Polyethylene glycol-functionalized polyoctahedral silsesquioxanes as H+-conducting electrolytes

Sun, Chengjun; Ritchie, Jason E.

doi:10.1007/s10008-014-2409-z

Cited by 5 publications

(8 citation statements)

References 27 publications

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“…The semi-circle at high frequency is corresponding to a parallel combination of charge-transfer resistance and the double-layer capacitance (C dl ), which ascribed the charge-transfer of lithium ions on the surface of spinel oxide and electrode-electrolyte interface reaction process, is mainly controlled by chargetransfer process. [39] The straight line at lower frequency corresponds to Warburg impedance (Z W ), which caused by the solid-state diffusion of Li + in the electrode materials. [40] At high frequency the Warburg impedance is small since diffusion of Li + on the surface of the electrode which don't move very far.…”

Section: Electrochemical Propertiesmentioning

confidence: 99%

Electrospun Nd³⁺‐Doped LiMn₂O₄ Nanofibers as High‐Performance Cathode Material for Li‐Ion Capacitors

et al. 2017

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Electrospun high‐voltage spinel‐typeLiNd0.01Mn1.99O4 nanofibers (LNdMO NFs) were successfully prepared through the electrospinning technique. The thermal behavior of the electrospun precursor fibrous mat was assessed by thermogravimetric/differential thermal analysis. The crystallite structure and phase purity of Nd3+‐doped LiMn2O4 was confirmed by X‐ray diffraction studies. The chemical structure of the electrospun LNdMO NFs was characterized by Raman spectroscopy studies. The morphology of the nanofibers was examined by using field‐emission scanning electron microscopy. A Li‐ion capacitor (LIC) coin cell was fabricated by using high‐voltage insertion LNdMO NFs as the cathode and black pearl carbon as the anode with electrospun PVdF membrane containing 1 M LiNO3 as the separator and electrolyte. The electrochemical performance of the assembled LIC coin cell was characterized by using cyclic voltammetry, galvanostatic charge−discharge and electrochemical impedance spectroscopy. The LIC was capable of operating over wide potential window of 1.6 V with excellent capacitance retention of 86 % even after 2500 continuous galvanostatic charge−discharge cycles at a constant current density of 1 A g−1. Furthermore, LIC delivered an energy density of 17 Wh kg−1 and a power density of 397 W kg−1. Moreover, these results show that Nd3+‐doped LiMn2O4 NFs can be considered a promising electroactive cathode material for LICs.

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Section: Electrochemical Propertiesmentioning

confidence: 99%

Electrospun Nd³⁺‐Doped LiMn₂O₄ Nanofibers as High‐Performance Cathode Material for Li‐Ion Capacitors

et al. 2017

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“…Synthesis of MePEG 7 SO 3 H Acid (MePEG 7 (CH 2 ) 3 SO 3 H) was prepared as previously described. ,,− ,, …”

Section: Methodsmentioning

confidence: 99%

“…Siloxanes are easy to functionalize, and are chemically and mechanically stable, due to their chemical similarities to silica. − Both PEG and PPG can be coupled to siloxanes by hydrosilylation reactions to form the inorganic/organic hybrid. ,− Siloxane polymers are easily made from the acid catalyzed, sol–gel condensation of chlorosilanes or alkoxysilanes. Polymers formed by this condensation can exhibit the advantages of both the organic and inorganic portions, making them useful as polymer electrolytes.…”

Section: Introductionmentioning

confidence: 99%

Volume Fraction of Ether Is a Significant Factor in Controlling Conductivity in Proton Conducting Polyether Based Polymer Sol–Gel Electrolytes

2014

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We have synthesized several copolymers of methyl polyethylene glycol siloxane (MePEG7SiO3)m and methyl polypropylene glycol siloxane (MePPGnSiO3)m as hydrogen ion (H(+)) conducting polymer electrolytes. These copolymers were prepared by a sol-gel polymerization of mixtures of the MePEG and MePPG monomers. We synthesized these H(+) conducting polymer electrolytes in order to study the relationship between observed ionic conductivity and structural properties such as viscosity, fractional free volume, and volume fraction of ether. We found that viscosity increased as the fraction of the smaller comonomer increased. For the MePPG2/MePPG3 copolymer, an increase in fractional free volume increased the fluidity. The heterogeneous copolymers (PEG/PPG copolymers) obeyed the Doolittle equation, while the homogeneous (PEG/PEG and PPG/PPG) copolymers did not. The increase of FFV did not, however, correspond to an increase in conductivity, as would have been predicted by the Forsythe equation. The conductivity data did correspond to a modified Forsythe equation substituting Volume Fraction of Ether (V(f,ether)) for FFV. We conclude that the proton conductivity of MePEG copolymers is more dependent on the volume fraction of ether than on the fractional free volume.

