Preparation and properties of stat-copoly-(oxyethylene-oxypropylene)-block-poly (oxyethylene): 1. Use of crown ether in the anionic copolymerization of propylene oxide and ethylene oxide

Deng, Yulin; Ding, Jifeng; Yu, Ga-Er; Mobbs, Richard H.; Heatley, Frank; Price, Colin; Booth, Colin

doi:10.1016/0032-3861(92)90500-v

Cited by 17 publications

(14 citation statements)

References 7 publications

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“…Significant theoretical evidence suggests that ion transport in polymers is intrinsically coupled to polymer motion. − In particular, numerous theoretical studies of ion transport in PEO-based SPEs have shown that lithium cations are typically coordinated by 4–7 oxygen atoms (from one or two independent chains) and diffuse via three principal mechanisms: interchain hopping, intrachain hopping, and codiffusion with short polymer chains (<10 000 g/mol). Efforts to improve lithium-ion conductivity in PEO-based polymers have thus mainly focused on disrupting polymer crystallinity and lowering the glass-transition temperature T g , such as through the use of plasticizing additives, , cross-linked, comb, or graft polymer architectures, − incorporation of comonomers into the PEO backbone, − and polymer blends. , Despite these efforts, ionic conductivities in state-of-the-art, PEO-based SPEs remain limited at ambient temperatures …”

Section: Introductionmentioning

confidence: 99%

Systematic Computational and Experimental Investigation of Lithium-Ion Transport Mechanisms in Polyester-Based Polymer Electrolytes

et al. 2015

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Understanding the mechanisms of lithium-ion transport in polymers is crucial for the design of polymer electrolytes. We combine modular synthesis, electrochemical characterization, and molecular simulation to investigate lithium-ion transport in a new family of polyester-based polymers and in poly(ethylene oxide) (PEO). Theoretical predictions of glass-transition temperatures and ionic conductivities in the polymers agree well with experimental measurements. Interestingly, both the experiments and simulations indicate that the ionic conductivity of PEO, relative to the polyesters, is far higher than would be expected from its relative glass-transition temperature. The simulations reveal that diffusion of the lithium cations in the polyesters proceeds via a different mechanism than in PEO, and analysis of the distribution of available cation solvation sites in the various polymers provides a novel and intuitive way to explain the experimentally observed ionic conductivities. This work provides a platform for the evaluation and prediction of ionic conductivities in polymer electrolyte materials.

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Section: Introductionmentioning

confidence: 99%

Systematic Computational and Experimental Investigation of Lithium-Ion Transport Mechanisms in Polyester-Based Polymer Electrolytes

et al. 2015

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“…Rechargeable lithium-ion batteries are important for many technological applications . Since the discovery that polyethers like poly(ethylene oxide) (PEO) provide an ion-conducting medium, , there has been interest in developing solid polymeric electrolytes as a replacement for liquid electrolytes for safe, stable, and cost-effective batteries. , However, the ionic conductivities of such materials remain insufficient for many practical applications, despite research focus on both the synthesis of novel polymers − and additives. , Indeed, the most studied and widely employed polymer electrolytes continue to be based on PEO. − The design of more conductive polymer electrolytes requires both a better understanding of ion-transport mechanisms in polymers and the development of tools for screening candidate polymers prior to synthesis and characterization.…”

Section: Introductionmentioning

confidence: 99%

Chemically Specific Dynamic Bond Percolation Model for Ion Transport in Polymer Electrolytes

et al. 2015

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We introduce a coarse-grained approach for characterizing the long-timescale dynamics of ion diffusion in general polymer electrolytes using input from short molecular dynamics trajectories. The approach includes aspects of the dynamic bond percolation model [J. Chem. Phys. 1983, 79, 3133−3142] by treating ion diffusion in terms of hopping transitions on a fluctuating lattice. We extend this well-known approach by using short (i.e., 10 ns) molecular dynamics (MD) trajectories to predict the distribution of ion solvation sites that comprise the lattice and to predict the rate of hopping among the lattice sites. This yields a chemically specific dynamic bond percolation (CS-DBP) model that enables the description of long-timescale ion diffusion in polymer electrolytes at a computational cost that makes feasible the screening of candidate materials. We employ the new model to characterize lithium-ion diffusion properties in six polyethers that differ by oxygen content and backbone stiffness: poly(trimethylene oxide), poly(ethylene oxide-alt-trimethylene oxide), poly(ethylene oxide), poly(propylene oxide), poly(ethylene oxide-alt-methylene oxide), and poly(methylene oxide). Good agreement is observed between the predictions of the CS-DBP model and long-timescale atomistic MD simulations, thus providing validation of the model. Among the most striking results from this analysis is the unexpectedly good lithium-ion diffusivity of poly(trimethylene oxide-alt-ethylene oxide) by comparison to poly(ethylene oxide), which is widely used. Additionally, the model straightforwardly reveals a range of polymer features that lead to low lithium-ion diffusivity, including the competing effects of the density of solvation sites and polymer stiffness. These results illustrate the potential of the CS-DBP model to screen polymer electrolytes on the basis of ion diffusivity and to identify important design criteria.

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“…With increasing the length of the alkyl side chain R, PAOs such as poly(butylene oxide) (PBO), become fully amorphous and hydrophobic. The preparation of model block copolymers containing higher alkylene oxides beyond PEO is, however, rather challenging [24][25][26][27][28][29][30] due to the occurrence of chain transfer reactions during anionic polymerization. As a result, relatively few publications [31][32][33][34][35][36] have examined the morphological behavior of other PAO-containing block copolymers.…”

Section: Introductionmentioning

confidence: 99%

Phase behavior of polyisoprene-poly(butylene oxide) and poly(ethylene-alt-propylene)-poly(butylene oxide) block copolymers

2010

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Preparation and properties of stat-copoly-(oxyethylene-oxypropylene)-block-poly (oxyethylene): 1. Use of crown ether in the anionic copolymerization of propylene oxide and ethylene oxide

Cited by 17 publications

References 7 publications

Systematic Computational and Experimental Investigation of Lithium-Ion Transport Mechanisms in Polyester-Based Polymer Electrolytes

Systematic Computational and Experimental Investigation of Lithium-Ion Transport Mechanisms in Polyester-Based Polymer Electrolytes

Chemically Specific Dynamic Bond Percolation Model for Ion Transport in Polymer Electrolytes

Phase behavior of polyisoprene-poly(butylene oxide) and poly(ethylene-alt-propylene)-poly(butylene oxide) block copolymers

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