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Komaba, Shinichi; Kumagai, Naoya; Baba, Mamoru; Miura, Fusayoshi; Fujita, Naotake; Groult, Henri; Devilliers, Didier; Kaplan, B.

doi:10.1023/a:1004047614084

Cited by 43 publications

(19 citation statements)

References 16 publications

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“…Numerous studies have reported various preparation methodologies, such as chemical route, radio frequency (r.f.). sputtering, sol–gel method, hydrothermal synthesis, synthesis of nanowires via chemical route, solid‐state combustion synthesis, freeze drying methods, and characterized the material for its functional properties such as electronic conductivity, lattice vibration, and so on . A characteristic of LMO that was reported only recently in 2016 is its ability to change its color due to Li intercalation .…”

Section: Introductionmentioning

confidence: 99%

Modulation of the Optical Properties of Lithium Manganese Oxide via Li‐Ion De/Intercalation

Joshi

Hadjixenophontos

Nowak

et al. 2018

Advanced Optical Materials

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a change in its optical constants during lithiation. However, a quantification of the optical properties and their tailoring via dis/charging has not been probed yet.The present study aims at the quantification of the optical constants, that is, the complex refractive index (CRI) and its change during intercalation by varying the lithium content of Li x Mn 2 O 4 from x = 0 to x = 1. Furthermore, an attempt is made to establish a link between this change in optical constants to the band structure of the material, learned from various sources. [11,15,[18][19][20][21] Similar characteristics have been reported for other electrochromic materials, such as Nb 2 O 5 , WO 3 , V 2 O 5 , and MoO 3, [22] which are known to change their optical properties, namely the real (n) and imaginary (k, or extinction coefficient) part of the CRI during an electrochemical reaction. In these materials, intercalation of charged species results in the generation of different electronic absorption bands in the optical spectrum or insertion of additional bound charges acting as harmonic oscillators. [22] For the present study, the reflection spectrum is measured at different stages of intercalation to clarify such electrochromic phenomenon. The measured spectra are evaluated to extract the CRI of the material for different lithium contents. Furthermore, an innovative method of recording the reflectance spectrum in situ during the electrochemical reaction is demonstrated (Figure 1c) that provides an additional time resolution to the spectrometry. Results Structural CharacterizationThe X-ray diffractogram (XRD) spectra of representative samples of LMO in the as-deposited and annealed states are shown in Figure 2a. No characteristic LMO diffraction peaks are observed for the as-deposited layer (bottom curve of Figure 2a). Only a small hump, observed at 61.98° (marked with *), could be due to the LMO structure corresponding to {440} planes. This reflection is very broad and shifted in comparison to the work of Wickhamt and Croft. [23] (JCP2 database) that predicts the position at 63.78°. The shape and the shift in the reflection suggest that the LMO layer is nanocrystalline and stressed, as it is usually the case for sputter-deposited layers.The optical response of lithium manganese oxide (LiMn 2 O 4 , LMO) on intercalation with Li ions is quantitatively characterized. For this purpose, a layer of LMO and a layer of platinum, acting as current collector/reflector, are deposited on oxidized silicon wafers. The active layer is structurally characterized using X-ray diffractogram and transmission electron microscopy. Well-defined intercalation states are prepared electrochemically and investigated by optical spectrometry in reflectance geometry. The measured dispersion curves are described by the Clausius-Mossotti dispersion equation to derive the complex refractive index as a function of wavelength and intercalation state. The observed variation of the effective resonant wavelength is consistent with the change in the band structure of LMO with l...

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Section: Introductionmentioning

confidence: 99%

Modulation of the Optical Properties of Lithium Manganese Oxide via Li‐Ion De/Intercalation

Joshi

Hadjixenophontos

Nowak

et al. 2018

Advanced Optical Materials

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“…Other in-situ studies were focused on reversible and irreversible transformations of stoichiometric LiMn 2 O 4 in air [16] or on in-situ X-ray diffraction (XRD) studies during lithium deintercalation from the spinel host structure [17]. rf magnetron sputtering is one promising method for synthesizing thin lithium manganese oxide films which have model character [18][19][20][21] and to study clearly their structural behavior due to the absence of carbon and binder as can be found in tape cast electrodes. Rapid laser annealing is one possible technique for crystallization of thin cathodes such as LiCoO 2 [22][23][24] or Li-Mn-O [20,21].…”

Section: Introductionmentioning

confidence: 99%

Comparative studies of laser annealing technique and furnace annealing by X-ray diffraction and Raman analysis of lithium manganese oxide thin films for lithium-ion batteries

et al. 2013

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“…Komaba et al [13] evaluated a positive electrode material by applying LiMn 2 O 4 active material on a stainless steel current collector. Stainless steels are still being employed as cell cases with uncertain chemistries.…”

Section: Introductionmentioning

confidence: 99%

Passivation behavior of Type 304 stainless steel in a non-aqueous alkyl carbonate solution containing LiPF6 salt

Sasaki

Saito

Sun

et al. 2009

Electrochimica Acta

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Passivation behavior of type 304 stainless steel in a non-aqueous alkyl carbonate solution containing LiPF 6 salt was studied using electrochemical polarization, X-ray photoelectron spectroscopy (XPS) and time of flight -secondary ion mass spectroscopy 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 2 confirmed by XPS. For complete elimination of the air-formed film, the surface of the stainless steel was scratched under anodic polarization conditions. At 3 V vs. Li/Li + where an anodic current peak appeared, only an indistinct layer was recognized on the newly scratched surface, according to ToF-SIMS analysis. Above 4 V vs. Li/Li + , substantial passive films were formed, which were composed of oxides and fluorides of iron and chromium. The origin of oxide was due to water contained in the non-aqueous alkyl carbonate solution, and that of fluorides were the result of the decomposition of electrolytic salt, LiPF 6 , especially at higher potential. The resultant passive films were stable in the non-aqueous alkyl carbonate solution containing LiPF 6 salt.

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Cited by 43 publications

References 16 publications

Modulation of the Optical Properties of Lithium Manganese Oxide via Li‐Ion De/Intercalation

Modulation of the Optical Properties of Lithium Manganese Oxide via Li‐Ion De/Intercalation

Comparative studies of laser annealing technique and furnace annealing by X-ray diffraction and Raman analysis of lithium manganese oxide thin films for lithium-ion batteries

Passivation behavior of Type 304 stainless steel in a non-aqueous alkyl carbonate solution containing LiPF6 salt

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