• Title, Summary, Keyword: $Li_4Ti_5O_{12}$

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Synthesis and Electrochemical Characteristics of Spherical Li4Ti5O12/CNT Composite Materials for Hybrid Capacitors

  • Yang, Joeng-Jin;Kim, Yu-Ri;Jeong, Moon-Gook;Yuk, Yong-Jae;Kim, Han-Joo;Park, Soo-Gil
    • Journal of Electrochemical Science and Technology
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    • v.6 no.2
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    • pp.59-64
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    • 2015
  • Spherical Li4Ti5O12 and Li4Ti5O12 carbon nanotube (CNT) composites were synthesized using a colloid system. The electrochemical properties of the composites were thoroughly examined to determine their applicability as hybrid capacitor anodes. The electrical conductivity of the spherical Li4Ti5O12-CNT composite was improved over that of the spherical Li4Ti5O12 composite. The synthesized composites were utilized as the anode of a hybrid capacitor, which was assembled with an activated carbon (AC) positive electrode. The CNTs attached on the spherical Li4Ti5O12 particles contributed to a 51% reduction of the equivalent series of resistance of the Li4Ti5O12-CNTs/AC hybrid capacitor compared to the Li4Ti5O12/AC hybrid capacitor. Moreover, the Li4Ti5O12-CNTs/AC hybrid capacitor showed a larger capacitance than the Li4Ti5O12/AC hybrid capacitor; specifically, the Li4Ti5O12-CNT/AC hybrid capacitor showed 1.6 times greater capacitance at 40 cycles with a 10 mA cm−2 loading current density.

The Electric Properties of Surface Coating with CePO4 and M3(PO4)2 (M=Mg, Zn) on Li4Ti5O12 for Energy Storage Capacitor

  • Lee, Jong-Kyu;Yoon, Jung-Rag
    • Journal of Electrical Engineering and Technology
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    • v.13 no.1
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    • pp.413-417
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    • 2018
  • The $Li_4Ti_5O_{12}$ of anode material for the hybrid capacitor was coated using $CePO_4$, $M_3(PO_4)_2$ (M=Mg, Zn). The capacitance of phosphate coated $Li_4Ti_5O_{12}$ was found to be lower than that of $Li_4Ti_5O_{12}$, whereas the equivalent series resistance was higher than that of $Li_4Ti_5O_{12}$. With an increase in cycle number, the base of cylindrical cell exhibited swelling due to gas generated from the reaction between $Li_4Ti_5O_{12}$ and electrolyte. The swelling cycle number of phosphate coated $Li_4Ti_5O_{12}$ was higher than that of $Li_4Ti_5O_{12}$ due to improvement in electrochemical stability. Based on the results, it is proposed that phosphate coating can be employed as a barrier layer to control the gassing reaction by isolating the $Li_4Ti_5O_{12}$ particle from electrolyte solution.

Electrochemical Characteristics of Hybrid Capacitor using Core-shell Structure of MCMB/Li4Ti5O12 Composite (Core-shell 구조의 MCMB/Li4Ti5O12 합성물을 사용한 하이브리드 커패시터의 전기화학적 특성)

  • Ko, Hyoung Shin;Choi, Jeong Eun;Lee, Jong Dae
    • Korean Chemical Engineering Research
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    • v.52 no.1
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    • pp.52-57
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    • 2014
  • The MCMB-$Li_4Ti_5O_{12}$ with core-shell structure was prepared by sol-gel process to improve low cycle capability of MCMB in this study. The electrochemical characteristics were investigated for hybrid capacitor using MCMB-$Li_4Ti_5O_{12}$ as the negative electrode and $LiMn_2O_4$, Active carbon fiber as the positive electrode. The electrochemical behaviors of hybrid capacitor using organic electrolytes ($LiPF_6$, EC/DMC/EMC) were characterized by charge/discharge, cyclic voltammetry, cycle and impedance tests. The hybrid capacitor using MCMB-$Li_4Ti_5O_{12}/LiMn_2O_4$ electrodes had better capacitance than MCMB hybrid systems and was able to deliver a specific energy with 67 Wh/kg at a specific power of 781 W/kg.

