• Title/Summary/Keyword: LiNi0.6Mn0.2Co0.2O2

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Enhanced Performance in a Lithium-ion Battery via the Crystal-aligned LiNi0.6Mn0.2Co0.2O2 and the Relevant Electrochemical Interpretation (결정배향 LiNi0.6Mn0.2Co0.2O2 전극활물질을 통한 리튬이차전지 성능 향상 및 이의 전기화학적 해석)

  • Cham, Kim
    • Journal of the Korean Chemical Society
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    • v.66 no.6
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    • pp.451-458
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    • 2022
  • Through the crystal alignment research based on the magnetic properties of LiNixMnyCo1-(x+y)O2 such as magnetic susceptibility and related anisotropy, a crystal aligned LiNi0.6Mn0.2Co0.2O2 electrode is obtained, in which the (00l) plane is frequently oriented perpendicular to the surface of a current collector. The crystal aligned LiNi0.6Mn0.2Co0.2O2 electrode steadily exhibits low electrode polarization properties during the charge/discharge process in a lithium-ion battery, thus affording an improved capacity compared to a pristine LiNi0.6Mn0.2Co0.2O2 electrode. The aligned LiNi0.6Mn0.2Co0.2O2 electrode may have an appropriate structural nature for fast lithium-ion transport due to the oriented (00l) plane, and thus it contributes to enhancing the battery performance. This enhancement is analyzed in terms of various electrochemical theories and experiment results; thus, it is verified to occur because of the considerably fast lithium-ion transport in the aligned LiNi0.6Mn0.2Co0.2O2 electrode.

Highly stabilized microstructure and excellent electrochemical performances of Ni-rich LiNi0.9Co0.05Mn0.05O2 cathode via La modification (La 개질을 통한 Ni-rich LiNi0.9Co0.05Mn0.05O2 양극재의 고도로 안정화된 미세구조 및 우수한 전기화학적 성능)

  • Seung-Hwan, Lee
    • Journal of Industrial Technology
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    • v.42 no.1
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    • pp.1-5
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    • 2022
  • Although the mileage of electric vehicles can be increased based on the excellent energy density of the LiNi0.9Co0.05Mn0.05O2, it is known that the reason for limiting its use is the low lifespan and poor surface stability due to the structural deformation of the LiNi0.9Co0.05Mn0.05O2. To improve the structural stability of LiNi0.9Co0.05Mn0.05O2, electrochemical performance is improved by La coating on the surface. La-modified LiNi0.9Co0.05Mn0.05O2 shows an initial capacity of 210.6 mAh/g, a capacity retention rate of 89.9 % after 50 cycles, and a retention rate of 52.5% at 6.0 C. These are superior performances than the pristine sample, because the structural stability of the LiNi0.9Co0.05Mn0.05O2 cathode is improved by the La coating.

Synthesis and electrochemical properties of layered $Li[Ni_xCo_{1-2x}Mn_x]O_2$ materials for lithium secondary batteries prepared by mechanical alloying (기계적 합금법을 이용한 리튬 2차 전지용 층상 양극물질 $Li[Ni_xCo_{1-2x}Mn_x]O_2$ 의 합성 및 전기화학적 특성에 관한 연구)

  • 박상호;신선식;선양국
    • Proceedings of the Korea Crystallographic Association Conference
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    • 2002.11a
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    • pp.16-16
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    • 2002
  • The presently commercialized lithium-ion batteries use layer structured LiCoO₂ cathodes. Because of the high cost and toxicity of cobalt, an intensive search for new cathode materials has been underway in recent years. Recently, a concept of a one-to-one solid state mixture of LiNO₂ and LiMnO₂, i.e., Li[Ni/sub 0.5/Mn/sub 0.5/]O₂, was adopted by Ohzuku and Makimura to overcome the disadvantage of LiNiO₂ and LiMnO₂. Li[Ni/sub 0.5/Mn/sub 0.5/]O₂ has the -NaFeO₂ structure, which is characteristic of the layered LiCoO₂ and LiNiO₂ structures and shows excellent cycleability with no indication of spinel formation during electrochemical cycling. Layered Li[Ni/sub x/Co/sub 1-2x/Mn/sub x/]O₂ (x = 0.5 and 0.475) materials with high homogeneity and crystallinity were synthesized using a mechanical alloying method. The Li[Ni/sub 0.475/Co/sub 0.05/Mn/sub 0.475/]O₂ electrode delivers a high discharge capacity of 187 mAh/g between 2.8 and 4.6 V at a high current density of 0.3 mA/㎠(30 mA/g) with excellent cycleability. The charge/discharge and differential capacity vs. voltage studies of the Li[Ni/sub x/Co/sub 1-2x/Mn/sub x/]O₂ (x = 0.5 and 0.475) materials showed only one redox peak up to 50 cycles, which indicates that structural phase transitions are not occurred during electrochemical cycling. The magnitude of the diffusion coefficients of lithium ions for Li[Ni/sub x/Co/sub 1-2x/Mn/sub x/]O₂(x = 0.5 and 0.475) are around 10/sup -9/ ㎠/s measured by the galvanostatic intermittent titration technique (GITT).

