Lithium ion cells using a new high capacity cathode

Grincourt, Yves; Storey, C.; Davidson, Isobel

doi:10.1016/s0378-7753(01)00750-9

Cited by 28 publications

(18 citation statements)

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“…Two representative NMC compounds with nominal values of overlithiation degree x = 0 and x = 0.1 were therefore synthesized and compared. We confirmed the differences between the two compounds in the charge/ discharge curves at high potentials, as reported in the literature [7][8][9][10][11]. The high voltage region was then examined for both NMC compounds with Differential Electrochemical Mass Spectrometry (DEMS), an on-line analytic method detecting gaseous and volatile reaction products.…”

Section: Introductionsupporting

confidence: 81%

Direct evidence of oxygen evolution from Li1+x (Ni1/3Mn1/3Co1/3)1−x O2 at high potentials

et al. 2008

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Li 1+x (Ni 1/3 Mn 1/3 Co 1/3 ) 1-x O 2 (NMC) oxides are among the most promising positive electrode materials for future lithium-ion batteries. A voltage ''plateau'' was observed on the first galvanostatic charging curve of NMC in the extended voltage region positive to 4.5 V vs. Li/Li + for compounds with x [ 0 (overlithiated compounds). Differences were observed in the cycling stability of the overlithiated and stoichiometric (x = 0) NMC oxides in this potential region. A differential plot of the charge vs. potential profile in the first cycle revealed that, for the overlithiated compounds, a large irreversible oxidative peak arises positive to 4.5 V vs. Li/Li + , while in the same potential region only a small peak due to the electrolyte oxidation is detected for the stoichiometric material. Differential Electrochemical Mass Spectrometry (DEMS) was used to investigate the high voltage region for both compounds and experimental evidence for oxygen evolution was provided for the overlithiated compounds at potentials positive to 4.5 V vs. Li/Li + . No oxygen evolution was detected for the stoichiometric compound.

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Section: Introductionsupporting

confidence: 81%

Direct evidence of oxygen evolution from Li1+x (Ni1/3Mn1/3Co1/3)1−x O2 at high potentials

et al. 2008

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“…superstructure, the slabs cannot be completely ordered. The presence of a similar superstructure was recently reported for the Li͓Ni x Li ͑1/3−2x/3͒ Mn ͑2/3−x/3͒ ͔O 2 ͑x = 0, 1/3, and 1/2͒ materials by Meng et al 21 [24][25][26][27][28][29] suggesting that these electrochemical characteristics are linked to overlithiation. As shown in Fig.…”

supporting

confidence: 81%

Electron Diffraction Study of the Layered Li[sub y](Ni[sub 0.425]Mn[sub 0.425]Co[sub 0.15])[sub 0.88]O[sub 2] Materials Reintercalated after Two Different States of Charge

Weill

Tran²,

Martin³

et al. 2007

Electrochem. Solid-State Lett.

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A long and irreversible plateau is observed for Li 1.12 ͑Ni 0.425 Mn 0.425 Co 0.15 ͒ 0.88 O 2 . The layered Li y ͑Ni 0.425 Mn 0.425 Co 0.15 ͒ 0.88 O 2 ͑y = 0.93 and 0.73͒ materials were prepared by discharging to 3.2 V Li//Li y ͑Ni 0.425 Mn 0.425 Co 0.15 ͒ 0.88 O 2 cells charged up to 4.4 V ͑beginning of the plateau͒ and 4.8 V ͑end of the plateau͒, respectively. The structure was investigated using the combination of X-ray and electron diffraction experiments to study a possible structural evolution upon cycling of the superstructure observed for the pristine material. The disappearance of the superlattice lines in the 19.5-34°͑2 Cu ͒ range in the X-ray diffraction pattern as well as that of the diffuse disorder scattering lines ͑or the extra spots͒ in the electron diffraction patterns were clearly observed for Li 0.73 ͑Ni 0.425 Mn 0.425 Co 0.15 ͒ 0.88 O 2 . These results revealed the loss of the ͱ 3·a hex. ϫ ͱ 3·a hex. superstructure and thus of the cation ordering within the slabs when the Li//Li 1.12 ͑Ni 0.425 Mn 0.425 Co 0.15 ͒ 0.88 O 2 cells are charged to the end of the plateau. Moreover, other new diffuse disorder scattering lines were observed along the c * axis itself for the Li 0.73 ͑Ni 0.425 Mn 0.425 Co 0.15 ͒ 0.88 O 2 material that has seen the plateau, which were attributed to local interslab space thickness variations. ͒O 2 ͑x = 0, x = 1/6͒ materials have made these layered materials recognized as promising positive electrode materials for lithium-ion batteries due to their high reversible capacity and their very good safety characteristics. 1-3 Since then, many reports have addressed these types of compounds. [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] As reported in previous papers, 18-20 the structure of the Li 1+x ͑Ni 0.425 Mn 0.425 Co 0.15 ͒ 1−x O 2 phases was carefully characterized in our lab by the combination of X-ray, neutron, and electron diffraction. The X-ray and neutron diffraction data showed a decreasing nickel amount in the interslab space and an increasing lithium amount in the slab with increasing overlithiation ͑x͒. Electron diffraction results indicated for the Li 1+x ͑Ni 0.425 Mn 0.425 Co 0.15 ͒ 1−x O 2 ͑x = 0 and 0.12͒ materials the presence of an in-plane ͱ 3·a hex. ϫ ͱ 3·a hex. superstructure in the slabs, which was previously suggested by the presence of small diffraction lines observed in the 19.5-34°͑2 Cu ͒ range in their X-ray diffraction ͑XRD͒ patterns. 20 Due to the material stoichiometry and to their difference in size ͓r͑Li + ͒ = 0.72 Å, r͑Co 3+ ͒ = 0.53 Å; r͑Mn 4+ ͒ = 0.54 Å, r͑Ni 2+ ͒ = 0.69 Å, and r͑Ni 3+ ͒ = 0.56 Å͔, the cations present in the slabs for Li 1+x ͑Ni 0.425 Mn 0.425 Co 0.15 ͒ 1−x O 2 were shown to be ordered among two distinct sites, ␣ and ␤, to minimize the constraints: the large Li + and Ni 2+ ions were expected to occupy the ␣ site while the small Mn 4+ , Ni 3+ and Co 3+ ions should occupy the ␤ site. Note that due to a ratio between the amounts of large and small cations present in the slabs, significantly different from one-half e...

