Electrolytes ether-based

Dioxolane-l, 2-dimethoxyethane-Li2 B1()C11() exhibited chemical stability towards the components of a lithium-titanium disulfide cell and showed promise as an electrolyte in such cells [98], Among various systems composed of an ether-based solvent and a lithium salt, THF-LiAsF6 was the least reactive to lithium at elevated temperature and gave the best cycling efficiency [99, 100], Tetrahydrofu-ran-diethyl ether-LiAsF(i afforded lithium electrode cycling efficiency in excess of 98% [101],... 

The superiority of LiAsF6 in ether based solvents (2-Me-THF, THF, MeF) at lithium electrodes is an example of the formation of useful protecting films (As, Li2 As, Li (AsFv) allowing uniform lithium deposition [195], According to Aur-bach and co-workers, LiAsF6/2 - Me -THF is a highly suitable electrolyte for rechargeable lithium batteries. However, as 2-Me-THF is one of the least reactive sol-... 

The direct evidence on which our view of cation solvation in polymer electrolytes is based comes mainly from spectroscopic techniques. IR and Raman studies have been carried out on a variety of systems (see Chapter 5, Torell and Schantz, 1989 and Freeh, Manning, Teeters and Black, 1988). Low frequency vibrational modes, around 860-870 cm associated with the cation-ether oxygen interactions in PEG based systems have been observed they are absent in PEO itself... 

Like LiAsFe, LiBF4 is a salt based on an inorganic superacid anion and has moderate ion conductivity in nonaqueous solvents (Table 3). It was out of favor in the early days of lithium battery research because the ether-based electrolytes containing it were found to result in poor lithium cycling efficiencies, which decayed rapidly with cycle number. ° The reactivity of LiBF4 with lithium was suspected as discoloration occurred with time or heating. 

The cathode materials employed for the early lithium-based systems were 3.0 V class oxides or sulfides thus, the redox potential for the additive should be located in the neighborhood of 3.2—3.5 V. Accordingly, the first generation redox additive proposed by Abraham et al. was based on the iodine/ iodide couple, which could be oxidatively activated at the cathode surface at 3.20 V and then reduced at the lithium surface. " " " 2° For most of the ether-based solvents such as THF or DME that were used at the time, the oxidation potential of iodide or triiodide occurred below that of their major decompositions, while the high diffusion coefficients of both iodine and iodide in these electrolyte systems ( 3 x 10 cm s ) offered rapid kinetics to shuttle the overcharge current. Similarly, bromides were also proposed.Flowever, this class of halide-based additives were deemed impractical due to the volatility and reactivity of their oxidized forms (halogen). 

While Wright and co-workers were the first group of researchers to discover that the ether-based polymer poly (ethylene oxide) (PEG) was able to dissolve inorganic salts and exhibit ion conduction at room temperature, " it was the suggestion from Armand et al. that placed these novel materials at the center stage of lithium electrolyte research for more than a decade.The number of comprehensive reviews on this subject could serve as an indicator of the general enthusiasm for these materials during the period. ... 

K. Nakabayashi, T. Higashihara, M. Ueda, Polymer electrolyte membranes based on cross-linked highly sulfonated multiblock copoly(ether sulfone)s. Macromolecules 2010,43(13), 5756-5761. 

Nakabayashi K, Higashihara T, Ueda M. Polymer electrolyte membranes based on poly-(phenylene ether)s with pendant perfluoroalkyl sulfonic acids. Macromolecules 2011 44(6) 1603-9. 

R. Younesi, M. HahUn, M. Treskow, J. Scheers, P. Johansson, K. Edstrom, J. Phys. Chem. C 2012,116,18597-18604. Ether based electrolyte, LiB(CN)4 salt and binder degradation in the Li-02 battery studied by hard X-ray photoelectron spectroscopy (HAXPES). 

Morita, M. Kawasaki, T Yoshrmoto, N. Ishikawa, M., Nonflammable oiganic electrolyte solution based on perfluoro-ether solvent for lithium ion batteries. Electrochemistry 2003, 71, 1067-1069. 

S. A. Freunberger, Y. H. Chen, N. E. Drewett, L. J. Hardwick, F. Barde, P. G. Bruce, The Lithium-Oxygen Battery with Ether-Based Electrolytes, Angew. Chem., Int. Ed. 2011, 50, 8609-8613. 

Kato Y., Ishihara X, Uchimoto Y., Wakihara M. Charge-Transfer Reaction Rate of LiVLi Couple in Poly(ethylene glycol) Dimethyl Ether Based Electrolytes, J. Phys. Chem. B 2004, 108, 4794-4798. 

Meanwhile, independent of whether the solvent decomposition reaction proceeds via 02 , Li02, or another Li-air reactive species, it is now clear that a solvent that is resistant to attack by reduced O2 species must be discovered in order to achieve a practical Li-air cell with a longer cycle life. Besides the problems of solvent electrochemical stability, the electrochemical selectivity and chemical stability has to be resolved. Thus, regardless of whether ether-based electrolytes are completely inert towards the reduced O2 radical species, the search for more stable electrolyte will remains an active investigation area in Li-air in the near future. Since we wrote. 

Read, J., Ether-Based Electrolytes for the Lithium/Oxygen Oigeuiic Electrolyte Battery. J. Electrochem. Soc. 2006,755, A96-A100. 

Borodin O, Smith GD (2007) Molecular dynamics simulations of comb-branched poly (epoxide ether)-based polymer electrolytes. Macromolecules 40 1252-1258... 

Y. Chang, G.F. Brunello, J. Puller, M.L. Disabb-Miller, M.E. Hawley, Y.S. Kim, M.A. Hickner, S.S. Jang, C. Bae, Polymer electrolyte membranes based on poly(arylene ether sulfone) with pendant perfluorosulfonic acid, Polym. Chem. 4 (2) (2013) 272-281. 

X.B. Zhu, H.M. Zhang, Y.M. Liang, Y. Zhang, Q.T. Luo, C. Bi, B.L. Yi, Challenging reinforced composite polymer electrolyte membranes based on disulfonated poly(arylene ether sulfone)-impregnated expanded PIPE for fuel cell applications, J. Mater. Chem. 17 (4) (2007) 386-397. 

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