Improving the cycling stability of LiCoO2 at 4.5V through co-modification by Mg doping and zirconium oxyfluoride coating

Wang, Zhiguo; Wang, Zhixing; Guo, Huajun; Peng, Wenjie; Li, Xinhai

doi:10.1016/j.ceramint.2014.08.093

Cited by 46 publications

(31 citation statements)

References 29 publications

(33 reference statements)

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“…However, these suffer from several shortcomings, including a poor structural stability, an inability to extract all lithium ions and the high cost and toxicity of cobalt [9][10][11]. Therefore it is important to develop alternative cathode materials in order to obtain a higher capacity, improved safety and lower cost.…”

Section: Introductionmentioning

confidence: 99%

Properties of LiNi0.8Co0.1Mn0.1O2 as a high energy cathode material for lithium-ion batteries

Lee

2015

Korean J. Chem. Eng.

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Nickel-rich layered materials are prospective cathode materials for use in lithium-ion batteries due to their higher capacity and lower cost relative to LiCoO 2 . In this work, spherical Ni 0.8 Co 0.1 Mn 0.1 (OH) 2 precursors are successfully synthesized through a co-precipitation method. The synthetic conditions of the precursors -including the pH, stirring speed, molar ratio of NH 4 OH to transition metals and reaction temperature -are investigated in detail, and their variations have significant effects on the morphology, microstructure and tap-density of the prepared Ni 0.8 Co 0.1 Mn 0.1 (OH) 2 precursors. LiNi 0.8 Co 0.1 Mn 0.1 O 2 is then prepared from these precursors through a reaction with 5% excess LiOH· H 2 O at various temperatures. The crystal structure, morphology and electrochemical properties of the Ni 0.8 Co 0.1 Mn 0.1 (OH) 2 precursors and LiNi 0.8 Co 0.1 Mn 0.1 O 2 were investigated. In the voltage range from 3.0 to 4.3 V, LiNi 0.8 Co 0.1 Mn 0.1 O 2 exhibits an initial discharge capacity of 193.0 mAh g −1 at a 0.1 C-rate. The cathode delivers an initial capacity of 170.4 mAh g −1 at a 1 C-rate, and it retains 90.4% of its capacity after 100 cycles.

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Section: Introductionmentioning

confidence: 99%

Properties of LiNi0.8Co0.1Mn0.1O2 as a high energy cathode material for lithium-ion batteries

Lee

2015

Korean J. Chem. Eng.

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“…On the contrary, a few studies have reported no Mg migration in LCO. 15,21 Oxygen occupancy, 24 which may give confirmation of oxygen loss, was also not refined due to insufficient data.…”

Section: Varying the Upper Cutoff Voltage (Ucv)-figuresmentioning

confidence: 99%

“…These attempts have met varying degrees of success. 15,[20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] 15,[20][21][22][23]26,[28][29][30] Most studies attribute the improvements in LCO cycling performance to Mg either providing structural stability 15,21,26,27 or improving the conductivity of the material. 20,23,29,30 Recently, Shim et al reported a retention of 85% capacity after 500 cycles and 60% after 700 cycles in 2900 mAh prismatic full cells (LCO/graphite) cycling up to 4.4 V (4.48 V vs Li/Li + ) utilizing a combination of ionic conductor coating and Mg doping.…”

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confidence: 99%

“…[3][4][5][6][7][8][9] There are multiple causes for this drop in performance, including structural instability of highly delithiated LCO, [6][7][8]10,11 electrolyte oxidation [5][6][7]9,10,12,13 and Co dissolution. 3,5,7,8,14,15 To further understand the structural instability that arises from high voltage cycling, X-ray diffraction (XRD) has been instrumental in studying the unit cell lattice parameter changes and phase formations. 10,11,16,17 Theoretical work has also confirmed the majority of these occurrences and helped shed light in understanding phase formation at low lithium content.…”

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confidence: 99%

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Synthesis of Mg and Mn Doped LiCoO₂and Effects on High Voltage Cycling

