Electrochromism in lithiated Sn oxide: Mössbauer spectroscopy data on valence state changes

Isidorsson, J.; Granqvist, Claes G.; Häggström, Lennart; Nordström, Erik

doi:10.1063/1.363071

Cited by 23 publications

(15 citation statements)

References 79 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[23][24][25][26]30,39 The hyperfine parameters depend on the structure, and the parameters found here agree with those of amorphous Sn 2ϩ O 39 and of ultrafine oxidized Sn particles, 25 but not with those of crystalline tetragonal SnO. 40,41 We observed a curious small peak at 4 mm/s in the anode material undergoing oxidation.…”

Section: Oxidation In Ambient Airsupporting

confidence: 66%

“…This is in good agreement with published values: QS ϭ 0.50 mm/s, 23 QS ϭ 0.61 mm/s, 24 QS ϭ 0.55 or 0.56 mm/s, 25 QS ϭ 0. 56 mm/s, 26 and QS ϭ 0.54 mm/s 27 . The ␤-Sn spectrum at RT consists of a slightly broadened single line (⌫ ϭ 0.95 mm/s) with an isomer shift of 2.52 Ϯ 0.03 mm/s at RT.…”

Section: Mössbauer Spectrometry Resultsmentioning

confidence: 99%

“…The ␤-Sn can be distinguished, however, because the oxide spectra exhibit quadrupole splittings larger than 1 mm/s and often close to 2 mm/s. [23][24][25][26][27][28][29][30] The isomer shift increases by about 0.04 mm/s when ␤-Sn is cooled to 77 K. 31 Theoretical calculations 32 show that the isomer shift of ␤-Sn falls between the isomer shift of covalent ␣-Sn, 2.021 Ϯ 0.012 mm/s at RT, 28 and that of a hypothetical metallic face-centered cubic (fcc) Sn structure. A quadrupole splitting QS ϭ 0.41 Ϯ 0.04 mm/s is measured for ␤-Sn from the deconvoluted 11 K spectrum.…”

Section: Mössbauer Spectrometry Resultsmentioning

confidence: 99%

See 2 more Smart Citations

A [sup 119]Sn Mössbauer Spectrometry Study of Li-SnO Anode Materials for Li-Ion Cells

Hightower

Delcroix

Caër

et al. 2000

J. Electrochem. Soc.

View full text Add to dashboard Cite

A high specific energy has generated widespread scientific and technical interest in Li-ion cells for secondary batteries. This high specific energy density is derived from the high cell voltage, typically 4 V (vs. 1.3 V for a typical Ni-MH secondary battery). The Li densities in the cathode and anode materials are modest, however, and it is hoped that higher capacities of these electrodes will lead to further increases in the specific energies of Li-ion cells. Anode and cathode materials are now subjects of numerous investigations. [1][2][3] Huggins performed some early work on alloy anodes. 4,5 Recently, Ioda et al., of Fujifilm Celltec Co., Ltd., announced a new class of anode material comprising a composite Sn oxide glass. 6,7 These Sn oxide glasses have a reversible capacity of approximately twice that of carbon materials but unfortunately exhibit a large irreversible capacity and problems with capacity fade after tens of charge-discharge cycles.Early evidence was that the Li inserted in the Sn oxide glass material was ionic, 7 but Courtney et al. have provided convincing evidence for the formation of metallic Sn and Sn-Li alloys during Li insertion. [8][9][10] The general picture is that Li will reduce the Sn oxides to metallic Sn. Further studies on the mechanism of Li insertion in tin oxides and alloys have been performed by Mao et al. 11,12 with 119 Sn Mössbauer spectrometry measurements using a sealed cell. With increasing Li concentration in the anode material, a series of Li-Sn phases were observed by X-ray diffractometry, 13 including Li 22 Sn 5 , which represents an increase in volume over that of pure ␤-Sn by a factor of 3.6. Courtney and Dahn argued that since the increase in specific volume induces large local stresses, the cycle life of the electrode is poor when the Sn-rich regions in the electrode are large. [8][9][10][11][12][13] The role of microstructure on cycle life of Sn oxide anodes remains poorly understood, however.Althought the Fujifilm Celltec material has not yet been used for products in the marketplace, its promise has prompted a number of investigations into other Sn and Sn oxide materials that can be used as anodes in Li-ion cells. [9][10][11][12][13][14][15][16][17][18] One of the present authors has studied the insertion of Li into SnO,14 showing again that the Li served to reduce the Sn, and a Li-Sn alloy was formed at higher Li concentrations. Here we report results of 119 Sn Mössbauer spectrometry measurements at 11 and 300 K on partially and fully charged Li-SnO anode materials. We present detailed measurements of the recoil-free fractions (RFF) of the anode materials, and we show that the RFFs of the Sn oxide in the anode is anomalous, indicative of atomic-scale heterogeneities in the distribution of Sn atoms. Similar results are reported for the ␤-Sn in the anode material, although the contribution from the ␤-Sn is not definitively resolved from the Li 22 Sn 5 . We also present results from a study on the deterioration of Li-charged anode materials and Li-Sn alloys dur...

