2 research outputs found
Solvate Structures and Computational/Spectroscopic Characterization of LiBF<sub>4</sub> Electrolytes
Crystal structures have been determined
for both LiBF<sub>4</sub> and HBF<sub>4</sub> solvates: (acetonitrile)<sub>2</sub>:LiBF<sub>4</sub>, (ethylene glycol diethyl ether)<sub>1</sub>:LiBF<sub>4</sub>, (diethylene glycol diethyl ether)<sub>1</sub>:LiBF<sub>4</sub>, (tetrahydrofuran)<sub>1</sub>:LiBF<sub>4</sub>, (methyl
methoxyacetate)<sub>1</sub>:LiBF<sub>4</sub>, (succinonitrile)<sub>1</sub>:LiBF<sub>4</sub>, (<i>N</i>,<i>N</i>,<i>N</i>ā²,<i>N</i>ā³,<i>N</i>ā³-pentamethyldiethylenetriamine)<sub>1</sub>:HBF<sub>4</sub>, (<i>N</i>,<i>N</i>,<i>N</i>ā²,<i>N</i>ā²-tetramethylethylenediamine)<sub>3/2</sub>:HBF<sub>4</sub>, and (phenanthroline)<sub>2</sub>:HBF<sub>4</sub>. These, as well as other known LiBF<sub>4</sub> solvate structures,
have been characterized by Raman vibrational spectroscopy to unambiguously
assign the anion Raman band positions to specific forms of BF<sub>4</sub><sup>ā</sup>Ā·Ā·Ā·Li<sup>+</sup> cation
coordination. In addition, complementary DFT calculations of BF<sub>4</sub><sup>ā</sup>Ā·Ā·Ā·Li<sup>+</sup> cation
complexes have provided additional insight into the challenges associated
with accurately interpreting the anion interactions from experimental
Raman spectra. This information provides a crucial tool for the characterization
of the ionic association interactions within electrolytes
Structural Interactions within Lithium Salt Solvates: Cyclic Carbonates and Esters
Only limited information is available
regarding the manner in which cyclic carbonate and ester solvents
coordinate Li<sup>+</sup> cations in electrolyte solutions for lithium
batteries. One approach to gleaning significant insight into these
interactions is to examine crystalline solvate structures. To this
end, eight new solvate structures are reported with ethylene carbonate,
Ī³-butyrolactone, and Ī³-valerolactone: (EC)<sub>3</sub>:LiClO<sub>4</sub>, (EC)<sub>2</sub>:LiClO<sub>4</sub>, (EC)<sub>2</sub>:LiBF<sub>4</sub>, (GBL)<sub>4</sub>:LiPF<sub>6</sub>, (GBL)<sub>1</sub>:LiClO<sub>4</sub>, (GVL)<sub>1</sub>:LiClO<sub>4</sub>, (GBL)<sub>1</sub>:LiBF<sub>4</sub>, and (GBL)<sub>1</sub>:LiCF<sub>3</sub>SO<sub>3</sub>. The crystal structure of (EC)<sub>1</sub>:LiCF<sub>3</sub>SO<sub>3</sub> is also re-reported for comparison. These structures
enable the factors that govern the manner in which the ions are coordinated
and the ion/solvent packingīøin the solid-stateīøto be
scrutinized in detail