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“…Recently, Davidson et al developed the solid solution series Li x Cr y Mn 22y O 41z , including Li 1.2 Cr 0.4 Mn 0.4 O 2 . 4,5 Subsequently, Dahn et al intensively attempted to stabilize the layered structure by using a solid solution between Li[Li 1/3 Mn 2/3 ]O 2 and LiMO 2 , such as Li[Ni x Li (122x)/3 Mn (22x)/3 ]O 2 , Li[Co x Li (12x)/3 Mn (222x)/3 ]O 2 , and Li[Cr x Li (12x)/3 Mn (222x)/3 ]O 2 . [6][7][8][9] Fe-containing Li[Li 1/3 Mn 2/3 ]-O 2 was also investigated as a cathode material.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and electrochemical properties of nanocrystalline Li[Ni_xLi_(1−2x)/3Mn_(2−x)/3]O₂prepared by a simple combustion method

et al. 2004

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Nanocrystalline Li[Ni x Li (122x)/3 Mn (22x)/3 ]O 2 powders were prepared by a simple combustion method and investigated using X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS), scanning electron microscopy (SEM), particle size analysis (PSA), and galvanostatic charge/discharge cycling. According to the XRD analysis, single-phase compounds with a layered structure were obtained for powders with 0 ¡ x ¡ 0.25, while mixtures were obtained for powders with 0.30 ¡ x ¡ 0.50. Rietveld analysis revealed that single-phase Li[Ni x Li (122x)/3 Mn (22x)/3 ]O 2 is basically a layered rock-salt structure in which a small amount of Ni occupies the 3a sites. The initial discharge capacity of a Li/Li[Ni x Li (122x)/3 Mn (22x)/3 ]O 2 cell with x ~0.20 was about 288 mA h g 21 , corresponding to about 91% of the theoretical value, when it was cycled in the voltage range of 4.8-2.0 V with a specific current of 20 mA g 21 at 30 uC. As far as we know, charge/discharge cycling on an Li/Li[Ni 0.20 Li 0.20 Mn 0.60 ]O 2 cell gives the highest discharge capacity of 288 mA h g 21 among the LiMO 2 -based (M ~Co, Ni, and Mn) cathode materials. A very promising factor for high-rate capability applications was an excellent rate capability in continuous cycling at specific currents ranging from 20 mA g 21 to 900 mA g 21 , due to the nanocrystalline particle size of 80-200 nm. The origin of the 4.5 V plateau was investigated by means of weight loss measurement and XAS for the charged/discharged electrodes. The weight loss measurement for the charged electrodes gave indirect evidence that the 4.5 V plateau did not originate from the ejection of oxygen. In XAS, the Mn oxidation state of 41 did not change during the charge/discharge process, and surprisingly the Ni did not further oxidize beyond about 31.

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Lithium ion cells using a new high capacity cathode

Cited by 28 publications

References 1 publication

Direct evidence of oxygen evolution from Li1+x (Ni1/3Mn1/3Co1/3)1−x O2 at high potentials

Direct evidence of oxygen evolution from Li1+x (Ni1/3Mn1/3Co1/3)1−x O2 at high potentials

Electron Diffraction Study of the Layered Li[sub y](Ni[sub 0.425]Mn[sub 0.425]Co[sub 0.15])[sub 0.88]O[sub 2] Materials Reintercalated after Two Different States of Charge

Synthesis and electrochemical properties of nanocrystalline Li[Ni_xLi_(1−2x)/3Mn_(2−x)/3]O₂prepared by a simple combustion method

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Lithium ion cells using a new high capacity cathode

Cited by 28 publications

References 1 publication

Direct evidence of oxygen evolution from Li1+x (Ni1/3Mn1/3Co1/3)1−x O2 at high potentials

Direct evidence of oxygen evolution from Li1+x (Ni1/3Mn1/3Co1/3)1−x O2 at high potentials

Electron Diffraction Study of the Layered Li[sub y](Ni[sub 0.425]Mn[sub 0.425]Co[sub 0.15])[sub 0.88]O[sub 2] Materials Reintercalated after Two Different States of Charge

Synthesis and electrochemical properties of nanocrystalline Li[NixLi(1−2x)/3Mn(2−x)/3]O2prepared by a simple combustion method

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Synthesis and electrochemical properties of nanocrystalline Li[Ni_xLi_(1−2x)/3Mn_(2−x)/3]O₂prepared by a simple combustion method