Liu

Shunmugasundaram

et al. 2017

J. Electrochem. Soc.

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LiCo 1-2x Mg x Mn x O 2 (0 ≤ x ≤ 0.05) materials were prepared from Co 1-2x Mg x Mn x (OH) 2 (0 ≤ x ≤ 0.05) co-precipitated precursor materials by mixing precursor materials with stoichiometric amounts of Li 2 CO 3 and heating to 900 • C for 10 h. All precursor and lithiated materials were characterized by Scanning Electron Microscopy, X-ray Diffraction (XRD), Inductively Coupled PlasmaOptical Emissions Spectroscopy and electrochemical testing. In situ XRD was performed on LiCo 1-2x Mg x Mn x O 2 (x = 0, 0.02, 0.05) electrodes while cycling to study the effects of substitution on phase transitions and unit cell variations. Increasing Mg/Mn substitution in the material was found to slightly increase the 1 st charge capacity, decrease the 1 st discharge capacity and increase the 1 st cycle irreversible capacity (3.6 V-4.7 V). Cells with even 1% Mg/Mn doping were shown to have markedly improved cycling performance, and results suggest that the improvements stem from suppressing the cell impedance growth, not from the suppression of the O3-O6-O1 phase transitions. Lithium ion (Li-ion) batteries are used to power cell phones, laptops, other portable electronics, electric vehicles and grid storage. With an ever-increasing demand for energy, battery manufacturers and researchers constantly look for ways to increase the energy density while maintaining a long lifetime. LiCoO 2 (LCO) positive electrode materials, proposed by Mizushima et al. in 1980, 1 have been utilized since the commercialization of Li-ion battery technology by Sony in 1991. 2 Significant improvements have been made since then, but commercially available batteries never push LCO electrodes past 4.48 V (vs Li/Li + ), corresponding to the deintercalation/intercalation of ∼0.7 Li (per LCO) or a capacity of ∼190 mAh/g (out of a theoretical capacity of ∼274 mAh/g). In order to unlock more capacity and increase the energy density, the LCO electrodes have to cycle to voltages above 4.5 V (vs Li/Li + ). However, pushing cells with LCO electrodes to an even higher voltage result in a dramatic decrease in long term cycling performance. [3][4][5][6][7][8][9] There are multiple causes for this drop in performance, including structural instability of highly delithiated LCO,[6][7][8]10,11 electrolyte oxidation 5-7,9,10,12,13 and Co dissolution. 3,5,7,8,14,15 To further understand the structural instability that arises from high voltage cycling, X-ray diffraction (XRD) has been instrumental in studying the unit cell lattice parameter changes and phase formations. 10,11,16,17 Theoretical work has also confirmed the majority of these occurrences and helped shed light in understanding phase formation at low lithium content. 18,19 As Li deintercalates from LCO, the material undergoes a series of phase changes. The first is an insulatormetal transition, resulting in a 2-phase region. 10,16 As the material continues to deintercalate, LCO will undergo an order-disorder transition around 0.5 Li.16,18 Both of these transitions occur reversibly and are not detrimental to cycli...

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“…It can be seen apparently that Li 2 ZrO 3 -coated sample exhibit noticeably better rate performance than that of the bare sample, especially at high current densities (5C and 10C). These improvements are attributed to the Li 2 ZrO 3 coating layer which can delay the interface degradation between cathode and electrolyte even under high cutoff voltage [11].…”

Section: Resultsmentioning

confidence: 99%

Improving the cycling stability of LiCoO2 at 4.5V through co-modification by Mg doping and zirconium oxyfluoride coating

Cited by 46 publications

References 29 publications

Properties of LiNi0.8Co0.1Mn0.1O2 as a high energy cathode material for lithium-ion batteries

Properties of LiNi0.8Co0.1Mn0.1O2 as a high energy cathode material for lithium-ion batteries

Synthesis of Mg and Mn Doped LiCoO₂and Effects on High Voltage Cycling

Improvement of high voltage electrochemical performance of LiNi0.5Co0.2Mn0.3O2 cathode materials via Li2ZrO3 coating

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Improving the cycling stability of LiCoO2 at 4.5V through co-modification by Mg doping and zirconium oxyfluoride coating

Cited by 46 publications

References 29 publications

Properties of LiNi0.8Co0.1Mn0.1O2 as a high energy cathode material for lithium-ion batteries

Properties of LiNi0.8Co0.1Mn0.1O2 as a high energy cathode material for lithium-ion batteries

Synthesis of Mg and Mn Doped LiCoO2and Effects on High Voltage Cycling

Improvement of high voltage electrochemical performance of LiNi0.5Co0.2Mn0.3O2 cathode materials via Li2ZrO3 coating

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Synthesis of Mg and Mn Doped LiCoO₂and Effects on High Voltage Cycling