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Study on Ti-doped LiNi0.6Co0.2Mn0.2O2 Cathode Materials for High Stability Lithium Ion Batteries (고안정성 리튬이온전지 양극활물질용 Ti 치환형 LiNi0.6Co0.2Mn0.2O2 연구)

  • Jeon, Young Hee;Lim, Soo A
    • Journal of the Korean Electrochemical Society
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    • v.24 no.4
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    • pp.120-132
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    • 2021
  • Although the development of high-Nickel is being actively carried out to solve the capacity limitation and the high price of raw cobalt due to the limitation of high voltage use of the existing LiCoO2, the deterioration of the battery characteristics due to the decrease in structural stability and increase of the Ni content. It is an important cause of delaying commercialization. Therefore, in order to increase the high stability of the Ni-rich ternary cathod material LiNi0.6Co0.2Mn0.2O2, precursor Ni0.6Co0.2Mn0.2-x(OH)2/xTiO2 was prepared using a nanosized TiO2 suspension type source for uniform Ti substitution in the precursor. It was mixed with Li2CO3, and after heating, the cathode active material LiNi0.6Co0.2Mn0.2-xTixO2 was synthesized, and the physical properties according to the Ti content were compared. Through FE-SEM and EDS mapping analysis, it was confirmed that a positive electrode active material having a uniform particle size was prepared through Ti-substituted spherical precursor and Particle Size Analyzer and internal density and strength were increased, XRD structure analysis and ICP-MS quantitative analysis confirmed that the capacity was effectively maintained even when the Ti-substituted positive electrode active material was manufactured and charging and discharging were continued at high temperature and high voltage.

The Synthesis of Na0.6Li0.6[Mn0.72Ni0.18Co0.10]O2 and its Electrochemical Performance as Cathode Materials for Li ion Batteries

  • Choi, Mansoo;Jo, In-Ho;Lee, Sang-Hun;Jung, Yang-Il;Moon, Jei-Kwon;Choi, Wang-Kyu
    • Journal of Electrochemical Science and Technology
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    • v.7 no.4
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    • pp.245-250
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    • 2016
  • The layered $Na_{0.6}Li_{0.6}[Mn_{0.72}Ni_{0.18}Co_{0.10}]O_2$ composite with well crystalized and high specific capacity is prepared by molten-salt method and using the substitution of Na for Li-ion battery. The effects of annealing temperature, time, Na contents, and electrochemical performance are investigated. In XRD analysis, the substitution of Na-ion resulted in the P2-$Na_{2/3}MO_2$ structure ($Na_{0.70}MO_{2.05}$), which co-exists in the $Na_{0.6}Li_{0.6}[Mn_{0.72}Ni_{0.18}Co_{0.10}]O_2$ composites. The discharge capacities of cathode materials exhibited $284mAhg^{-1}$ with higher initial coulombic efficiency.

