Li4NiTeO6 as a positive electrode for Li-ion batteries

Abstract

and (ii) oxygen redox activity, provided that a high degree of Ni(3d)-O(2p) hybridization can be achieved. Li 4 NiTeO 6 was prepared by a conventional ceramic method from a stoichiometric mixture of Li 2 CO 3 (Aldrich), NiC 4 H 6 O 4 Á4H 2 O and TeO 2 (across organics) (2 : 1 : 1) annealed at about 1000 1C for 18 h, followed by heating at 1050 1C for 6 h with intermediate grinding. 10% Li 2 CO 3 was added in excess to compensate lithium loss due to high temperature heat treatment. The structure of the compound was analyzed by Rietveld refinement 7 using the Fullprof program 8 against high-resolution synchrotron powder diffraction data, collected on the 11-BM beamline at the Advanced Photon Source (APS, Argonne National Laboratory) with a wavelength of 0.4138 Å. Bragg peaks unambiguously indicate that the sample crystallizes in the C2/m space group with cell parameters a = 5.1584(1) Å, b = 8.8806(1) Å, c = 5.1366(1) Å and b = 110.241(1)1 (V = 220.777(3) Å 3 ), i.e. a cell similar to the one reported for Li 2 MnO 3 . 9 Refinements using different distributions of atoms within the layers led to a structure with Li layers alternating with honeycomb Li/Ni/Te layers (Fig. 1). In the latter, Li and Ni are statistically distributed in the same octahedral site (colored in yellow/green), surrounding TeO 6 octahedra (colored in blue). The final refinement which includes a strain analysis is shown in Fig. 1, and the deduced structural parameters are detailed in ESI † (Fig. S1, Tables S1 and S2).

Elucidating anionic oxygen activity in lithium-rich layered oxides

“…Similar absence of anionic oxygen activity was previously observed for Li 4 NiTeO 6 . 69 Participation of electrons from anionic oxygen can be traced to the electronic structure of metal and oxygen (M-O) bonding, including the unique Li-O-Li configuration in Li-rich metal oxides, because certain metal bonding (e.g., Li-O-Li) can lead to unhybridized O 2p states that promotes the participation of electrons from oxygen in charge compensation. 47 We note the Li content in our LNRO sample is not sufficient to allow all O to exist in a Li-O-Li configuration, which might subsequently influence the activation of anionic oxygen in LNRO.…”

Review—Li-Rich Layered Oxide Cathodes for Next-Generation Li-Ion Batteries: Chances and Challenges

“…To grasp further insight onto the (O 2 ) n− formation vs. O 2 release equilibrium, researchers went into a survey of Li 2 MO 3 materials. We will only refer to key Li 2 Ni 0.5 Te 0.5 O 3 , 146 Li 2 Ru 1-y Sn y O 3 , 143 Despite the above investigations, it was remaining impossible to visualize the deformation the oxygen sublattice resulting from the formation of the O-O peroxo-like dimmers. Such a failure was rooted i) in the fact that these compounds crystallized in the O3-type structure so that there are M atoms on top of the oxygen ones in contrast to an O1-type structure and ii) in the Li-driven motion of the metallic atoms upon oxidation.…”

K3LaTe2O9: a new alkali-rare earth tellurate with face-sharing TeO6 octahedra

“…[1][2][3][4] Generally, the Te stereochemistry plays an important role in determining the overall atomic and electronic structures and physical properties. [1][2][3][4] Generally, the Te stereochemistry plays an important role in determining the overall atomic and electronic structures and physical properties.…”