Highly Conductive Siloxane Polymers

Hooper, Richard; Lyons, Leslie J.; Mapes, Marie K.; Schumacher, Douglas; Moline, David A.; West, Robert

doi:10.1021/ma0018446

Cited by 134 publications

(126 citation statements)

References 16 publications

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“…However the picture is changed at more high content of the salts. In accordance with the conception expressed in [18] at increasing of the concentration of salts with relatively big anions the probability of creation of so called pairs of the ions increases and consequently the current density decreases more intensively than in case of little anions. It is interesting the behaviour of the conductivity of PE -P 1 S 2 with 20 wt.…”

Section: Resultssupporting

confidence: 76%

“…Oligo(ethylene glycol)-substituted polysiloxanes as ionically conductive polymer hosts have been previously investigated by Smid [10,11], Shriver [12][13][14], Acosta [15] and West and co-workers [16,17]. The more recent synthesis and conductivity studies of a bis-substituted polysiloxane with pendant oligo-(ethylene glycol) chains have been reported by Hooper et al [18]. A six-oxygen sidechain polymer host when doped with lithium bis(trifluoromethylsulfonyl)imide (LiTFSl) showed the highest room temperature conductivity (4.0 x 10 -4 S cm -1 ) yet observed for a polymer electrolyte.…”

Section: Introductionmentioning

confidence: 99%

“…The polysiloxanes with very low glass transition temperatures, T g = -123 0 C for poly(dimethylsiloxane) and extremely high free volumes and thermo-oxidative stability [8,9] are expected to be good hosts for Li + transport when polar units are introduced onto the polymer backbone. Oligo(ethylene glycol)-substituted polysiloxanes as ionically conductive polymer hosts have been previously investigated by Smid [10,11], Shriver [12][13][14], Acosta [15] and West and co-workers [16,17].…”

Section: Introductionmentioning

confidence: 99%

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Synthesis of cross-linked comb-type polysiloxane for polymer electrolyte membranes

et al. 2012

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Hydrosilylation reaction of 2.4.6.8-tetrahydro-2.4.6.8-tetramethylcyclotetrasiloxane with allyl acetoacetate and vinyltriethoxysilane at 1:3:1 ratio of initial compounds in the presence of Karstedt's catalyst (Pt 2 [(VinSiMe 2 ) 2 O] 3 ), platinum hydrochloric acid (0.1 M solution in THF) and platinum on the carbon have been studied and D 4 R,R' type methylorganocyclotetrasiloxane has been obtained. Ring-opening co-polymerization reactions of methylorganocyclotetrasiloxane and hexamethyldisiloxane, in the presence of catalytic amount of powder-like potassium hydroxide, have been carried out and linear methylsiloxane oligomer with regular arrangement of propyl acetoacetate and triethoxysilane groups in the side chain has been obtained. The synthesized methylorganocyclotetrasiloxane and oligomers were studied by FTIR, 1 H, 13 C, 29 Si NMR spectroscopy. Comb-type oligomers were characterized by gel-permeation chromatography, wide-angle X-ray and differential scanning calorimetric methods. Via sol-gel processes of doped with lithium trifluoromethylsulfonate (triflate) or lithium bis-(trifluoromethylsulfonyl)imide oligomer systems solid polymer electrolyte membranes have been obtained. The dependence of ionic conductivity as a function of temperature and salt concentration has been studied. The electrical conductivity of these materials at room temperature belongs to the range of 7x10 -8 to 4x10 -6 S cm -1 and depends on the structures of grafted anion receptors and the polymer backbones.