Enhanced Electrochemical Properties of All-Solid-State Batteries Using a Surface-Modified LiNi0.6Co0.2Mn0.2O2 Cathode

  • Lim, Chung Bum;Park, Yong Joon
    • Journal of Electrochemical Science and Technology
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    • v.11 no.4
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    • pp.411-420
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    • 2020
  • Undesirable interfacial reactions between the cathode and sulfide electrolyte deteriorate the electrochemical performance of all-solid-state cells based on sulfides, presenting a major challenge. Surface modification of cathodes using stable materials has been used as a method for reducing interfacial reactions. In this work, a precursor-based surface modification method using Zr and Mo was applied to a LiNi0.6Co0.2Mn0.2O2 cathode to enhance the interfacial stability between the cathode and sulfide electrolyte. The source ions (Zr and Mo) coated on the precursor-surface diffused into the structure during the heating process, and influenced the structural parameters. This indicated that the coating ions acted as dopants. They also formed a homogenous coating layer, which are expected to be layers of Li-Zr-O or Li-Mo-O, on the surface of the cathode. The composite electrodes containing the surface-modified LiNi0.6Co0.2Mn0.2O2 powders exhibited enhanced electrochemical properties. The impedance value of the cells and the formation of undesirable reaction products on the electrodes were also decreased due to surface modification. These results indicate that the precursor-based surface modification using Zr and Mo is an effective method for suppressing side reactions at the cathode/sulfide electrolyte interface.

Material Life Cycle Assessment of Graphene 2wt% Added to Li1.6Ni0.35Mn0.65O2 Half-Cell (그래핀 2wt%를 첨가한 Li1.6Ni0.35Mn0.65O2 Half-Cell의 물질 전 과정 평가)

  • CHO, KYOUNG-WON;LEE, YOUNG-HWAN;HAN, JEONG-HEUM;YU, JAE-SEON;HONG, TAE-WHAN
    • Transactions of the Korean hydrogen and new energy society
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    • v.31 no.1
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    • pp.132-137
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    • 2020
  • Lithium secondary batteries have become an important power source for portable electronic devices such as cellular phones, laptop computers. Presently, commercialized lithium-ion batteries use a LiCoO2 cathode. However, due to the high cost and environmental problems resulting from cobalt, an intensive search for new electrode materials is being actively conducted. Recently, solid solution LiMn1-xNixO2 have become attractive because of high capacity and enhanced safety at high voltages over 4.5 V. The Li1.6Ni0.35Mn0.65O2 compounds were conventionally prepared by a sol-gel method, which can produce the layered Li-Ni-Mn-O compounds with a high homogeneity. And by adding a graphene 2wt% the first charge-discharge voltage profiles was increased over Li1.6Ni0.35Mn0.65O2 compound. Also, the variation s of the discharge capacities with cycling showed a higher capacity retention rater. In this study, material lifecycle evaluation was performed to analyze the environmental impact characteristics of Li1.6Ni0.35Mn0.65O2 & graphene 2wt% half-cell manufacturing process. The software of material life cycle assessment was Gabi. Through this, environmental impact assessment was performed for each process. The environmental loads induced by Li1.6Ni0.35Mn0.65O2 & graphene 2wt% synthesis process were quantified and analyzed, and the results showed that the amount of power had the greatest impact on the environment.

The Structural and Electrochemical Properties of Li[Ni0.6-xBaxCo0.1Mn0.3]O2 (x = 0, 0.01) by Barium Doping (Barium 도핑에 따른 Li[Ni0.6-xBaxCo0.1Mn0.3]O2(x=0, 0.01) 의 구조 분석 및 전기화학적 특성)

  • Jang, Byeong-Chan;Yoo, Gi-Won;Yang, Su-Bin;Min, Song-Gi;Son, Jong-Tae
    • Journal of the Korean Electrochemical Society
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    • v.17 no.4
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    • pp.222-228
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    • 2014
  • Ni-rich system $Li[Ni_{1-x-y}Co_xMn_y]O_2$ of lithium secondary battery cathode material keep a high discharge capacity. However, by the Ni content increases, there is a problem that the electrochemical properties and stability of the structure are reduced. In order to solve these problems, research for positive ion doping is performed. The one of the cathode material, barium-doped $Li[Ni_{0.6-x}Ba_xCo_{0.1}Mn_{0.3}]O_2$ (x=0.01), was synthesized by the precursor, $Ni_{0.6}Co_{0.1}Mn_{0.3}(OH)_2$, from the co-precipitation method. The barium doped materials have studied the structural and electrochemical properties. The analysis of structural properties, results of X-ray diffraction analysis, and those results confirmed the change of the lattice from the binding energy in the structure by barium doping. Increased stability of the layered structure was observed by $I_{(006)}+I_{(102)}/I_{(101)}$(R-factor) ratio decrease. we expected that the electrochemical characteristics are improved. 23 mAh/g discharge capacity of barium-doped $Li[Ni_{0.6-x}Ba_xCo_{0.1}Mn_{0.3}]O_2$ (x=0.01) electrode is higher than discharge capacity of $Li[Ni_{0.6}Co_{0.1}Mn_{0.3}]O_2$ due to decrease overvoltage. And, through the structural stability was confirmed that improved the cycle characteristics. We caused a reduction in charge transfer resistance between the electrolyte and the electrode was confirmed that the C-rate characteristics are improved.

