TY - JOUR
T1 - New boron compounds as additives for lithium polymer electrolytes
AU - Zygadło-Monikowska, E.
AU - Florjańczyk, Z.
AU - Tomaszewska, A.
AU - Pawlicka, M.
AU - Langwald, N.
AU - Kovarsky, R.
AU - Mazor, H.
AU - Golodnitsky, D.
AU - Peled, E.
N1 - Funding Information:
This work was supported in part by the Polish Ministry of Science and Higher Education (3T08E01528; N205080033) and in part by the Air Force Office of Scientific Research, Air Force Command, USAF, under grant number FA8655-05-1-3014.
PY - 2007/12/31
Y1 - 2007/12/31
N2 - A new class of difluoroalkoxyborane compounds ([RnOBF2]2) containing oligooxyethylene groups of various molecular weight in the form of a methyl monoether (Rn = CH3(OCH2CH2)n, n = 1, 2, 3 and 7) has been obtained in the reaction of BF3 etherate with appropriate glycols. 1H, 11B and 19F NMR spectral analysis of the derivatives obtained was carried out and the properties as Lewis acids of these derivatives have been compared with that of corresponding trialkoxyboranes and boron trifluoride in reaction with pyridine. The strength of the interaction of [R2OBF2]2 with the differing in "hardness" anions of various lithium salts has been analyzed on the basis of NMR spectra. The [RnOBF2]2 obtained were used as additives for polymer electrolytes containing PEO as polymer matrix and various lithium salts at an equimolar ratio of the boron compound to salt. The highest ionic conductivities, in the order 10-5 to 10-4 S cm-1 at 20-70 °C, were achieved for systems containing LiI and LiN(CF3SO2)2. The lithium transference number (t+) values, determined by the electrochemical method by steady-state technique for LiF and LiCF3SO3 are in the 0.6-0.8 range.
AB - A new class of difluoroalkoxyborane compounds ([RnOBF2]2) containing oligooxyethylene groups of various molecular weight in the form of a methyl monoether (Rn = CH3(OCH2CH2)n, n = 1, 2, 3 and 7) has been obtained in the reaction of BF3 etherate with appropriate glycols. 1H, 11B and 19F NMR spectral analysis of the derivatives obtained was carried out and the properties as Lewis acids of these derivatives have been compared with that of corresponding trialkoxyboranes and boron trifluoride in reaction with pyridine. The strength of the interaction of [R2OBF2]2 with the differing in "hardness" anions of various lithium salts has been analyzed on the basis of NMR spectra. The [RnOBF2]2 obtained were used as additives for polymer electrolytes containing PEO as polymer matrix and various lithium salts at an equimolar ratio of the boron compound to salt. The highest ionic conductivities, in the order 10-5 to 10-4 S cm-1 at 20-70 °C, were achieved for systems containing LiI and LiN(CF3SO2)2. The lithium transference number (t+) values, determined by the electrochemical method by steady-state technique for LiF and LiCF3SO3 are in the 0.6-0.8 range.
KW - Boron derivatives
KW - Ionic conductivity
KW - Lewis acid properties
KW - Lithium polymer electrolytes
KW - Lithium transference number
UR - http://www.scopus.com/inward/record.url?scp=35548953076&partnerID=8YFLogxK
U2 - 10.1016/j.electacta.2007.02.046
DO - 10.1016/j.electacta.2007.02.046
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AN - SCOPUS:35548953076
VL - 53
SP - 1481
EP - 1489
JO - Electrochimica Acta
JF - Electrochimica Acta
SN - 0013-4686
IS - 4
ER -