7Li NMR study on Li+ ionic diffusion and phase transition in Li CoO2

Nakamura, Kōichi; Ohno, Hideki; Okamura, Keisuke; Michihiro, Yoshitaka; Moriga, Toshihiro; Nakabayashi, Ichiro; Kanashiro, Tatsuo

doi:10.1016/j.ssi.2006.02.021

Cited by 60 publications

(60 citation statements)

References 18 publications

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“…Therefore, N 1 = 6, N 2 = 3, s 1 is equivalent to the a-axis length, s 2 = a/ √ 3, Z v,1 = 0.27 for Li 0.73 CoO 2 , and Z v,2 = 1. As a result, we obtain D Li = (1.3 ± 0.1) × 10 −10 cm 2 /s for Li 0.73 CoO 2 at 300 K. The estimated D Li is found to be very consistent with the prediction by first-principle calculations [4], compared with the Li-NMR results obtained at 400 K [3,22] [see Fig. 5(b)].…”

Section: X Coo 2 [16]supporting

confidence: 85%

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Ion Diffusion in Solids Probed by Muon-Spin Spectroscopy

Sugiyama

2013

J. Phys. Soc. Jpn.

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Diffusion of Li+ ions in solids is a basic principle behind the operation of Li-ion batteries. Although a diffusion coefficient of Li + (D Li ) in solids is usually evaluated by 7 Li-NMR, difficulties arise for materials that contain magnetic ions. This is because the magnetic ions contribute additional spinlattice relaxation processes that are considerably larger than the 1/T 1 expected from only Li diffusion. As a result, it is very difficult to estimate correct D Li by Li-NMR, although D Li is one of the primary parameters that govern the charge and discharge rate of a Li-ion battery, particularly for the case of a future solid-state battery. We have, therefore, initiated to measure D Li in solids with muon-spin relaxation (µSR). Here, we summarize our µSR work on Li-diffusion and compare the µSR result with that obtained by QENS from the viewpoint of time window.

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Section: X Coo 2 [16]supporting

confidence: 85%

“…Sharp minima in the predicted curve (at x = 1/3 and 1/2) are caused by Li-ordering. The 7 Li-NMR result [3,22] for T = 400 K is also plotted (solid dot) for comparison. the measurements below ambient T , it is not clear how to distinguish E a of the liquid electrolyte and E a of Li x CoO 2 .…”

Section: X Coo 2 [16]mentioning

confidence: 99%

Ion Diffusion in Solids Probed by Muon-Spin Spectroscopy

Sugiyama

2013

J. Phys. Soc. Jpn.

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“…This suggests that the change in the µ + SR parameters around 150 K is caused by an intrinsic change in Li x CoO 2 , but the change around 300 K is visible only by µ + SR. The increase in ν above 150 K is, thus, most unlikely due to µ + diffusion but it is rather due to Li + diffusion, i.e., either a freezing of the Li + motion or an order-disorder transition of the Li + ions occurs below around 150 K. This is also supported by a recent 7 Li-NMR experiment [20], in which the NMR line width -vs.-T curve for Li 0.6 CoO 2 exhibits a step-like decrease with T around 150 K by motional narrowing due to Li + diffusion. Since such diffusion naturally increases a local structural symmetry, it is reasonable that ∆ slightly decreases with T around 150 K. On the other hand, both Li + and µ + are inferred to be diffusing above 300 K, resulting in the large decrease in ∆ caused by motional narrowing.…”

Section: Resultssupporting

confidence: 68%

“…Sharp minima in the predicted curve (at x = 1/3 and 1/2) are caused by Li-ordering. The 7 Li-NMR result [5,20] for T = 400 K is also plotted (solid dot) for comparison.…”

Section: Resultsmentioning

confidence: 99%

A novel tool for detecting Li diffusion in solids containing magnetic ions;μ⁺SR study on Li_xCoO₂

