http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
리튬이차전지용 부극재료로서 은분말에 대한 전기화학적 특성
박철완,도칠훈,문성인,윤문수 한국공업화학회 2003 응용화학 Vol.7 No.2
Silver powders have been extensively studied as an anode active material for lithium secondary batteries. In the present study, a unique attempt is made to develop silver negative electrode by slurry method, because the silver electrode is a good candidate to replace the commercial graphite electrode for lithium rechargeable batteries. Silver electrode was prepared and its electrochemical properties were characterized gradual increasing test state of charge (GISOC) analysis method. Charge-discharge performance indicates that the initial charge potential range of Li/Ag cells has showed similar behaviors compared with Li/Graphite system and the irreversible capacity facd is also higher than Li/Graphite system.
Cathode materials of Li ion battery
심영재,문성인,형유업,도칠훈,윤문수 국립경상대학교 공과대학 부설 첨단소재연구소 1994 尖端素材 Vol.4 No.-
Li ion 2차전지는 높은 전지전압, 낮은 자기방전율, High Energy Density High Power Density Non-Toxic, No Memory Effect등의 우수한 특성을 보유하고 있고, 환경적인 측면에서 Lead Acid 전지 및 Ni/Cd 전지 등과 같은 Pb, Cd 및 Hg 등으로 인한 환경오염문제가 없는 고성능 신형전지로써, 92년에 SONY사에서 최초의 시제품을 내놓은 이래 현재 소형녹음기, 캠코더 및 셀룰라폰용으로 시판되고 있으나 세계적으로 Li ion 전지를 생산할 수 있는 회사는 일본의 몇몇 기업으로 한정되어 있는 실정이다.
Doh, Chil-Hoon,Ha, Yoon-Cheol,Eom, Seung-wook Pergamon Press 2019 Electrochimica Acta Vol. No.
<P><B>Abstract</B></P> <P>As large format lithium ion batteries are used in EV and ESS applications, the temperature control of a battery is important to achieve a safe and long cycle life operation. To control the temperature properly, we need to know the heat generation characteristics. Heat generation of a battery mainly depends on the applied current, internal resistance, temperature and entropy of the battery. However, it is not easy to measure the entropy, because they depend on SOC and temperature simultaneously. Here, we suggested a new way to measure the entropy, on the assumption of adiabatic condition and calculate the heat generation. Internal resistance, specific heat capacity, OCCP values are also measured experimentally. The entropy (F ∂E<SUB>OC</SUB> ∂T<SUP>−1</SUP>) at a given SOC were measured from the variation of OCCP with temperature and expressed via a polynomial equation. The temperature dependence of the internal resistance were also expressed in the same procedure. The battery temperature variations calculated from the above parameters showed a good agreement with those from experiments. This suggested method provides a simple and reliable temperature estimation of lithium ion batteries.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
Doh, Chil-Hoon,Ha, Yoon-Cheol,Eom, Seung-Wook,Yu, Jihyun,Choe, Seon-Hwa,Kim, Seog-Whan,Choi, Jae-Won The Korean Electrochemical Society 2022 Journal of electrochemical science and technology Vol.13 No.3
Heat generation and temperature of a battery is usually presented by an equation of current. This means that we need to adopt time domain calculation to obtain thermal characteristics of the battery. To avoid the complicated calculations using time domain, 'state of charge (SOC)' can be used as an independent variable. A SOC based calculation method is elucidated through the comparison between the calculated results and experimental results together. Experiments are carried for rapid resistive discharge of a large-capacitive lithium secondary battery to evaluate variations of cell potential, current and temperature. Calculations are performed based on open-circuit cell potential (SOC,T), internal resistance (SOC,T) and entropy (SOC) with specific heat capacity.
