19F NMR of antimony and arsenic pentafluoride-graphite derivatives

Facchini, L.; Bouat, J.; Sfihi, H.; Legrand, A.P.; Furdin, G.; Melin, J.; Vangélisti, R.

doi:10.1016/0379-6779(82)90041-8

Cited by 15 publications

(4 citation statements)

References 22 publications

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“…− or SbF 6 − , also intercalation of AsF 5 /SbF 5 and AsF 3 /SbF 3 species into graphite has been reported. [72][73][74] However, in our work, no other species like PF 5 or other fluorophosphates could be identified in the charged graphite electrodes, which is in accordance to earlier reports. [44][45][46] Furthermore, no significant stage dependence of the 19 F chemical shift is observed, even though highly oxidizing potentials of ≈5 V vs Li|Li + are reached for the stage 1-GICs.…”

Section: Scansupporting

confidence: 93%

Editors’ Choice—Mechanistic Elucidation of Anion Intercalation into Graphite from Binary-Mixed Highly Concentrated Electrolytes via Complementary ¹⁹F MAS NMR and XRD Studies

Haneke

Frerichs

Heckmann

et al. 2020

J. Electrochem. Soc.

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Dual-graphite batteries have emerged as promising candidate for sustainable energy storage due to their potentially low costs and absence of toxic materials. However, the mechanism of anion intercalation and the structures of the resulting graphite intercalation compounds (GICs) are still not well understood. Here, we systematically evaluate the anion intercalation characteristics into graphite for three highly concentrated electrolytes containing LiPF6, LiTFSI and their equimolar binary mixture. The binary mixture exhibits a significantly enhanced capacity retention and improved intercalation kinetics compared to the single-salt electrolytes in graphite ∣∣ Li metal cells. In situ X-ray diffraction studies prove the formation of stage 1-GICs and a homogeneous distribution of anions within graphite. From ex situ solid-state 19F magic-angle spinning (MAS) nuclear magnetic resonance (NMR) measurements, GICs can be identified at various states-of-charge (SOCs). The 19F chemical shifts of intercalated anions indicate no significant charge transfer between anion and graphite. The observed narrow 19F linewidths of the GIC-signals are most likely caused by a high translational and/or rotational mobility of the intercalates. Furthermore, the 19F MAS NMR studies allow the identification of the molar ratios for PF6 − and TFSI− anions intercalated into graphite, suggesting a preferred intercalation of PF6 − anions, especially at lower SOCs.

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Section: Scansupporting

confidence: 93%

Editors’ Choice—Mechanistic Elucidation of Anion Intercalation into Graphite from Binary-Mixed Highly Concentrated Electrolytes via Complementary ¹⁹F MAS NMR and XRD Studies

Haneke

Frerichs

Heckmann

et al. 2020

J. Electrochem. Soc.

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“…The SbF~ was intercalated on graphite and the species we detect electrochemically have diffused out of the solid into the bulk electrolyte. While SbF~ intercalated graphite is known to contain mostly (>90%) SbF~, low levels of SbF3 and SbFC may also be present (12,13). Essentially all of the SbFs is weakly bound to the surface and readily washes off (14), thus explaining the small SbF3 reduction peak in our solution.…”

Section: Electrolyte Reactivity Toward LI At Open Circuit--lisbf6mentioning

confidence: 77%

Electrochemical Stability of LiMF6 ( M = P , As , Sb ) in Tetrahydrofuran and Sulfolane

