XPS analysis of new lithium cobalt oxide thin-films before and after lithium deintercalation

Dupin, Jean‐Charles; Gonbeau, Danielle; Benqlilou-Moudden, Hanane; Vinatier, Philippe; Levasseur, Alain

doi:10.1016/s0040-6090(00)01802-2

Cited by 255 publications

(189 citation statements)

References 25 publications

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“…1 leaves no ambiguity as for the difference in surface reactivity of the two compounds. Such observation is in perfect agreement with previous results obtained using different techniques such as XPS and Fourier transform infrared (FTIR) [25][26][27][28][29].…”

Section: Resultssupporting

confidence: 92%

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Characterization of the surface of positive electrodes for Li-ion batteries using 7Li MAS NMR

Dupré¹,

Oliveri²,

Degryse³

et al. 2008

Ionics

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The growth and evolution of the interphase, due to contact with the ambient atmosphere or electrolyte, are followed using 7 Li magic-angle spinning nuclear magnetic resonance (MAS NMR) in the case of two materials amongst the most promising candidates for positive electrodes for lithium batteries: LiFePO 4 and LiMn 0.5 Ni 0.5 O 2 . The use of appropriate experimental conditions to acquire the NMR signal allows observing only the «diamagnetic» lithium species at the surface of the grains of active material. The reaction of LiMn 0.5 Ni 0.5 O 2 with the ambient atmosphere or LiPF 6 (1 M in Ethylene Carbonate/DiMéthyl Carbonate (EC/DMC)) electrolyte is extremely fast and leads to an important amount of lithium-containing diamagnetic species compared to what can be observed in the case of LiFePO 4 . The two studied materials display a completely different surface chemistry in terms of reactivity and/or kinetics of the surface towards electrolyte. Moreover, these results show that MAS NMR is a very promising tool to monitor phenomena taking place at the interface between electrode and electrolyte.

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Section: Resultssupporting

confidence: 92%

“…5). This confirms previous results concerning the higher stability of LiFePO 4 compared to LiNi 1/2 Mn 1/2 O 2 and their different surface chemistry [25][26][27][28][29][30], as suggested by XPS or FTIR.…”

Section: Resultssupporting

confidence: 92%

Characterization of the surface of positive electrodes for Li-ion batteries using 7Li MAS NMR

Dupré¹,

Oliveri²,

Degryse³

et al. 2008

Ionics

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“…In the XPS spectrum of Co 2p (Figure 3a), four peaks are present, which are fitted by two spinorbit doublets (P1, P2). They can be associated to Co 2p 1 [33,34] For the Ti 2p 1/2 /Ti 2p 3/2 and O 1s spectra given in Figure 3b, c, the two peaks centered at 458.5/452.8 eV (Figure 3b) are attributed to the Ti 4 + oxidation state [35] and the single peak exhibited in the XPS spectrum of O 1s (Figure 3c) Table 2. The peak area ratio of P1 to P2 of the Co 2p 1/2 electron is 2.65, which is in agreement with the XRD refinement result (Co 3 + /Co 4 + = 2.68).…”

Section: Resultsmentioning

confidence: 99%

Structure, Stoichiometry, and Electrochemical Performance of Li₂CoTi₃O₈ as an Anode Material for Lithium‐Ion Batteries

et al. 2013

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Li2CoTi3O8 powder has been synthesized by a simple citric nitrate method and was evaluated as an anode material for lithium‐ion batteries. The X‐ray diffraction (XRD) Rietveld refinement and X‐ray photoelectron spectroscopy (XPS) measurements indicate the existence of Ti‐site deficiency and a mixed‐valence state of Co ions in the Li2CoTi3O8 structure. The refined site‐occupation result gave a nonstoichiometric chemical formula of Li2CoTi2.682O8, which corresponds to a theoretical specific capacity of 322 mA h g−1, which is much higher than that of the stoichiometric material (233 mA h g−1). The synthesized Li2CoTi2.682O8 material exhibits high reversible capacity (ca. 320 mA h g−1), and excellent cycling stability and rate capability. A specific capacity of about 240 and 160 mA h g−1 can be achieved at 2 and 6 A g−1, respectively, by the Li2CoTi2.682O8 material. First‐principles calculation demonstrates that Ti‐site deficiency decreases the bandgap and thus facilitates the electron conduction.

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“…7a). Dupin et al [33] have discussed the XPS spectra of cobalt in Li 0.66 CoO 2 and LiCoO 2 systems in detail. Accordingly, Co 2p peaks appearing in the energy range 775-800 eV are actually built with signals from Co (3+) and (4+) states, i.e., a doublet with energy 779.8 and 795 eV corresponds to Co 3+ ions and the other at 781.5 and 796.8 eV belongs to Co 4+ ions.…”

Section: Co 2pmentioning

confidence: 99%

On the structural stability and oxygen permeation behavior of inorganic SrCo0.8Fe0.2O3−δ membranes

Kashyap

Jaiswal

Kumar

2016

Ionics

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The high oxygen permeability combined with reasonable structural stability of perovskite-type ABO 3−δ compounds is vital for their potential applications in gas separation, solid oxide fuel cells, sensors, etc. Hence, an attempt is made to develop SrCo 0.8 Fe 0.2 O 3−δ -based dense membranes with sol-gel-derived oxalates and study their phase stability and oxygen permeation. While X-ray diffraction confirms the presence of a perovskite-type cubic phase above 800°C, Xray photoelectron spectroscopy reveals the presence of cobalt and iron in 3+ and 4+ oxidation states with O 2 2− , O 2 − and O − species. The electrical conductivity increases up to a characteristic temperature and decreases slowly thereafter via pronounced carrier scattering. A 1.5-mm-thick membrane disp l a y s r e a s o n a b l e o x y g e n p e r m e a b i l i t y o f 1.05 × 10 −6 mol cm −2 s −1 at 900°C but has inadequate stability. Partial substitution of iron with zirconium is shown to improve permeability and stability significantly. Thus, SrCo 0.8 Fe 0.15 Zr 0.05 O 3−δ membrane shows promise for oxygen permeation purposes.

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XPS analysis of new lithium cobalt oxide thin-films before and after lithium deintercalation

Cited by 255 publications

References 25 publications

Characterization of the surface of positive electrodes for Li-ion batteries using 7Li MAS NMR

Characterization of the surface of positive electrodes for Li-ion batteries using 7Li MAS NMR

Structure, Stoichiometry, and Electrochemical Performance of Li₂CoTi₃O₈ as an Anode Material for Lithium‐Ion Batteries

On the structural stability and oxygen permeation behavior of inorganic SrCo0.8Fe0.2O3−δ membranes

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XPS analysis of new lithium cobalt oxide thin-films before and after lithium deintercalation

Cited by 255 publications

References 25 publications

Characterization of the surface of positive electrodes for Li-ion batteries using 7Li MAS NMR

Characterization of the surface of positive electrodes for Li-ion batteries using 7Li MAS NMR

Structure, Stoichiometry, and Electrochemical Performance of Li2CoTi3O8 as an Anode Material for Lithium‐Ion Batteries

On the structural stability and oxygen permeation behavior of inorganic SrCo0.8Fe0.2O3−δ membranes

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Structure, Stoichiometry, and Electrochemical Performance of Li₂CoTi₃O₈ as an Anode Material for Lithium‐Ion Batteries