Doh, Chil-Hoon,Kim, Dong-Hun,Lee, Jung-Hun,Lee, Duck-Jun,Jin, Bong-Soo,Kim, Hyun-Soo,Moon, Seong-In,Hwang, Young-Gi,Veluchamy, Angathevar Korean Chemical Society 2009 Bulletin of the Korean Chemical Society Vol.30 No.4
Thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and ion chromatography(IC) were employed to analyze the thermal behavior of $Li_xCoO_2$ cathode material of lithium ion battery. The mass loss peaks appearing between 60 and 125 ${^{\circ}C}$ in TGA and the exothermic peaks with 4.9 and 7.0 J/g in DSC around 75 and 85 ${^{\circ}C}$ for the $Li_xCoO_2$ cathodes of 4.20 and 4.35 V cells are explained based on disruption of solid electrolyte interphase (SEI) film. Low temperature induced HF formation through weak interaction between organic electrolyte and LiF is supposed to cause carbonate film disruption reaction, $Li_2CO_3\;+\;2HF{\rightarrow}\;2LiF\;+\;CO_2\;+\;H_2O$. The different spectral DSC/TGA pattern for the cathode of 4.5 V cell has also been explained. Presence of ionic carbonate in the cathode has been identified by ion chromatography and LiF reported by early researchers has been used for explaining the film SEI disruption process. The absence of mass loss peak for the cathode washed with dimethyl carbonate (DMC) implies ionic nature of the film. The thermal behavior above 150 ${^{\circ}C}$ has also been analyzed and presented.
Electrochemical study of nanometric Si on carbon for lithium ion secondary batteries
Doh, Chil-Hoon,Lee, Jung-Hoon,Lee, Duck-Jun,Kim, Ju-Seok,Jin, Bong-Soo,Moon, Seong-In,Hwang, Young-Ki,Park, Cheol-Wan Royal Swedish Academy of Sciences 2010 Physica scripta Vol.2010 No.t139
<P>The electrochemical and thermochemical properties of a silicon–graphite composite anode for lithium ion batteries were evaluated. The electrochemical properties were varied by the condition of pretreatment. The electrochemical pretreatment of constant current (C/10) and constant potential for 24 h showed specific discharge and charge capacities of 941 and 781 mA h g<SUP>−1</SUP> to give a specific irreversible capacity of 161 mA h g<SUP>−1</SUP> and a coulombic efficiency of 83%. The initial cycle as the next cycle of pretreatment showed a specific charge capacity (Li desertion) of 698 mA h g<SUP>−1</SUP> and a coulombic efficiency of 95%. Coulombic efficiency at the fifth cycle was 97% to clear up almost all of the irreversible capacity. During the pretreatment cycle to the fourth cycle, the average specific charge capacity was 683 mA h g<SUP>−1</SUP> and the cumulative irreversible capacity was 264 mA h g<SUP>−1</SUP>. Exothermic heat values based on the specific capacity of the discharged (Li insertion) electrode of silicon–graphite composite for the temperature range of 50–300 °C were 2.09 and 2.21 J mA<SUP>−1</SUP>h<SUP>−1</SUP> for 0 and 2 h as time of pretreatment in the case of just disassembled wet electrodes and 1.43 and 1.01 J mA<SUP>−1</SUP>h<SUP>−1</SUP> for 12 and 24 h as time of pretreatment in the case of dried electrodes, respectively.</P>
Effect of Silicon Content over Fe-Cu-Si/C Based Composite Anode for Lithium Ion Battery
Doh, Chil-Hoon,Shin, Hye-Min,Kim, Dong-Hun,Chung, Young-Dong,Moon, Seong-In,Jin, Bong-Soo,Kim, Hyun-Soo,Kim, Ki-Won,Oh, Dae-Hee,Veluchamy, Angathevar Korean Chemical Society 2008 Bulletin of the Korean Chemical Society Vol.29 No.2
Two different anode composite materials comprising of Fe, Cu and Si prepared using high energy ball milling (HEBM) were explored for their capacity and cycling behaviors. Prepared powder composites in the ratio Cu:Fe:Si = 1:1:2.5 and 1:1:3.5 were characterized through X-Ray diffraction (XRD) and scanning electron microscope (SEM). Nevertheless, the XRD shows absence of any new alloy/compound formation upon ball milling, the elements present in Cu(1)Fe(1)Si(2.5)/Graphite composite along with insito generated Li2O demonstrate a superior anodic behavior and delivers a reversible capacity of 340 mAh/g with a high coulombic efficiency (98%). The higher silicon content Cu(1)Fe(1)Si(3.5) along with graphite could not sustain capacity with cycling possibly due to ineffective buffer action of the anode constituents.