A novel concentration-gradient Li[Ni0.83Co0.07Mn0.10]O2 cathode material for high-energy lithium-ion batteries

Sun, Yang Kook; Lee, Boram; Noh, Hyung-Ju; Wu, Huiming; Myung, Seung‐Taek; Amine, Khalil

doi:10.1039/c0jm04242k

Cited by 133 publications

(83 citation statements)

References 21 publications

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“…We also demonstrated that this structural mismatch could be mitigated by nano-engineering of the core-shell material, where the shell exhibits a concentration gradient [14][15][16] . However, because of the short shell thickness, the manganese concentration at the outer layer of the particle is low; therefore, its effectiveness in stabilizing the surface of the material is weak, especially during high-temperature cycling (55 • C).…”

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confidence: 95%

Nanostructured high-energy cathode materials for advanced lithium batteries

et al. 2012

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Nickel-rich layered lithium transition-metal oxides, LiNi(1-x)M(x)O(2) (M = transition metal), have been under intense investigation as high-energy cathode materials for rechargeable lithium batteries because of their high specific capacity and relatively low cost. However, the commercial deployment of nickel-rich oxides has been severely hindered by their intrinsic poor thermal stability at the fully charged state and insufficient cycle life, especially at elevated temperatures. Here, we report a nickel-rich lithium transition-metal oxide with a very high capacity (215 mA h g(-1)), where the nickel concentration decreases linearly whereas the manganese concentration increases linearly from the centre to the outer layer of each particle. Using this nano-functional full-gradient approach, we are able to harness the high energy density of the nickel-rich core and the high thermal stability and long life of the manganese-rich outer layers. Moreover, the micrometre-size secondary particles of this cathode material are composed of aligned needle-like nanosize primary particles, resulting in a high rate capability. The experimental results suggest that this nano-functional full-gradient cathode material is promising for applications that require high energy, long calendar life and excellent abuse tolerance such as electric vehicles.

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confidence: 95%

Nanostructured high-energy cathode materials for advanced lithium batteries

et al. 2012

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“…As with our previous CS [11][12][13][14][15] and CGCS powder [16][17][18] products which demonstrated superior cyclabilities, a harsh environment is required in order to distinguish electrode materials exhibiting improved performances. Therefore, the fabricated cells were cycled at a constant current of 20 mA g À1 (0.1 C rate, (Figure 8 c).…”

Section: Electrochemical Evaluation Of Cgcs Powders With Nanoparticlementioning

confidence: 99%

“…Intimate contact among the nanorods is likely to improve the resulting electric conductivity. [17,18] This structure also exhibited both a high capacity, due to the nickel-rich core, and good structural and thermal stability, due to the manganese-rich outer layers, and therefore, a long life.…”

Section: Introductionmentioning

confidence: 97%

Nanorod and Nanoparticle Shells in Concentration Gradient Core–Shell Lithium Oxides for Rechargeable Lithium Batteries

et al. 2014

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The structure, electrochemistry, and thermal stability of concentration gradient core-shell (CGCS) particles with different shell morphologies were evaluated and compared. We modified the shell morphology from nanoparticles to nanorods, because nanorods can result in a reduced surface area of the shell such that the outer shell would have less contact with the corrosive electrolyte, resulting in improved electrochemical properties. Electron microscopy studies coupled with electron probe X-ray micro-analysis revealed the presence of a concentration gradient shell consisting of nanoparticles and nanorods before and after thermal lithiation at high temperature. Rietveld refinement of the X-ray diffraction data and the chemical analysis results showed no variations of the lattice parameters and chemical compositions of both produced CGCS particles except for the degree of cation mixing (or exchange) in Li and transition metal layers. As anticipated, the dense nanorods present in the shell gave rise to a high tap density (2.5 g cm(-3) ) with a reduced pore volume and surface area. Intimate contact among the nanorods is likely to improve the resulting electric conductivity. As a result, the CGCS Li[Ni0.60 Co0.15 Mn0.25 ]O2 with the nanorod shell retained approximately 85.5% of its initial capacity over 150 cycles in the range of 2.7-4.5 V at 60 °C. The charged electrode consisting of Li0.16 [Ni0.60 Co0.15 Mn0.25 ]O2 CGCS particles with the nanorod shell also displayed a main exothermic reaction at 279.4 °C releasing 751.7 J g(-1) of heat. Due to the presence of the nanorod shell in the CGCS particles, the electrochemical and thermal properties are substantially superior to those of the CGCS particles with the nanoparticle shell.

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“…The nickel-rich core delivers high reversible capacity, whereas the nickel-poor shell provides high thermal and cycling stability. Therefore, the NRC-CGS Li[NixCoyMn1-x-y]O2 materials exhibit promising electrochemical performance for LIBs [8,9]. However, due to the oxidation of nickel in the charging process, Ni 4+ is still present in the outermost surface of the NRC-CGS materials, which will react with the electrolyte, leading to undesirable capacity fading, especially at elevated temperatures.…”

Section: Introductionmentioning

confidence: 99%