Nanjundiah

Goldman

Dominey

et al. 1988

J. Electrochem. Soc.

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LiAsF6 is the current state-of-the-art lithium salt for use in many prototype rechargeable systems. The instability and potential toxicity of LiAsF6 has led to the search for new lithium salts. To this end, we investigated the electrochemical stability of LiSbF6 and LiPF~ in aprotic organic solvents. Electrochemical Studies, conductivity measurements, and open-circuit stability tests were conducted on LiSbF6 in tetrahydrofuran and sulfolane. Cyclic voltammetric studies of SbF6 were compared with those of AsF6-and PF6-anions. Sb(V) was reduced to Sb(III), and then to Sb(0). AsFc was reduced to AsF3, while no reduction of PF6-was observed. Reduction products of AsF6 and SbFC passivated the glassy carbon electrode, presumably due to LiF precipitation. Peak potentials were observed to shift in the positive direction as a function of concentration. This was accounted for on the basis of a follow-up chemical reaction.Because of its commercial availability in high purity, LiAsF~ is one of the most popular supporting electrolytes used today in ambient temperature rechargeable Li batteries. Nevertheless, the AsF6-anion is known to be chemically and electrochemically unstable in a reducing environment (1-3). Of greater potential concern for the consumer market is the toxicity of As(0), one of many AsFc reduction products (4). In order to better understand the chemistry of AsF~-anions in particular, and MFC anions in general, we set out to explore the electrochemistry of PFC, AsF6-, and SbF6 in common aprotic organic solvents. To this end, cyclic voltammetry (CV) and polarography were conducted at glassy carbon (GC) and the dropping mercury electrode (DME), respectively. In addition, the stability of the SbF6 containing electrolytes with Li at open-circuit voltage (OCV) at 70~ was studied.

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“…We have already mentioned that two fluorine popoulations with different mobilities have been observed by different NMR techniques by several authors [8,91. We have particularly studied arsenic and antimony pentafluoride GIC by continuous wave 1 9 F NMR at low temperature [10]. A broad and a narrow line can be seen.…”

Section: Discussionmentioning

confidence: 98%

“…On the other hand, 19F NMR has shown an evolution with temperature of two fluorine populations with different mobilities in arsenic and antimony pentafluoride GIC [8,9,10].…”

Section: Introductionmentioning

confidence: 98%

Populations of Fluorine and Arsenic in AsF₅-Graphite Intercalation Compounds

et al. 1982

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19F NMR of antimony and arsenic pentafluoride-graphite derivatives

Cited by 15 publications

References 22 publications

Editors’ Choice—Mechanistic Elucidation of Anion Intercalation into Graphite from Binary-Mixed Highly Concentrated Electrolytes via Complementary ¹⁹F MAS NMR and XRD Studies

Editors’ Choice—Mechanistic Elucidation of Anion Intercalation into Graphite from Binary-Mixed Highly Concentrated Electrolytes via Complementary ¹⁹F MAS NMR and XRD Studies

Electrochemical Stability of LiMF6 ( M = P , As , Sb ) in Tetrahydrofuran and Sulfolane

Populations of Fluorine and Arsenic in AsF₅-Graphite Intercalation Compounds

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19F NMR of antimony and arsenic pentafluoride-graphite derivatives

Cited by 15 publications

References 22 publications

Editors’ Choice—Mechanistic Elucidation of Anion Intercalation into Graphite from Binary-Mixed Highly Concentrated Electrolytes via Complementary 19F MAS NMR and XRD Studies

Editors’ Choice—Mechanistic Elucidation of Anion Intercalation into Graphite from Binary-Mixed Highly Concentrated Electrolytes via Complementary 19F MAS NMR and XRD Studies

Electrochemical Stability of LiMF6 ( M = P , As , Sb ) in Tetrahydrofuran and Sulfolane

Populations of Fluorine and Arsenic in AsF5-Graphite Intercalation Compounds

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Editors’ Choice—Mechanistic Elucidation of Anion Intercalation into Graphite from Binary-Mixed Highly Concentrated Electrolytes via Complementary ¹⁹F MAS NMR and XRD Studies

Editors’ Choice—Mechanistic Elucidation of Anion Intercalation into Graphite from Binary-Mixed Highly Concentrated Electrolytes via Complementary ¹⁹F MAS NMR and XRD Studies

Populations of Fluorine and Arsenic in AsF₅-Graphite Intercalation Compounds