Probing surface valence, magnetic property, and oxide ion diffusion pathway in B-site ordered perovskite-type Ba2Ca0.67M0.33NbO6−δ (M Mn, Fe, Co)

Kan, Wang Hay; Dong, Pengcheng; Bae, Jong‐Sup; Adams, Stefan; Thangadurai, Venkataraman

doi:10.1016/j.ssi.2016.03.022

Cited by 8 publications

(6 citation statements)

References 55 publications

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“…It appears that, during the heat treatment, Ni was further reduced to a lower oxidation state which progressed from the surface toward the bulk. The formation of such a thin surface layer is not uncommon in metal oxides and is often attributed to the lower oxygen atom coordination number around the cations on the surface. , In the case of ss-L x MNO, the formation of a surface reduction layer may also be related to oxygen loss during the heat treatment. For the Mn L III -edge, the relative area of Mn L III,β (∼643.6 eV) to L III,α (∼654.0 eV) in FY mode remains unchanged with decreasing lithium content (Figure d), confirming that the valence state of Mn stays at 4+ in all samples and it is insensitive to the change of lithium content (Figure f).…”

Section: Resultsmentioning

confidence: 99%

Crystal Chemistry and Electrochemistry of Li_xMn_1.5Ni_0.5O₄ Solid Solution Cathode Materials

et al. 2017

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For ordered high-voltage spinel LiMn 1.5 Ni 0.5 O 4 (LMNO) with the P4 3 2 1 symmetry, the two consecutive twophase transformations at ∼4.7 V (vs Li + /Li), involving three cubic phases of LMNO, Li 0.5 Mn 1.5 Ni 0.5 O 4 (L 0.5 MNO), and Mn 1.5 Ni 0.5 O 4 (MNO), have been well-established. Such a mechanism is traditionally associated with poor kinetics due to the slow movement of the phase boundaries and the large mechanical strain resulting from the volume changes among the phases, yet ordered LMNO has been shown to have excellent rate capability. In this study, we show the ability of the phases to dissolve into each other and determine their solubility limit. We characterized the properties of the formed solid solutions and investigated the role of non-equilibrium single-phase redox processes during the charge and discharge of LMNO. By using an array of advanced analytical techniques, such as soft and hard X-ray spectroscopy, transmission X-ray microscopy, and neutron/X-ray diffraction, as well as bond valence sum analysis, the present study examines the metastable nature of solidsolution phases and provides new insights in enabling cathode materials that are thermodynamically unstable.

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Section: Resultsmentioning

confidence: 99%

Crystal Chemistry and Electrochemistry of Li_xMn_1.5Ni_0.5O₄ Solid Solution Cathode Materials

et al. 2017

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“…The valence state of Li, Mn, Ta, and O was arbitrarily assigned as +1, +3, +5, and −2 in the pristine sample. Such a method was successfully used to calculate ionic diffusion pathway in other energy systems …”

Section: Methodsmentioning

confidence: 99%

Evolution of Local Structural Ordering and Chemical Distribution upon Delithiation of a Rock Salt–Structured Li_1.3Ta_0.3Mn_0.4O₂ Cathode

Kan

Wei

Chen

et al. 2019

Adv Funct Materials

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Lithium-rich disordered rock-salt oxides have attracted great interest owing to their promising performance as Li-ion battery cathodes. While experimental and theoretical efforts are critical in advancing this class of materials, a fundamental understanding of key property changes upon Li extraction is largely missing. In the present study, single-crystal synthesis of a new disordered rock-salt cathode material, Li 1.3 Ta 0.3 Mn 0.4 O 2 (LTMO), and its use as a model compound to investigate Li concentration-driven evolution of local cationic ordering, charge compensation, and chemical distribution are reported. Through the combined use of 2D and 3D X-ray nanotomography, it is shown that Li removal accompanied by oxygen oxidation is correlated with the development of morphological defects such as particle cracking. Chemical heterogeneity, quantified by subparticle level distribution of Mn valence state, is minimal during Mn redox, which drastically increases upon the formation of cracks during oxygen redox. Density functional theory and bond valence sum mismatch calculations reveal the presence of local short-range ordering in the pristine oxide, which gradually disappears along with the extraction of Li. The study suggests that with cycling the transformation into true cation-disordered state can be expected, which likely impacts the voltage profile and obtainable energy density of the oxide cathodes.

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“…In this manuscript, we construct a comprehensive functional perovskite-type phase diagram for the BaO-CaO-Ta 2 O 5 system for a wide composition between 1000 and 1550 C. Finally, the bond valence energy landscapes were computed to estimate the diffusion pathways of H + and O 2À , 7,8,14,15,[45][46][47][48] to evaluate their usefulness in different energy storage and conversion applications. [49][50][51][52] To understand the distribution of different cations in the same crystallographically distinct sites, the supercells and their relative energies were also evaluated to understand if cationic clustering may be present.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of polymorphism and charge transport in a BaO–CaO–Ta₂O₅ perovskite phase diagram using TOF-neutron and synchrotron X-ray diffraction, the bond-valence method and impedance spectroscopy

et al. 2022

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Probing surface valence, magnetic property, and oxide ion diffusion pathway in B-site ordered perovskite-type Ba2Ca0.67M0.33NbO6−δ (M Mn, Fe, Co)

Cited by 8 publications

References 55 publications

Crystal Chemistry and Electrochemistry of Li_xMn_1.5Ni_0.5O₄ Solid Solution Cathode Materials

Crystal Chemistry and Electrochemistry of Li_xMn_1.5Ni_0.5O₄ Solid Solution Cathode Materials

Evolution of Local Structural Ordering and Chemical Distribution upon Delithiation of a Rock Salt–Structured Li_1.3Ta_0.3Mn_0.4O₂ Cathode

Evaluation of polymorphism and charge transport in a BaO–CaO–Ta₂O₅ perovskite phase diagram using TOF-neutron and synchrotron X-ray diffraction, the bond-valence method and impedance spectroscopy

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Probing surface valence, magnetic property, and oxide ion diffusion pathway in B-site ordered perovskite-type Ba2Ca0.67M0.33NbO6−δ (M Mn, Fe, Co)

Cited by 8 publications

References 55 publications

Crystal Chemistry and Electrochemistry of LixMn1.5Ni0.5O4 Solid Solution Cathode Materials

Crystal Chemistry and Electrochemistry of LixMn1.5Ni0.5O4 Solid Solution Cathode Materials

Evolution of Local Structural Ordering and Chemical Distribution upon Delithiation of a Rock Salt–Structured Li1.3Ta0.3Mn0.4O2 Cathode

Evaluation of polymorphism and charge transport in a BaO–CaO–Ta2O5 perovskite phase diagram using TOF-neutron and synchrotron X-ray diffraction, the bond-valence method and impedance spectroscopy

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Crystal Chemistry and Electrochemistry of Li_xMn_1.5Ni_0.5O₄ Solid Solution Cathode Materials

Crystal Chemistry and Electrochemistry of Li_xMn_1.5Ni_0.5O₄ Solid Solution Cathode Materials

Evolution of Local Structural Ordering and Chemical Distribution upon Delithiation of a Rock Salt–Structured Li_1.3Ta_0.3Mn_0.4O₂ Cathode

Evaluation of polymorphism and charge transport in a BaO–CaO–Ta₂O₅ perovskite phase diagram using TOF-neutron and synchrotron X-ray diffraction, the bond-valence method and impedance spectroscopy