Ionic conductivity of polyether-polyurethane networks containing alkali metal salts. An analysis of the concentration effect

Killis, A.; Nest, J.F. Le; Gandini, Alessandro; Cheradame, Hervé

doi:10.1021/ma00131a012

Cited by 46 publications

(11 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The two peaks could be associated with a salt‐aggregated phase and a salt‐dissolved phase. Observations consistent with the formation of salt‐rich phases as the salt concentration was increased were also made for poly(propylene oxide) (PPO)/LiClO 4 and amorphous PEO1000/LiClO 4 complexes 23–25. For the organic NPEOs, the intensity of the tan δ peak at lower temperatures increased with a rising salt concentration.…”

Section: Resultssupporting

confidence: 59%

Thermal and thermomechanical properties of poly(ethylene oxide) networks produced with silica and organic crosslinking agents

Kweon¹,

Noh²

2003

J. Appl. Polym. Sci.

View full text Add to dashboard Cite

ABSTRACT:The thermal and thermomechanical properties of two series of poly(ethylene oxide) networks (NPEOs) were investigated as a function of the chain length between crosslink sites (M c ) and the concentration of LiClO 4 (C L ) in the NPEOs. The two series of networks were produced with silica and organic crosslinking agents and, therefore, had crosslink sites of different natures: one was an inorganic silicate network (silica NPEO), and the other was an organic polar group (organic NPEO). The crosslink sites in both series of networks were commonly covalently bonded to the poly(ethylene oxide) (PEO) phase through a urethane group in the NPEOs. The glass-transition temperatures (T g 's) of the PEO phases in the NPEOs, according to differential scanning calorimetry, increased with a decrease in M c and were higher in the silica NPEOs than in the organic NPEOs under the same M c conditions. The difference in T g between the two series of networks with the same M c values increased with decreasing M c . These results suggested that the interaction of crosslink sites with the PEO phase was stronger in the silica NPEOs than in the organic NPEOs. The addition of LiClO 4 to the NPEOs resulted in T g of the PEO phase in the NPEOs being elevated and increased according to the increase in C L . The increase of T g of the PEO phase according to the increase of C L in the NPEOs was retarded or saturated at high values of C L , and this indicated that the limit of solubility of the salt in the polymer was attained. The retardation or saturation of the increase of T g was also observed in dynamic mechanical analyses. The curves of the loss factor tan ␦ and temperatures from the dynamic mechanical analyses for the NPEOs with high values of C L showed shoulders or double peaks indicating the existence of the second phase in the polymer networks. In the curves of tan ␦ for salt-complexed NPEOs with high values of C L , silica NPEOs showed a shoulder of low intensity, but organic NPEOs showed a distinguished second peak becoming stronger with increasing C L . The results of the T g behavior and tan ␦ curves suggested that the salt solubility in the NPEOs was limited and that the salt solubility of PEO in the silica NPEOs was higher than that in the organic NPEOs.

show abstract

Section: Resultssupporting

confidence: 59%

Thermal and thermomechanical properties of poly(ethylene oxide) networks produced with silica and organic crosslinking agents

Kweon¹,

Noh²

2003

J. Appl. Polym. Sci.

View full text Add to dashboard Cite

show abstract

“…In simple electrolytes, one expects conductivity to increase linearly with salt concentration due to the increase in charge carrier concentration. In polymer electrolytes, ion transport is closely coupled to segmental relaxation of polymers, 61,67,68 which slows down with added salt due to associations between ions and the polymer segments. The trade-off between these two effects results in a conductivity maximum (e.g., Figure 4).…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

Optimizing Ion Transport in Polyether-Based Electrolytes for Lithium Batteries

et al. 2018

View full text Add to dashboard Cite

ABSTRACT:We report on the synthesis of poly(diethylene oxidealt-oxymethylene), P(2EO-MO), via cationic ring-opening polymerization of the cyclic ether monomer, 1,3,6-trioxocane. We use a combined experimental and computational approach to study ion transport in electrolytes comprising mixtures of P(2EO-MO) and lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) salt. Mixtures of poly(ethylene oxide) (PEO) and LiTFSI are used as a baseline. The maximum ionic conductivities, σ, of P(2EO-MO) and PEO electrolytes at 90°C are 1.1 × 10 −3 and 1.5 × 10 −3 S/cm, respectively. This difference is attributed to the T g of P(2EO-MO)/ LiTFSI (−12°C), which is significantly higher than that of PEO/LiTFSI (−44°C) at the same salt concentration. Self-diffusion coefficients measured using pulsed-field gradient NMR (PFG-NMR) show that both Li + and TFSI − ions diffuse more rapidly in PEO than in P(2EO-MO). However, the NMR-based cation transference number in P(2EO-MO) (0.36) is approximately twice that in PEO (0.19). The transference number measured by the steady-state current technique, t +,ss , in P(2EO-MO) (0.20) is higher than in PEO (0.08) by a similar factor. We find that the product σt +,ss is greater in P(2-EO-MO) electrolytes; thus, P(2EO-MO) is expected to sustain higher steady-state currents under dc polarization, making it a more efficacious electrolyte for battery applications. Molecular-level insight into the factors that govern ion transport in our electrolytes was obtained using MD simulations. These simulations show that the solvation structures around Li + are similar in both polymers. The same is true for TFSI − . However, the density of Li + solvation sites in P(2EO-MO) is double that in PEO. We posit that this is responsible for the observed differences in the experimentally determined transport properties of P(2EO-MO) and PEO electrolytes.

show abstract

“…It has already been ~h o~n~~~~,~~~~~~~ that the transport of ions across polyether-based networks 12 10.5 48 240 16 10 .4 51 248 23 10.1 50 265…”

Section: Ionic Conductivitymentioning

confidence: 99%

Crosslinked polyethers as media for ionic conduction

1988

Self Cite

View full text Add to dashboard Cite

A broad outline is given of a comprehensive investigation dealing with solid polymeric electrolytes containing ionic species. These materials are based on various types of polyethers (homopolymers, block and graft copolymers) crosslinked via urethane chemistry and either filled with a salt or transformed into ionomers with the anions attached to the chains. The properties studied were specific volume, swelling, glass transition temperature, viscoelasticity, ionic conductivity, transport numbers, magnetic relaxation of nuclei from both the polymer chains and the ions, and redox stability. Mechanisms and models are proposed to explain chain partitioning by cations and the mode of ionic transport. An all‐solid‐state battery was prepared with one of these materials to prove its good performance.

show abstract

Ionic conductivity of polyether-polyurethane networks containing alkali metal salts. An analysis of the concentration effect

Cited by 46 publications

References 1 publication

Thermal and thermomechanical properties of poly(ethylene oxide) networks produced with silica and organic crosslinking agents

Thermal and thermomechanical properties of poly(ethylene oxide) networks produced with silica and organic crosslinking agents

Optimizing Ion Transport in Polyether-Based Electrolytes for Lithium Batteries

Crosslinked polyethers as media for ionic conduction

Contact Info

Product

Resources

About