Sugiyama

Mukai

Ikedo

et al. 2010

J. Phys.: Conf. Ser.

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Abstract. The diffusion coefficient of Li+ ions (DLi) in the battery material LixCoO2 has been investigated by means of muon-spin relaxation (µ + SR), because DLi for positive electrode materials has not been determined correctly so far. Based on performing the experiments in zerofield and weak longitudinal-fields at temperatures up to 400 K, we determined the fluctuation rate (ν) of the fields on the muons due to their interaction with the nuclear moments. Combined with susceptibility data and electrostatic potential calculations, clear Li + ion diffusion was detected above ∼ 150 K. The DLi estimated from ν was in very good agreement with predictions from first-principles calculations, and we present the µ + SR technique as a novel and optimal probe to detect DLi of unique usefulness for materials containing magnetic ions. IntroductionIn spite of a long research history on lithium insertion materials for Li-ion batteries [1, 2], e.g., LiCoO 2 , LiNiO 2 , and LiMn 2 O 4 , one of their most important intrinsic physical properties, the Li + ions diffusion coefficient (D Li ), has not yet been determined with any reliability. Although Li NMR is a powerful technique to measure D Li for non-magnetic materials, it is particularly difficult to evaluate D Li for materials containing magnetic ions, because the magnetic ions induce additional pathways for the spin-lattice relaxation rate (1/T 1 ), resulting in huge 1/T 1 compared with that expected for only the diffusive motion of Li ions.Such difficulty was clearly evident in the 1/T 1 (T ) curve for LiCoO 2 and LiNiO 2 [3,4], and, for that reason, D Li was instead estimated from the Li-NMR line width [5]. However, since the line width, i.e., the spin-spin relaxation rate (1/T 2 ) is also affected by the magnetic ions, the D Li obtained by Li-NMR for LiCoO 2 (= 1 × 10 −14 cm 2 s −1 at 400 K) is approximately four orders of magnitude smaller than predicted by first-principles calculations [6]. Since lithium insertion materials always include transition metal ions, in order to maintain charge neutrality during the extraction and/or insertion of Li + ions, it is consequently very difficult to determine D Li for these compounds unambiguously by Li-NMR.On the other hand, the chemical diffusion coefficient (D chem

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“…Similar studies on a different timescale can be carried out using NMR. 23,34,35 We describe the preparation of the samples and the general µSR technique in section II, including the details of how the low-temperature data were analysed. In sections III A, III B, and III C we present our µSR data and analysis.…”

Section: Introductionmentioning

confidence: 99%

Probing magnetic order in LiMPO4(M=Ni, Co, Fe) and lithium diffusion in Li
Baker¹,
Franke²,
Pratt³
et al. 2011
Phys. Rev. B
44
6
30
0
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Muon spin relaxation measurements are reported on three members of the Li x MPO 4 series. The magnetic properties of stoichiometric samples with M = Ni, Co, Fe, were investigated at low-temperature. In LiNiPO 4 we observe different forms of the muon decay asymmetry in the commensurate and incommensurate antiferromagnetic phases, accompanied by a change in the temperature dependence of the muon oscillation frequency. In LiCoPO 4 the form of the muon decay asymmetry indicates that the correlation between layers decreases as the Néel temperature is approached from below. LiFePO 4 shows more conventional behaviour, typical for an antiferromagnet. Measurements on Li x FePO 4 with x = 0.8, 0.9 & 1 show evidence for lithium diffusion below ∼ 250 K and muon diffusion dominating the form of the relaxation at higher temperature. The thermally activated form of the observed hopping rate suggests an activation barrier for lithium diffusion of ∼ 100 meV and a diffusion constant of D Li ∼ 10 −10 − 10 −9 cm 2 s −1 at room temperature.

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7Li NMR study on Li+ ionic diffusion and phase transition in Li CoO2

Cited by 60 publications

References 18 publications

Ion Diffusion in Solids Probed by Muon-Spin Spectroscopy

Ion Diffusion in Solids Probed by Muon-Spin Spectroscopy

A novel tool for detecting Li diffusion in solids containing magnetic ions;μ⁺SR study on Li_xCoO₂

Probing magnetic order in LiMPO4(M=Ni, Co, Fe) and lithium diffusion in Li
Baker¹,
Franke²,
Pratt³
et al. 2011
Phys. Rev. B
44
6
30
0
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7Li NMR study on Li+ ionic diffusion and phase transition in Li CoO2

Cited by 60 publications

References 18 publications

Ion Diffusion in Solids Probed by Muon-Spin Spectroscopy

Ion Diffusion in Solids Probed by Muon-Spin Spectroscopy

A novel tool for detecting Li diffusion in solids containing magnetic ions;μ+SR study on LixCoO2

Probing magnetic order in LiMPO4(M=Ni, Co, Fe) and lithium diffusion in LiBaker1, Franke2, Pratt3 et al. 2011Phys. Rev. B446300View full textAdd to dashboardCite

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A novel tool for detecting Li diffusion in solids containing magnetic ions;μ⁺SR study on Li_xCoO₂

Probing magnetic order in LiMPO4(M=Ni, Co, Fe) and lithium diffusion in Li
Baker¹,
Franke²,
Pratt³
et al. 2011
Phys. Rev. B
44
6
30
0
View full text Add to dashboard Cite