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Names | |||
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IUPAC name
Lithium tetrafluoroborate
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Other names
Borate(1-), tetrafluoro-, lithium
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Identifiers | |||
3D model (
JSmol)
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ChemSpider | |||
ECHA InfoCard | 100.034.692 | ||
PubChem
CID
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UNII | |||
CompTox Dashboard (
EPA)
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Properties | |||
LiBF4 | |||
Molar mass | 93.746 g/mol | ||
Appearance | White/grey crystalline solid | ||
Odor | odorless | ||
Density | 0.852 g/cm3 solid | ||
Melting point | 296.5 °C (565.7 °F; 569.6 K) | ||
Boiling point | decomposes | ||
Very soluble [1] | |||
Hazards | |||
Occupational safety and health (OHS/OSH): | |||
Main hazards
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Harmful, causes burns, hygroscopic. | ||
NFPA 704 (fire diamond) | |||
Safety data sheet (SDS) | External MSDS | ||
Related compounds | |||
Other
anions
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Tetrafluoroborate, | ||
Related compounds
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Nitrosyl tetrafluoroborate | ||
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
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Lithium tetrafluoroborate is an inorganic compound with the formula Li BF4. It is a white crystalline powder. It has been extensively tested for use in commercial secondary batteries, an application that exploits its high solubility in nonpolar solvents. [2]
Although BF4− has high ionic mobility, solutions of its Li+ salt are less conductive than other less associated salts. [2] As an electrolyte in lithium-ion batteries, LiBF4 offers some advantages relative to the more common LiPF6. It exhibits greater thermal stability [3] and moisture tolerance. [4] For example, LiBF4 can tolerate a moisture content up to 620 ppm at room temperature whereas LiPF6 readily hydrolyzes into toxic POF3 and HF gases, often destroying the battery's electrode materials. Disadvantages of the electrolyte include a relatively low conductivity and difficulties forming a stable solid electrolyte interface with graphite electrodes.
Because LiBF4 and other alkali-metal salts thermally decompose to evolve boron trifluoride, the salt is commonly used as a convenient source of the chemical at the laboratory scale: [5]
LiBF4 is a byproduct in the industrial synthesis of diborane: [5] [6]
LiBF4 can also be synthesized from LiF and BF3 in an appropriate solvent that is resistant to fluorination by BF3 (e.g. HF, BrF3, or liquified SO2): [5]