Structural Aspect on Li Ion Solvation in Room-Temperature Ionic Liquids

Highly efficient mixed Li+ transport in ion gel polycationic electrolytes

“…To understand the effect of IMMA on the diffusivity of a neutral species, a second Other authors [15,16] have suggested the contribution of an anion exchange mechanism to the Li + transport in specific electrolytes containing FSI. Similitudes are seen between the FSI and TFSI FTIR spectra in those electrolytes, [9,16] and the spectra of the electrolytes described in this work, which appear in Figure 4. In Figure 4a the FTIR spectra of the υ(S-N) region of FSI and TFSI in PEGMA-PEGMA/Li, COPO-COPO/Li and PIMMA-PIMMA/Li appear.…”

“…[7,8] Particularly interesting for electrochemical applications are RTILs containing bis(fluorosulfonyl)imide anion (FSI), because of its low viscosity, and because it has been demonstrated that the viscosity increase arising from the incorporation of a Li salt to an ionic liquid is much lower when the anion is FSI. [9] To date, the highest reported conductivity in a polymer gel electrolyte with RTIL (Nmethyl-N-propylpyrrolidinium bis(fluorosulfonyl)imide, PMPFSI) has been 1.6 mS cm −1 at 20 ºC [10], of which only a small part is actually Li ion conductivity. As Li + has a characteristic large solvation shell [11] DLi is smaller than its counteranions, [12,13] most frequently FSI or bis(trifluoromethane)sulfonimide (TFSI), and hence the contribution of Li to the overall conductivity is small.…”

Ionic Liquid-Based Thermoplastic Solid Electrolytes Processed by Solvent-Free Procedures

“…For binary mixtures of RTILs/LiTFSI, η increases dramatically with respect to pure RTILs, especially for RTILs with TFSI anions, following the η order EMIFSI << PMPFSI << EMITFSI << PMPTFSI. This is expected as FSI is known to lead to much lower η increases upon adding Li + than TFSI [ 21 ]. The mixture PMPTFSI/LiTFSI, which has a melting peak at about 7 °C, becomes too viscous to be measured (under the conditions used in this work) below 25 °C.…”