Electrolyte Formulation and Cell Performance

The oxidation process of electrolyte solutions is complicated. Although electrolyte solutes (lithium salts) are involved, solvents are believed to be the major component responsible for the catalytic decomposition on the cathodes [147, 166]. Angell s 

Because these sulfone derivatives have no ability to form an effective SEI, 2 wt% of vinylene carbonate (VC) was added in 1 mol dm LiPFe in EMES or MEMS for graphite/LiCoOa full cells [174]. Imol dm LiPFg in EMES+2 wt% VC showed a capacity drop, when the rate was raised to 0.50 mA cm (C/4.6), whereas 1 mol dm LiPFg in MEMS + 2 wt% VC exhibited almost the same performance as the reference electrolyte, 1 mol dm LiPFg in EC-DMC (50-50 vol.%), at 0.46 mA cm (C/5). These results indicated that more flnid versions of the sulfone-based electrolytes are necessary. 

To circnmvent the low separator wettability and low electrolytic conductivity of single-solvent systems based on sulfone solvents as mentioned before, blending with a low-viscosity solvent such as EMC is a practical approach [170]. Based on this guideline, 1 mol dm LiBF4 in TMS-ethyl acetate (50-50 yo. %)+2 vol.% VC was tested for Li/LiNii/2Mn3/204 cells. 

Electrolytes nonaqueous, In Encyclopedia of electrochemical power sources-, Garche, J. Dyer, C. Moseley, P. Ogumi, Z. Rand, D. Scrosati, B., Eds. Elsevier Amsterdam, Netherlands, 2009 Vol. 5 71-84. 

Liquid-solid phase diagrams of ternary and quaternary organic carbonates, J. Electrochem. Soc. 2004, i5i, A731-A738. 

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