Manufacturing and Electrochemical Characteristics of SnO2/Li4Ti5O12 for Lithium Ion Battery (리튬이차전지용 SnO2/Li4Ti5O12의 합성 및 전기화학적 특성)

  • Yang, A-Reum;Na, Byung-Ki
    • Clean Technology
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    • v.21 no.4
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    • pp.265-270
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    • 2015
  • In order to increase the capacity of the lithium ion battery, the capacity of the anode should be increased. SnO2 and Li4Ti5O12 were studied to replace the graphite as the anode materials. In this study, SnO2/Li4Ti5O12 composite materials were synthesized by solid-state method. The study reported here attempts to enhance the electrochemical capacity of Li4Ti5O12 through the incorporation of SnO2. Sn-based Li ion storage materials are loaded on Li4Ti5O12 surface. The SnO2/Li4Ti5O12 composite material has higher capacity than Li4Ti5O12, but the cycling capacity was decreased due to SnO2.

Electrochemistry Characteristics of $Li_4Ti_5O_{12}$ Anode Electrode for Li-ion Battery (리튬전지용 $Li_4Ti_5O_{12}$ 음극전극의 전기화학적 특성)

  • Oh, Mi-Hyun;Kim, Han-Joo;Kim, Young-Jae;Son, Won-Keun;Lim, Kee-Joe;Park, Soo-Gil
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.340-341
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    • 2005
  • Lithium titanium oxide as anode material for energy storage prepared by novel synthesis method. $Li_4Ti_5O_{12}$ based spinel-framework structures are of great interest material for lithium-ion batteries. We describe here $Li_4Ti_5O_{12}$ a zero-strain insertion material was prepared by novel sol-gel method and by high energy ball milling (HEBM) of precursor to from nanocrystalline phases. According to the X-ray diffraction and scanning electron microscopy analysis, uniformly distributed $Li_4Ti_5O_{12}$ particles with grain sizes of 100nm were synthesized. Lithium cells, consisting of $Li_4Ti_5O_{12}$ anode and lithium cathode showed the 173 mAh/g in the range of 1.0 $\sim$ 3.0 V. Furthermore, the crystalline structure of $Li_4Ti_5O_{12}$ didn't transfer during the lithium intercalation and deintercalation process.

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Electrochemical Characteristics of Cr Added Li4Ti5O12 Prepared by Sol-gel Method (졸-겔법으로 합성한 Cr 첨가 Li4Ti5O12의 전기화학적 특성)

  • Kim, Sun-Ah;Cho, Woo-Ram;Jeong, Koo-Hyun;Cho, Byung-Won;Na, Byung-Ki
    • Journal of the Korean Electrochemical Society
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    • v.14 no.1
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    • pp.27-32
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    • 2011
  • The electorchemical properties of $Li_4Ti_5O_{12}$ added with Cr was tested. The addition or substitution of atoms to $Li_4Ti_5O_{12}$ are expected to modify the crystal structure, and therefore to change the electrochemical performances of $Li_4Ti_5O_{12}$. After the spinel structure $Li_4Ti_{5-x}Cr_xO_{12}$ (x = 0~0.2) were obtained via sol-gel method, the gel was heated in a muffle furnace at $800{\sim}850^{\circ}C$ for 12 h in air. The physical properties of the samples were characterized by TG-DTA, XRD, SEM, FT-IR, and the electrochemical properties were tested with battery cycler at 0.01~2.0 V range. The $Li_4Ti_5O_{12}$ exhibited 169.9 mAh/g at 1C and capacity recovery was 97.5% of the initial capacity at 0.1C. $Li_4Ti_{4.9}Cr_{0.1}O_{12}$ (Cr 1% added) showed best performance of 193.8 mAh/g at 1C and the capacity recovery was increased to 98.8% of the initial capacity at 0.1C.

Effects of post-calcination and mechanical pulverization on the electrochemical properties of nano-sized Li4Ti5O12 for hybrid capacitors

  • Lee, Byung-Gwan;Ahn, Hyo-Jin;Yoon, Jung-Rag
    • Current Applied Physics
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    • v.17 no.2
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    • pp.121-125
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    • 2017
  • Great efforts have been devoted for the synthesis of $Li_4Ti_5O_{12}$ nanoparticles as anode material, because particle size less than 100 nm is the main factor for achieving a high rate capability. In this study, we fabricated nano-sized $Li_4Ti_5O_{12}$ by high-energy milling operated at 3500 rpm, that it was treated afterwards by post-calcination to improve its pulverized crystallinity. Post-calcination at moderate temperature is found to be effective for improving the electrochemical properties of $Li_4Ti_5O_{12}$ prepared by mechanical pulverization. Finally, a 100 nm-sized $Li_4Ti_5O_{12}$ was successfully obtained by optimizing the high-energy milling passing 10 times in chamber and setting post-calcination to $700^{\circ}C$. The specific capacity significantly depended on the crystallinity of $Li_4Ti_5O_{12}$ after treated by the post-calcination. The 100 nm-sized $Li_4Ti_5O_{12}$ showed high-rate capability and good capacity retention of 99.9% after 1500 cycles. It can be explained by the synergistic effect of reduced particle size and improved crystallinity.

