TetraPEG Network Formation via a Michael Addition Reaction in an Ionic Liquid: Application to Polymer Gel Electrolyte for Electric Double-layer Capacitors

Polymer Gel Electrolyte Prepared by “Salting-In” Poly(ethylene glycol) into a Phosphonium-Based Ionic Liquid with a Lithium Salt

“…where k gel ′ is the apparent rate constant. 34,35 The experimental variation showed a good agreement with the fitting result, suggesting the assumption applied in the current TetraPEG gelation system was valid. The k gel ′ in the current LiTFSA/[P 2225 ][TFSA] system was 0.09 M −1 s −1 that was within the order of magnitude of values reported in other IL-based system.…”

“…The k gel ′ in the current LiTFSA/[P 2225 ][TFSA] system was 0.09 M −1 s −1 that was within the order of magnitude of values reported in other IL-based system. 34,35 The p (right axis in Figure 4b), which was calculated based on the relation p = [MA-S]/[-MA] ini , rapidly increased up to t = 1.0 × 10 4 s and reached a plateau near 4.5 × 10 4 s, resulting in a nearly ideal polymer network, p ∼ 95%. To obtain more insight into the gelation process, rheological measurements were also performed for the current IL electrolyte system, which is shown in Figure 5.…”

“…We found that the reaction time (t) at the intersection of the storage (G′) and loss (G″) moduli, corresponding to the gelation point (t gel ), was 4.2 × 10 2 s. Herein, note that the G′ and G″ profiles showed a twostep increase, which is largely different from those observed in neat ILs (without Li salt) with one-step increase. 34,35 This difference implies that Li ion strongly depends on the TetraPEG gelation mechanism in IL solutions. In speculation, solution; the p value of the sample gel was set to ∼95% according to the calculated p vs t curve (see Figure 4b, right axis).…”

“…34 Stretching measurements were performed for dumbbell-shaped TetraPEG ion gels (size of the rectangular portion, 2.0 × 12.0 × 2.0 mm 3 ) at a constant velocity of 60 mm min −1 using a mechanical testing apparatus (STB-1225S, A&D Company). Raman spectra of the TetraPEG ion gels were measured using a laser Raman spectrophotometer (NRS-3100, JASCO) with a 532.2 nm laser at 298 K. The ionic conductivity was measured by AC impedance spectroscopy using a frequency response analyzer (SI-1260, Solartron) in the temperature range from 278 to 338 K (i.e., 5,15,25,35,45,55, and 65 °C): the details are described in a previous report. 34 Linear sweep voltammetry (LSV) was performed using a Pt working electrode with Li foil (counter and reference electrodes) to investigate the electrochemical stability with an electrochemical measurement system (HZ-5000, Hokuto Denko): the details are described in a previous report.…”

Synthesis of gels by means of Michael addition reaction of multi‐functional acetoacetate and diacrylate compounds and their application to ionic conductive gels

“…We study the effect of the molecular structure of the joint and linker source monomers on the mechanical properties of the resultant gels. The PEG units have been used as cation carriers in electrolytes of polymer batteries 15–17 . In addition, the present polymer networks do not contain N atoms, which would sometimes inhibit transportation of ions.…”