Spinel‐Layered Core‐Shell Cathode Materials for Li‐Ion Batteries

Cho, Yong Hyun; Lee, Sanghan; Lee, Yongseok; Hong, Tae-Eun; Cho, Jaephil

doi:10.1002/aenm.201100239

Cited by 196 publications

(170 citation statements)

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“…1C was set at 185 mAg -1 and charge and discharge rates are same and three identical coin-cells were used for pristine sample test. [19][20][21][22], but increasing the Mn content increased the charge transfer resistance, resulting in decreased electrochemical performance (rate capability). On the contrary, increasing Mn content preserves initial structural integrity during the high-temperature heating as well as electrochemical cycling [23].…”

Section: Introductionmentioning

confidence: 99%

Improved Rate Capability and Thermal Stability of LiNi0.5Co0.2Mn0.3O2 Cathode Materials via Nanoscale SiP2O7 Coating

Lee

Ahn

Cho

et al. 2011

J. Electrochem. Soc.

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LiδPyOz–coated LiNi0.5Co0.2Mn0.3O2 cathode materials doped with P and Si ions were prepared by direction reaction of LiOH and SiP2O7-coated Ni0.5Co0.2Mn0.3(OH)2 precursors. The coated cathodes exhibited quite impressive results; rate capability was improved by almost 100% at a 7 C rate compared to pristine LiNi0.5Co0.2Mn0.3O2. Furthermore, the amount of heat generation at 4.5 V charge cut-off as a result of the evolution of oxygen was reduced by 79%, compared to pristine LiNi0.5Co0.2Mn0.3O2 sample.

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Section: Introductionmentioning

confidence: 99%

Improved Rate Capability and Thermal Stability of LiNi0.5Co0.2Mn0.3O2 Cathode Materials via Nanoscale SiP2O7 Coating

Lee

Ahn

Cho

et al. 2011

J. Electrochem. Soc.

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“…1 Recently, researchers have been developing new cathode materials called "coreshell" materials. [2][3][4][5][6][7][8] Core-shell materials are made by encapsulating one composition of a cathode material in a shell of a different composition. This is done to exploit the beneficial characteristics of each of the core and shell materials.…”

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confidence: 99%

Determination of Shell Thickness of Spherical Core-Shell Ni_xMn_1-x(OH)₂Particles via Absorption Calculations of X-Ray Diffraction Patterns

Camardese

McCalla

Abarbanel

et al. 2014

J. Electrochem. Soc.

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Two core-shell materials were made in a continuously stirred tank reactor, one with a Ni(OH) 2 core and a Ni 1/2 Mn 1/2 (OH) 2 shell and the other with a Ni 1/2 Mn 1/2 (OH) 2 core and a Ni 0.17 Mn 0.83 (OH) 2 shell. X-ray diffraction measurements (Cu K α radiation) of the core-shell materials were compared to reference materials which were physical mixtures with the same overall composition. The smaller core peaks in the XRD patterns of the core-shell materials were attributed to absorption of X-rays due primarily to the high manganese contents of the shells. Calculations were performed assuming spherical particles of radius matching results from SEM/EDS measurements. For a 5.5 μm radius particle with a Ni(OH) 2 core, the shell thickness was calculated from XRD patterns to be 0.47 ± 0.03 μm. For a 7.9 μm particle of the material with the Ni 1/2 Mn 1/2 (OH) 2 core, the shell was determined to be 1.77 ± 0.15 μm thick. Both these results were found to agree well with the overall composition of the samples as determined by elemental analysis and with spatial EDS measurements. This X-ray absorption modeling technique provides an experimentally simple way to measure the thickness of micron scale shell coatings while sampling all particles, unlike methods such as EDS. Future applications for lithium-ion batteries will demand higher energy density, improved safety, and improved lifetime all without sacrificing cost. The choice of cathode material used in a cell can have dramatic effects on energy density, safety, cost and lifetime.1 Recently, researchers have been developing new cathode materials called "coreshell" materials.2-8 Core-shell materials are made by encapsulating one composition of a cathode material in a shell of a different composition. This is done to exploit the beneficial characteristics of each of the core and shell materials. Ideally, the core material should have a low cost and high energy density. The shell material should show superior stability with the electrolyte, and hence should have very high coulombic efficiency. Combining two such materials would allow a cathode to have both high energy density and long lifetime. There have been many studies previously completed on homogeneous materials that are excellent candidates for both core and shell materials. 7,[9][10][11][12] Optimizing the core-shell motif requires careful consideration of the thickness of the shell coating. If the shell coating is too thin, coverage may be incomplete such that the core may be exposed to the electrolyte and additional parasitic reactions could then occur between the electrolyte and the core material and reduce the lifetime of the cell.13,11 Alternatively, if the shell is too thick the energy density will not be maximized.Measuring the thickness of the shell has been accomplished by other researchers through spatial spectroscopic composition techniques such as energy disperse spectroscopy (EDS).14 This procedure has been useful in proving that a shell is coating the core particles, however it has several disadvanta...