Structures and Electrochemical Properties of LiNi0.5-xCo2x}Mn0.5-xO2 as Cathode Materials for Lithium-ion Batteries

  • Choi, Hyun-Chul;Kim, Ho-Jin;Jeong, Yeon-Uk;Jeong, Soo-Hwan;Cheong, In-Woo;Jung, Uoo-Chang
    • Bulletin of the Korean Chemical Society
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    • v.30 no.11
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    • pp.2603-2607
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    • 2009
  • $LiNi_{0.5-x}Co_{2x}Mn_{0.5-x}O_{2}$ (x = 0, 0.1, 1/6, 1.2, 0.3) were synthesized by the solid-state reaction method. The crystal structure was analyzed by X-ray powder diffraction and Rietveld refinement. $LiNi_{0.5-x}Co_{2x}Mn_{0.5-x}O_{2}$ samples give single phases of hexagonal layered structures with a space group of R-3m for x = 0.1, 1/6, 0.2, and 0.3. The lattice constants of a and c-axis were decreased with the increase in Co contents in samples. The thickness of MO2 slab was decreased and inter-slab distance was increased with the increase in Co contents in $LiNi_{0.5-x}Co_{2x}Mn_{0.5-x}O_{2}$. According to XPS analysis, the valence states of Mn, Co, and Ni in the sample are mainly +4, +3, and +3, respectively. The discharge capacity of 202 mAh/g at 0.1C-rate in the potential range of 4.7 - 3.0 V was obtained in $LiNi_{0.3}Co_{0.4}Mn_{0.3}O_2$ sample, and $LiNi_{0.4}Co_{0.2}Mn_{0.4}O_2$ gives excellent cycle performance in the same potential range.

Effects of Calcinations Temperature on the Electrochemical Properties of Li[Ni0.6Co0.2Mn0.2]O2 Lithium-ion Cathode Materials (리튬 이차전지용 양극활물질 Li[Ni0.6Co0.2Mn0.2]O2의 소성 온도가 전기화학적 특성에 미치는 영향)

  • Yoo, Gi-Won;Jeon, Hyo-Jin;Son, Jong-Tae
    • Journal of the Korean Electrochemical Society
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    • v.16 no.2
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    • pp.59-64
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    • 2013
  • Using $Na_2CO_3$ and $MeSO_4$ (Me = Ni, Co and Mn) as starting materials, the precursor of $[Ni_{0.6}Co_{0.2}Mn_{0.2}]CO_3$ has been synthesized by carbonate co-precipitation. The precursor was mixed with $Li_2CO_3$, and calcined at 750, 850, and$950^{\circ}C$ in air. Effect of calcinations temperature on characteristics of $Li[Ni_{0.6}Co_{0.2}Mn_{0.2}]O_2$ cathode materials was investigated. The structure and characteristics of $Li[Ni_{0.6}Co_{0.2}Mn_{0.2}]O_2$ were determined by X-ray diffraction (XRD), Scanning electron microscopy (SEM) and electrochemical measurements. The X-ray diffraction (XRD) results show that the intensity ratio of $I_{(003)}/I_{(104)}$ increased and the R-factor ratio decreased with the increase of calcinations temperature. And Scanning electron microscopy (SEM) result show that the primary particle size increased. Especially, the $Li[Ni_{0.6}Co_{0.2}Mn_{0.2}]O_2$ calcined at $950^{\circ}C$ for 24 H shows excellent electrochemical performances with reversible specific capacity of $165.3mAhg^{-1}$ [cut-off voltage 2.5~4.3 V, 0.1 C($17mAhg^{-1}$)] and good capacity retention of 95.4% after 50th charge/discharge cycles[cut-off voltage 2.5~4.3 V, 1 C($170mAhg^{-1}$)].