Nanomicrostructure, chemical stability and abnormal transformation in ultrafine particles of oxidized tin

Shek, Chan Hung; Lai, J.K.L.; Lin, G.M.; Zheng, Yuzhen; Liu, W.H.

doi:10.1016/s0022-3697(96)00112-6

Cited by 61 publications

(31 citation statements)

References 9 publications

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“…[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: 50%

“…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 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.

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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...

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Section: Oxidation In Ambient Airsupporting

confidence: 50%

Section: Mössbauer Spectrometry Resultsmentioning

confidence: 99%

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.

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show abstract

“…Both tetragonal and orthorhombic phases of tin oxide were observed. The orthorhombic phase has been reported by other workers [4,[13][14][15]. The nonchopped tin oxide thin films showed presence of stable tin oxide tetragonal SnO phases with dominant (1 0 1) phase whereas vapour chopped tin oxide thin films showed presence of orthorhombic SnO 2 with dominant (1 1 3) phase.…”

Section: Methodssupporting

confidence: 72%

Physical properties of tin oxide thin films improved by vapour chopping

Patil

Puri

2008

Journal of Alloys and Compounds

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“…The orthorhombic phase is metastable (rather than unstable) at ambient pressure [13]. The orthorhombic phase has also been reported by some workers [14][15][16]. The SEM of vapour chopped and nonchopped tin oxide oxidized at 573 K for 60 min is shown in Fig.…”

Section: Structuralsupporting

confidence: 73%

Improvement in the mechanical properties of tin oxide thin films due to vapour chopping

Patil¹,

Puri²,

Puri³

2008

Journal of Alloys and Compounds

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Nanomicrostructure, chemical stability and abnormal transformation in ultrafine particles of oxidized tin

Cited by 61 publications

References 9 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

Physical properties of tin oxide thin films improved by vapour chopping

Improvement in the mechanical properties of tin oxide thin films due to vapour chopping

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