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Section: Resultssupporting

confidence: 76%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Synthesis of cross-linked comb-type polysiloxane for polymer electrolyte membranes

et al. 2012

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“…Among the novel polymer materials investigated, polymers with an inorganic backbone, in particular polysiloxanes [12][13][14][15] and polyphosphazenes [16,17], are considered as very promising. The primary advantages of these inorganic polymers are their highly flexible backbone with enhanced segmental mobility together with a high chemical as well as thermal stability.…”

Section: Introductionmentioning

confidence: 99%

Transport Mechanisms of Ions in Graft-Copolymer Based Salt-in-Polymer Electrolytes

Kunze

Schulz

Wiemhöfer

et al. 2010

Zeitschrift Für Physikalische Chemie

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Polymer Electrolyte / Nuclear Magnetic Resonance / Spin Relaxation / Pulsed Field Gradient NMR / ConductivitySalt-in-polymer electrolytes based on graft copolymers with oligoether side chains and added LiCF 3 SO 3 (LiTf) are investigated concerning the transport and dynamics of the ionic species with respect to applications as Li ion conductors. Polymer architectures are based on polysiloxane or polyphosphazene backbones with one or two side chains per monomer, respectively. NMR methods provide information about molecular dynamics on different length scales: The mechanisms governing local dynamics and long range mass transport are studied on the basis of temperature dependent spin-lattice relaxation rates and pulsed field gradient diffusion measurements for 7 Li, 19 F and 1 H, respectively. The correlation times characterizing local ion dynamics reflect the complexation of the cations by the oligoether side chains of the polymer.7 Li and 19 F diffusion coefficients and their activation energies are rather similar, suggesting the formation of ion pairs and clusters with similar activation barriers for cation and/or anion long-range transport. Activation energies of local reorientations are generally significantly smaller than activation energies of long range diffusion. Long range transport is affected by (1) the coupling of conformational side chain reorientations to the cation movement, and (2) the correlated diffusion of cations and anions within ion pairs. Ion pairs and their dissociation play a major role in controlling the resulting conductivity of the material. Guidelines for material optimization in terms of a maximized conductivity can thus be derived by identifying a compromise between high ionic mobility and good Li complexation by the coordinating side chains.

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“…Scheme 8 compiles three further substitution concepts which have been investigated within the polysiloxane class of polymer electrolytes. In most cases, maximum conductivities around 2 × 10 −4 S/cm were reported [51][52][53][54].…”

Section: Polysiloxane Based Electrolytesmentioning

confidence: 97%

Salt-in-Polymer Electrolytes for Lithium Ion Batteries Based on Organo-Functionalized Polyphosphazenes and Polysiloxanes

Burjanadze

Karatas

Kaskhedikar

et al. 2010

Zeitschrift Für Physikalische Chemie

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An overview is given on polymer electrolytes based on organo-functionalized polyphosphazenes and polysiloxanes. Chemical and electrochemical properties are discussed with respect to the synthesis, the choice of side groups and the goal of obtaining membranes and thin films that combine high ionic conductivity and mechanical stability. Electrochemical stability, concentration polarization and the role of transference numbers are discussed with respect to possible applications in lithium batteries. It is shown that the ionic conductivities of salt-in-polymer membranes without additives and plasticizers are limited to maximum conductivities around 10 −4 S/cm. Nevertheless, a straightforward strategy based on additives can increase the conductivities to at least 10 −3 S/cm and maybe further. In this context, the future role of polymers for safe, alternative electrolytes in lithium batteries will benefit from concepts based on polymeric gels, composites and hybrid materials. Presently developed polymer electrolytes with oligoether sidechains are electrochemically stable in the potential range 0-4.5 V (vs. Li/Li + reference).

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Highly Conductive Siloxane Polymers

Cited by 134 publications

References 16 publications

Synthesis of cross-linked comb-type polysiloxane for polymer electrolyte membranes

Synthesis of cross-linked comb-type polysiloxane for polymer electrolyte membranes

Transport Mechanisms of Ions in Graft-Copolymer Based Salt-in-Polymer Electrolytes

Salt-in-Polymer Electrolytes for Lithium Ion Batteries Based on Organo-Functionalized Polyphosphazenes and Polysiloxanes

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