The Effect of Y Doping on Electrochemical Behavior of Spherical $Li_4Ti_5O_{12}$ for Li-ion Batteries

  • Ji, Mi-Jeong;Choe, Byeong-Hyeon
    • Proceedings of the Materials Research Society of Korea Conference
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    • pp.31.1-31.1
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    • 2011
  • $Li_4Ti_5O_{12}$ is emerging as a promising material with its good structure stability and little volume change during the electrochemical reaction. However, its electrochemical performance is significantly limited by low electronic or ionic conductivity. In addition, high tap density is needed forim proving its volumetric energy density and commercialization. To enhance these properties, the spherical-like $Li_4Ti_5O_{12}$ particles were synthesized and carried out doping with yttrium. Prepared Y-doped $Li_4Ti_5O_{12}$ as a anode material showed great capacity retention rate of 92% (5C/0.2C), compared with no dope done. Consequently, it was found that Y doping into $Li_4Ti_5O_{12}$ matrix reduces the polarization and resistance on SEI layer during the electrochemical reaction.

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Study of the Electrochemical Properties of Li4Ti5O12 Doped with Ba and Sr Anodes for Lithium-Ion Secondary Batteries

  • Choi, Byung-Hyun;Lee, Dae-Jin;Ji, Mi-Jung;Kwon, Young-Jin;Park, Sung-Tae
    • Journal of the Korean Ceramic Society
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    • v.47 no.6
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    • pp.638-642
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    • 2010
  • The spinel material $Li_4Ti_5O_{12}$ has attracted considerable attention as an anode electrode material for many battery applications owing to its light weight and high energy density. However, the real capacity of $Li_4Ti_5O_{12}$ powder as determined by the solid-state method is lower than the ideal capacity. In this study, we investigated the effect of the dopants in M-doped spinel $Ba_xLi_{4-2x}Ti_5O_{12}$(x=0.005, 0.05, 0.1) powders prepared by the solid-state reaction method and used as the anode material in lithiumion batteries. The results confirmed the effect of the Ba and Sr dopants on the powder properties of the spinel $Li_4Ti_5O_{12}$, which exhibited a pure spinel structure without any secondary phase in its XRD pattern. Moreover, the electrochemical properties of the spinel M-LTO materials were investigated using a half cell. The electrochemical data show that cells with anodes made of undoped $Li_4Ti_5O_{12}$ and Ba- and Sr-doped $Li_4Ti_5O_{12}$ have discharge capacities of 97, 130, and 112 mAh/g, respectively, at the first cycle. Moreover, the Ba- and Sr-doped spinel $Li_4Ti_5O_{12}$ demonstrated good properties in the mid-voltage range at 1.55 V, showing stable cyclic voltammogram properties which surpassed those of the same material without Ba or Sr at 1 C after 100 cycles.

Electrochemical Characteristics of Sn Added Li4Ti5O12 as an Anode Material (Sn이 첨가된 Li4Ti5O12 음극활물질의 전기화학적 특성)

  • Jeong, Choong-Hoon;Kim, Sun-Ah;Cho, Byung-Won;Na, Byung-Ki
    • Journal of the Korean Electrochemical Society
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    • v.14 no.1
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    • pp.16-21
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    • 2011
  • $Li_4Sn_xTi_{5-x}O_{12}$ was manufactured by high energy ball milling (HEBM) and used as an anode material for lithium ion battery. Various amount of $SnO_2$was added to $Li_4Ti_5O_{12}$ and heated at different temperatures. The purpose of this research was to see the effect of $SnO_2$ addition into $Li_4Ti_5O_{12}$. Manufactured samples were analyzed by TGA, XRD, SEM, PSA. Battery cycler was used to test the charge/discharge properties of active materials. Heat treatment temperature of $800^{\circ}C$ was needed to make a stable structure of $Li_4Sn_xTi_{5-x}O_{12}$ and the particle size distribution was $0.2{\sim}0.6\;{\mu}m$. Charge/discharge process was repeated for 50 cycles at room temperature. The initial capacity was 168mAh/g and the voltage plateau was observed at 1.55V(Li/$Li^+$).