Advanced Salts—Imides, Methides, and Phosphorylimides

Similarly, the TFSI anion can be viewed as the SO3CF3 anion with a =NS02Cp3 group replacing an =0  

Lithium salts with asymmetric anions may also be of interest as these tend to be more soluble and form solvates with a lower than for salts with symmetric anions. Examples include lithium (fluorosulfonyl)(trifiuoromethanesulfonyl)imide (LiFTI or LiETA) (i.e., LiN(S02F)(S02CF3)) (Fig. 1.21c) [263-265, 336] and lithium (fiuorosulfonyl)(nonafluorobutanesulfonyl)imide (LiFNFSI) (i.e., LiN(S02F) 

Lithium tris(perfluoroaIkanesulfonyl)methide salts have also received some attention for battery electrolytes, especially the salt with the C(S02CF3)3 anion (TriTFSM ) (Figs. 1.22J and 1.23b). The experimental gas-phase acidity values 

N(P0(C2F5)2)2- C—gray, N—blue, O—red, F—light green, P—orange) 

In 1995, Barthel and Gores reported a new class of inexpensive and chemically, elec-trochanically, and thermally stable salts based upon boron chelate complex anions with aromatic or aliphatic diols or carboxylic acids. The first such salt reported was lithium bis(l,2-benzenediolato(2-)-0,0 )borate (LiBBE) (Fig. 1.26a) [372]. The acid with this anion was originally reported in 1949 by Schafer [388]. The LiBBB salt has a high solubility in aprotic solvents ( 1 M), but the oxidative stability is relatively low. A number of other nonfluorinated lithium salts with benzenediol nonfluorinated 

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