Ionic liquid‐based organic–inorganic hybrid electrolytes: Impact of in situ obtained and dispersed silica

Abstract

Organic–inorganic hybrid electrolytes based on PEO‐NaTFSI‐ionic liquid (HMIMTFSI)‐silica (in situ production via sol gel process) are being reported in this article. The variation in conductivity with ionic liquid (IL) addition has been explained on the basis of number of free TFSI anions evaluated using ATR‐IR data. The deconvolution of the IR spectra of these hybrid electrolytes has given evidence of ion‐pair formation which has been compared vis‐á‐vis the conductivity variation. The hybrid electrolyte with maximum conductivity comprises the highest number of free imide ions and has lowest glass transition temperature. FESEM has displayed a porous and layered surface morphology with dispersed silica nanoparticles. In addition, the optimized hybrid electrolyte has been compared with 5 wt% (limit of mechanical stability) ex situ silica added composite where the temperature cycling of conductivity has shown that the ex situ dispersed hybrid electrolytes do not retrace their conductivity path contrary to the in situ prepared hybrid electrolytes. This behavior has been explained to be due to the hindrance offered by the ex situ added silica in the recrystallization kinetics of PEO. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 207–218

Ionanofluid plasticized electrolyte with improved electrical and electrochemical properties for high‐performance lithium polymer battery

“…However, for 40INF‐PE, two distinct glass transition temperatures can be observed at T g1 = −54.7°C and T g2 = −44.3°C, respectively. This is similar to the earlier report observed for HMIM‐TFSI RTIL plasticized PEO‐LiTFSI electrolyte and, accordingly, it indicates that 40 wt% is the proximity of the miscibility limit of INF in PEO 39 . In this concern, it is important to mention that T g for 30IL‐PE electrolyte also shifts to a lower value (−47.9°C) [Figure S5(a)], but not as low as observed for 30INF‐PE.…”

“…XRD pattern of pure PEO depicts two characteristic crystalline peaks at 2θ ~19.3° and 23.6° on the background of a broad amorphous hump. These two peaks correspond to [120] and [112] plane of crystalline PEO 39,40 . Some small peaks at 2θ ~ 26.3°, 27°, 36.4°, and 40° are also observed in the diffraction profile, which clearly designates the semi‐crystalline characteristics of PEO.…”

“…This is similar to the earlier report observed for HMIM-TFSI RTIL plasticized PEO-LiTFSI electrolyte and, accordingly, it indicates that 40 wt% is the proximity of the miscibility limit of INF in PEO. 39 In this concern, it is important to mention that T g for 30IL-PE electrolyte also shifts to a lower value (−47.9 C) [ Figure S5(a)], but not as low as observed for 30INF-PE. A reduction in T g corresponds to easy chain movement, that is, faster segmental motion for PEO.…”

“…These two peaks correspond to [120] and [112] plane of crystalline PEO. 39,40 Some small peaks at 2θ 26.3 , 27 , 36.4 , and 40 are also observed in the diffraction profile, which clearly designates the semicrystalline characteristics of PEO. In PE, complexation of PEO with LiTFSI salt leads to a noticeable reduction in the intensity of all the distinctive peaks with a corresponding increase in the amorphous hump.…”

Gel-polymer electrolytes based on polyurethane ionomers for lithium power sources

“…[28][29][30] To increase the ionic conductivity, it was proposed to plasticize SPE with organic solutions of a lithium salt and ionic liquids. [31][32][33][34][35][36][37][38][39] Retention of lithium ions solutions by a polymer matrix leads to the formation of polymer gel electrolytes (GPE), 40 which simplify the technology of manufacturing various electrochemical devices with effective electrode-electrolyte contacts. [24][25][26][27][28] At this moment, polymer matrices based on polyethylene oxide (PEO), [41][42][43][44][45] polycarbonate (PC), 46,47 polyacrylonitrile (PAN), 48 poly(methyl methacrylate) (PMMA) 49,50 and polyvinylidene uoride (PVDF) 51 are well studied.…”