Solid-State Chemistry and Electrochemistry of LiCo[sub 1∕3]Ni[sub 1∕3]Mn[sub 1∕3]O[sub 2] for Advanced Lithium-Ion Batteries

Abstract

was prepared and characterized by scanning electron microscopy ͑SEM͒, high-resolution transmission electron microscopy ͑HRTEM͒, electron diffraction ͑ED͒, X-ray diffraction ͑XRD͒, and X-ray absorption fine structure ͑XAFS͒ to examine whether or not our first-principles calculation properly predicted a new lithium insertion material of LiCo 1/3 Ni 1/3 Mn 1/3 O 2 . High-resolution TEM image directly showed the layered structure having a cubic close-packed oxygen array. The ͓00.1͔-zone electron diffraction pattern showed a ͓ ͱ 3 ϫ ͱ 3͔R30°-type superlattice ordering in the transition metal layers. Rietveld analysis of powder XRD indicated that a structural model with a space group symmetry of P3 1 12 to present a ͓ ͱ 3 ϫ ͱ 3͔R30°-type superlattice based on ␣-NaFeO 2 -structural type was adequate rather than that simply formulated with R3 ¯m. The Me-O bond lengths, i.e., 1.93, 2.03, and 1.92 Å, respectively, for Co, Ni, and Mn, obtained by K-edge EXAFS, were compared with those calculated from structural data determined by XRD assuming P3 1 12 and also with those of the first-principles calculation. These values were consistent with each other, which indicated that LiCo 1/3 Ni 1/3 Mn 1/3 O 2 was a superlattice structure ͑P3 1 12; a = 4.959 Å, and c = 14.254 Å͒ consisting of Co 3+ ͑t 2g 6 e g 0 ͒, Ni 2+ ͑t 2g 6 e g 2 ͒, and Mn 4+ ͑t 2g 3 e g 0 ͒.

Effect of deviation from Ni/Mn stoichiometry in Li[Ni1/2Mn3/2]O4 upon rechargeable capacity at 4.7 V in nonaqueous lithium cells

“…2, the weak diffraction lines due to Ni6MnO8 are clearly observed at lower diffraction angles than (222) and (400) Fig. 2(b) LiNi1/2Mn1/2O2, 24) LiCo1/3Ni1/3Mn1/3O2, 25) and Li[Ni1/2Mn3/2]O4 under consideration.…”

Macroporous Li(Ni1/3Co1/3Mn1/3)O2: A High‐Power and High‐Energy Cathode for Rechargeable Lithium Batteries

“…[8,9,[11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] However, the mixed-hydroxide or carbonate method of synthesis is complex and the high capacity needs to be delivered at higher power (rate) and with improved capacity retention, than is the case to date. Here, we describe a simpler synthesis yielding a macroporous The maximum rate of lithium-ion diffusion in the solid state is limited, thus limiting the ability of lithium-ion cells to deliver high power (rate).…”

Ion Distributions and the Electrochemical Properties of LiNi_0.5Mn_0.5O₂ Prepared by Ion-Exchange for Positive Electrode

“…9 3 were mixed and then calcinated at 873 K for 12 h. The obtained powders were pressed into disks under a pressure of 0.490 MPa and sintered at 1173 K for 24 h in air. Finally, the precursor was allowed to react at 423, 553, 623, 723 K for from 10 min to 40 h by 0.5 M LiCl in 1-hexanol (the boiling point is 430 K) and the molten salt containing LiNO 3 and LiCl (eutectic point is 517 K).…”