show abstract

Section: Oxidation In Ambient Airsupporting

confidence: 66%

Section: Mössbauer Spectrometry Resultsmentioning

confidence: 99%

Section: Mössbauer Spectrometry Resultsmentioning

confidence: 99%

See 1 more Smart Citation

A [sup 119]Sn Mössbauer Spectrometry Study of Li-SnO Anode Materials for Li-Ion Cells

Hightower

Delcroix

Caër

et al. 2000

J. Electrochem. Soc.

View full text Add to dashboard Cite

show abstract

“…Electrochromic Sn oxide films have been prepared by dip coating [9,10,11] and magnetron sputtering [12], and a change in the valence state of the tin atoms due to electrochemical Li + ion intercalation has been reported [13]. Sn oxide has the interesting property of being able to serve both as transparent conductor and noncoloring Li + ion conducting electrode, thereby giving the possibility to simplify the production of electrochromic devices.…”

Section: Introductionmentioning

confidence: 99%

Ellipsometry on sputter-deposited tin oxide films: optical constants versus stoichiometry, hydrogen content, and amount of electrochemically intercalated lithium

Isidorsson¹,

Granqvist²,

Rottkay³

et al. 1998

Appl. Opt.

View full text Add to dashboard Cite

Tin oxide thin films were deposited by reactive radio-frequency magnetron sputtering onto In(2)O(3):Sn-coated and bare glass substrates. Optical constants in the 3002500-nm wavelength range were determined by a combination of variable-angle spectroscopic ellipsometry and spectrophotometric transmittance measurements. Surface roughness was modeled from optical measurements and compared with atomic-force microscopy. The two techniques gave consistent results. The fit between experimental optical data and model results could be significantly improved when it was assumed that the refractive index of the Sn oxide varied across the film thickness. Varying the oxygen partial pressure during deposition made it possible to obtain films whose complex refractive index changed at the transition from SnO to SnO(2). An addition of hydrogen gas during sputtering led to lower optical constants in the full spectral range in connection with a blueshift of the bandgap. Electrochemical intercalation of lithium ions into the Sn oxide films raised their refractive index and enhanced their refractive-index gradient.

show abstract

“…The potential reaches a plateau at about 1.25 V, indicating a phase transition, 21 and a valence state change was observed by Mössbauer spectroscopy. 31 The potential drops slowly until it reaches 0.88 V, while the charge increases to 890 mC/cm 2 m. The normalized light scattering stays almost constant during this charging. Above 890 mC/cm 2 m, the potential increases, i.e., the potential creates a local minimum, which indicates a phase formation.…”

Section: Onset Of Electrodepositionmentioning

confidence: 92%

Adsorption and Electrodeposition on SnO[sub 2] and WO[sub 3] Electrodes in 1 M LiClO[sub 4]PC In Situ Light Scattering and In Situ Atomic Force Microscopy Studies

Isidorsson¹,

Lindström²,

Granqvist³

et al. 2000

J. Electrochem. Soc.

Self Cite

View full text Add to dashboard Cite

A novel spectroscopic in situ light scattering technique was used with in situ atomic force microscopy (AFM) to study electrode surfaces subjected to adsorption and electrodeposition. Tin dioxide and tungsten trioxide were used as electrodes in a 1 M LiClO 4 /propylene carbonate electrolyte. Both in situ methods showed the same increase in surface roughness immediately after the electrode was immersed in the electrolyte. The onset potential for electrodeposition could be determined; its specific value depended on the film composition as well as on the composition and purity of the electrolyte. A potential step technique revealed a progressive growth of the first electrodeposited layer. The growth mode after fully developed electrodeposition was characterized by a preferential growth of large crystals, evident from light scattering as well as AFM. Our experimental techniques make it possible to determine whether electrodeposition or electrochromism, due to electrochemical insertion of ionic species, dominates the observed modulation of the optical properties. The deposited layer was investigated using infrared spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Although the composition of this layer cannot be stated conclusively, it most likely contains lithium alkyl carbonate species.) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 35.8.191.249 Downloaded on 2015-04-03 to IP ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 35.8.191.249 Downloaded on 2015-04-03 to IP

show abstract

Electrochromism in lithiated Sn oxide: Mössbauer spectroscopy data on valence state changes

Cited by 23 publications

References 79 publications

A [sup 119]Sn Mössbauer Spectrometry Study of Li-SnO Anode Materials for Li-Ion Cells

A [sup 119]Sn Mössbauer Spectrometry Study of Li-SnO Anode Materials for Li-Ion Cells

Ellipsometry on sputter-deposited tin oxide films: optical constants versus stoichiometry, hydrogen content, and amount of electrochemically intercalated lithium

Adsorption and Electrodeposition on SnO[sub 2] and WO[sub 3] Electrodes in 1 M LiClO[sub 4]PC In Situ Light Scattering and In Situ Atomic Force Microscopy Studies

Contact Info

Product

Resources

About