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“…9, 10 Zhu and Liu et al investigated the influence of Li content on structure and electrochemical performance of the layeredspinel composite material and emphasized the importance of experimental parameters. 11,12 Besides traditional co-precipitation, many other methods are used to prepare layered-spinel composite cathode materials, including the surface coating-induced method, 13 the self-combustion reaction, 14 the solvothermal method, 15 the sol-gel method, 16 spray-pyrolysis, 17 the poly(vinyl pyrrolidone) functional-coated method, 18,19 and the hydrothermal method. 1 Liu et al used the hydrothermal method to synthesize a nanostructured layered-spinel Li 1.13 Mn 0.75 Ni 0.25 O 2.32 , which has the advantages of simple preparation and controllable crystalline products.…”

Section: Introductionmentioning

confidence: 99%

Phase Component-controllable Synthesis of Layered-Spinel Composite Materials as High-Performance Cathode for Lithium-ion Battery

et al. 2016

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A layered-spinel composite cathode material, Li x Mn 0.75 Ni 0.25 O (1.75+x/2) , with controllable phase composition was synthesized by a hydrothermal method followed by calcination. Composite cathode materials that contained different amounts of spinel were synthesized by adjusting the reaction duration in the hydrothermal process. The spinel phase decreases with increasing reaction time, whereas the layered phase increases. ) and the best rate capability (105.3 mAh g −1 at 5 C), which can be ascribed to an appropriate content of layered and spinel phase; the layered component provides composite structural integrity and the spinel phase enables excellent rate performance.

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Spinel‐Layered Core‐Shell Cathode Materials for Li‐Ion Batteries

Cited by 196 publications

References 32 publications

Improved Rate Capability and Thermal Stability of LiNi0.5Co0.2Mn0.3O2 Cathode Materials via Nanoscale SiP2O7 Coating

Improved Rate Capability and Thermal Stability of LiNi0.5Co0.2Mn0.3O2 Cathode Materials via Nanoscale SiP2O7 Coating

Determination of Shell Thickness of Spherical Core-Shell Ni_xMn_1-x(OH)₂Particles via Absorption Calculations of X-Ray Diffraction Patterns

Phase Component-controllable Synthesis of Layered-Spinel Composite Materials as High-Performance Cathode for Lithium-ion Battery

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Spinel‐Layered Core‐Shell Cathode Materials for Li‐Ion Batteries

Cited by 196 publications

References 32 publications

Improved Rate Capability and Thermal Stability of LiNi0.5Co0.2Mn0.3O2 Cathode Materials via Nanoscale SiP2O7 Coating

Improved Rate Capability and Thermal Stability of LiNi0.5Co0.2Mn0.3O2 Cathode Materials via Nanoscale SiP2O7 Coating

Determination of Shell Thickness of Spherical Core-Shell NixMn1-x(OH)2Particles via Absorption Calculations of X-Ray Diffraction Patterns

Phase Component-controllable Synthesis of Layered-Spinel Composite Materials as High-Performance Cathode for Lithium-ion Battery

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Determination of Shell Thickness of Spherical Core-Shell Ni_xMn_1-x(OH)₂Particles via Absorption Calculations of X-Ray Diffraction Patterns