Polymers ionic liquid gels

Terasawa N, Takeuchi I, Mukai K et al (2010) The effects of Li salts on the performance of a polymer actuator based on single-walled carbon nruiotube-ionic liquid gel. Polymer 51 3372-3376... 

Pandey, G. P., A. C. Rastogi, and C. R. Westgate. 2014. All-solid-state supercapacitors with poly(3,4-ethylenedioxythiophene)-coated carbon fiber paper electrodes and ionic liquid gel polymer electrolyte. Journal of Power Sources 245 857-865. 

The issues that remain to be addressed are the readability and stability of the device. The IPMC actuators are usually operated in wet conditions, while organic transistors degrade easily in moisture and/or oxygen. The straightforward approach toward suppressing such degradation is to employ more sophisticated encapsulation techniques. Alternately, the use of the ionic-liquid-gel based polymer actuator technology, which can be operated in ambient air, is an option. 

Fig. 9.8 (a) Temperature dependence of ionic conductivity of the ionic liquid gel polymer electrolyte film. Inset The corresponding log (a T ) vs 1/(T - To) plot, (b) Cyclic voltammetry curves of EDLC cells at different scan rates. On the graph, there is a picture of a transparent and free-standing gel polymer electrolyte film, (c) Variation in the capacitance values of the EDLC cells [110]... 

Liu L, Yang P, Li L, Cui Y, An M (2012) Application of bis(trifluoromethanesulfonyl)imide lithium-N-methyl-N-butylpiperidinium-bis(trifluoromethanesulfonyl)imide-poly(vinyUdene difluoride-co-hexafluoropropylene) ionic liquid gel polymer electrolytes in Li/LiFeP04 batteries at different temperatures. Electrochim Acta 85 49-56. doi 10.1016/j. electacta.2012.08.066... 

Guerfi A, Dontigny M, Kobayashi Y, Vijh A, Zaghib K (2009) Investigations on some electrochemical aspects of lithium-ion ionic liquid/gel polymer battery systems. J Solid State Electrochem 13(7) 1003-1014. doi 10.1007/sl0008-008-0697-x... 

Stepniak I (2014) Compatibility of poly(bisAEA4)-LiTFSI-MPPipTFSI ionic liquid gel polymer electrolyte with Li4Ti50i2 hthium ion battery anode. J Power Sources 247 112-116. doi 10.1016/j.jpowsour.2013.08.080... 

Pandey GP, Hashmi SA, Kumar Y (2010) Performance studies of activated charcoal based electrical double layer capacitors with ionic liquid gel polymer electrolytes. Energy Fuels 24(12) 6644-6652. doi 10.1021/efl010447... 

Ionic liquids have already been demonstrated to be effective membrane materials for gas separation when supported within a porous polymer support. However, supported ionic liquid membranes offer another versatile approach by which to perform two-phase catalysis. This technology combines some of the advantages of the ionic liquid as a catalyst solvent with the ruggedness of the ionic liquid-polymer gels. Transition metal complexes based on palladium or rhodium have been incorporated into gas-permeable polymer gels composed of [BMIM][PFg] and poly(vinyli-dene fluoride)-hexafluoropropylene copolymer and have been used to investigate the hydrogenation of propene [21]. 

Solid polymer and gel polymer electrolytes could be viewed as the special variation of the solution-type electrolyte. In the former, the solvents are polar macromolecules that dissolve salts, while, in the latter, only a small portion of high polymer is employed as the mechanical matrix, which is either soaked with or swollen by essentially the same liquid electrolytes. One exception exists molten salt (ionic liquid) electrolytes where no solvent is present and the dissociation of opposite ions is solely achieved by the thermal disintegration of the salt lattice (melting). Polymer electrolyte will be reviewed in section 8 ( Novel Electrolyte Systems ), although lithium ion technology based on gel polymer electrolytes has in fact entered the market and accounted for 4% of lithium ion cells manufactured in 2000. On the other hand, ionic liquid electrolytes will be omitted, due to both the limited literature concerning this topic and the fact that the application of ionic liquid electrolytes in lithium ion devices remains dubious. Since most of the ionic liquid systems are still in a supercooled state at ambient temperature, it is unlikely that the metastable liquid state could be maintained in an actual electrochemical device, wherein electrode materials would serve as effective nucleation sites for crystallization. 

To address the zinc dendrite problem in nickel-zinc cells, eVionyx claims to have developed a proprietary membrane system that is nonporous, has very high ionic conductivity, is of low cost, and can block zinc dendrite penetration even in high concentrations of KOH. The polymeric membrane has an ionic species contained in a solution phase thereof. The ionic species behaves like a liquid electrolyte, while at the same time the polymer-based solid gel membrane provides a smooth impenetrable surface that allows the exchange of ions for both discharging and charging of the cell. 

Figure 2.3-1 Substrate interactions with (I to r) solid-supported reagent, polymer gel supported reagent, task-specific ionic liquid.

Ogihara, W. et al., Ionic conductivity of polymer gels deriving from alkali metal ionic liquids and negatively charged polyelectrolytes, Electrochim. Acta, 49,1797,... 

However, radical polymerization of common vinyl monomers in situ in ionic liquids [16] produced new polymer-electrolytes called ion gels. These ion gels have completely compatible combinations of ionic liquids and the resulting network polymers. The ion gels can softly bend, and they showed fast ionic conductivity of 10 S cm at room temperature. 

Many approaches have been developed for the production of ionic liquid-polymer composite membranes. For example, Doyle et al. [165] prepared RTILs/PFSA composite membranes by swelling the Nafion with ionic liquids. When 1-butyl, 3-methyl imidazolium trifluoromethane sulfonate was used as the ionic liquid, the ionic conductivity ofthe composite membrane exceeded 0.1 S cm at 180 °C. A comparison between the ionic liquid-swollen membrane and the liquid itself indicated substantial proton mobility in these composites. Fuller et al. [166] prepared ionic liquid-polymer gel electrolytes by blending hydrophilic RTILs into a poly(vinylidene fiuoridej-hexafluoropropylene copolymer [PVdF(HFP)] matrix. The gel electrolytes prepared with an ionic liquid PVdF(HFP) mass ratio of 2 1 exhibited ionic conductivities >10 Scm at room temperature, and >10 Scm at 100 °C. When Noda and Watanabe [167] investigated the in situ polymerization of vinyl monomers in the RTILs, they produced suitable vinyl monomers that provided transparent, mechanically strong and highly conductive polymer electrolyte films. As an example, a 2-hydroxyethyl methacrylate network polymer in which BPBF4 was dissolved exhibited an ionic conductivity of 10 S cm at 30 °C. 

Hong SH, Kim TY, Suh KS et al (2010) Preptuation of single-walled ctubon nanotube (SWNT) gel composites using poly(ionic liquids). Colloid Polym Sci 288 1013-1018... 

Susan, M.A., Kaneko, T., Noda, A. and Watanabe, M. (2005) Ion gels prepared by in situ radical polymerization of vinyl monomers in an ionic liquid and their characterization as polymer electrolytes. /. Am. Chem. Soc., 127, 4976M983. 

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