect of blended cathode materials on the performance of all-solid-state lithium-ion batteries (ASLBs) with oxide-based organic/inorganic hybrid electrolytes. LiFePO<sub>4</sub> material is good candidates as cathode material in PEO-based solid electrolytes because of their low operating potential of 3.4 V; however, LiFePO<sub>4</sub> suffers from low electric conductivity and low Li ion diffusion rate across the LiFePO<sub>4</sub>/FePO<sub>4</sub> interface. Particularly, monoclinic Li<sub>3</sub>V<sub>2</sub>(PO<sub>4</sub>)<sub>3</sub> (LVP) is a well-known high-power-density cathode material due to its rapid ionic diffusion properties. Therefore, the structure, cycling stability, and rate performance of the blended LiFePO<sub>4</sub>/Li<sub>3</sub>V<sub>2</sub>(PO<sub>4</sub>)<sub>3</sub> cathode material in ASLBs with oxidebased inorganic/organic-hybrid electrolytes are investigated by using powder X-ray diffraction analysis, field-emission scanning electron microscopy, Brunauer-Emmett-Teller sorption experiments, electrochemical impedance spectroscopy, and galvanostatic measurements.