Ether-Based Solvents

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 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). 

One surprise in Arai s results is perhaps the anodic stability of the ether-based solvent MFE, which remained stable anodically at up to 4.2 V on the LiCo02 surface. Considering the numerous previous reports that the ether linkage is oxidatively decomposed near 4.0 V, " 5J8,93 might attribute this additional stability of MFE to the fluorination of the molecule. 

Delmau, L.H., Bonnesen, P.V., Moyer, B.A. 2004. A solution to stripping problems caused by organophilic anion impurities in crown-ether based solvent extraction systems A case study of cesium removal from radioactive wastes. Hydrometallurgy 72 (1-2) 9-19. 

Delmau, L. H., Bonnesen, P. V., and Moyer, B. A. A Solution to Stripping Problems Caused by Organophilic Anion Impurities in Crown-Ether Based Solvent Extraction Systems, A Case Study of Cesium Removal from Radioactive Wastes, Hydrometallurgy 72(1,2) (2004), 9-19. 

Table 5.1 Glycol ether based solvents (3). Glycol Ether Type...

Assary RS, Lu J, Du P et al (2012) The effect of oxygen crossover on the anode of a Li-02 battery using an ether-based solvent insights fiom expraimental and computational studies. ChemSusChem 6 51-55. doi 10.1002/csse.201200810... 

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