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“…Polyethylene glycol (PEG) (also known as poly(ethylene oxide) (PEO) in its long chain form) is a water-soluble polymer that has been widely studied for its interesting properties in aqueous environments. These properties include interactions of its ethylene oxide (EO) chains in aqueous solutions, − the ability to adsorb on surfaces and interfaces, and proton conductivity in polymer electrolytes. − The interaction of water with the PEG chain backbone has been widely studied to date, both by experiment ,, and simulation ,− due to the interesting ability of PEG to form bridged hydrogen bonds (HBs) from EO monomer units to water molecules to other EO monomer units within the same chain . These properties give PEG a wide variety of applications such as biphasic (two-phase) liquid–liquid catalysis, electrochemical energy conversion as a proton exchange membrane additive, − , and in drug delivery via modification of therapeutic molecules (known as PEGylation). − …”

Section: Introductionmentioning

confidence: 99%

“…6−18 The interaction of water with the PEG chain backbone has been widely studied to date, both by experiment 2,3,19 and simulation 4,20−26 due to the interesting ability of PEG to form bridged hydrogen bonds (HBs) from EO monomer units to water molecules to other EO monomer units within the same chain. 4 These properties give PEG a wide variety of applications such as biphasic (twophase) liquid−liquid catalysis, 27 electrochemical energy conversion as a proton exchange membrane additive, [8][9][10][11][12][13][14]28 and in drug delivery via modification of therapeutic molecules (known as PEGylation). 29−31 The conductivity of various ions with PEG in aqueous solution has also been of research interest in past years.…”

Section: Introductionmentioning

confidence: 99%

Ab Initio Molecular Dynamics Simulations of an Excess Proton in a Triethylene Glycol–Water Solution: Solvation Structure, Mechanism, and Kinetics

McDonnell

Keffer

2016

J. Phys. Chem. B

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We investigate the solvation shell structures, the distribution of protonic defects, mechanistic details, kinetics, and dynamics of proton transfer for an excess proton in bulk water and for an excess proton in an aqueous solution of triethylene glycol (TEG) via Car-Parrinello molecular dynamics simulations. The PW91, PBE, and PBE with the Tkatchenko-Scheffler (TS) density-dependent dispersion functionals were used and compared for bulk water and the TEG-water mixtures. The excess proton is found to reside predominantly on water molecules but also resides on hydroxyl groups of TEG. The lifetimes associated with structural diffusion time scales of the protonated water were found to be on the order of ∼1 ps. All three functionals studied support the presolvation requirement for structural diffusion. The highest level of theory shows a reduction in the free energy barrier for water-water proton transfer in TEG-water mixtures compared to bulk water. The effect of TEG shows no strong change in the kinetics for TEG-water mixtures compared to bulk water for this same level of theory. The excess proton displays burst-rest behavior in the presence of TEG, similar to that found in bulk water. We find that the TEG chain disrupts the hydrogen-bond network, causing the solvation shell around water to be populated by TEG chain groups instead of other waters, reducing the rigidity of the hydrogen-bond network. Methylene is a dominant hydrogen bond donor for the protonated water in hydrogen-bond networks associated with proton transfer and structural diffusion. This is consistent with previous studies that have found the hydronium ion to be amphiphilic in nature and to have higher proton mobility at oil-water interfaces.

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Polyethylene glycol-functionalized polyoctahedral silsesquioxanes as H+-conducting electrolytes

Cited by 5 publications

References 27 publications

Electrospun Nd³⁺‐Doped LiMn₂O₄ Nanofibers as High‐Performance Cathode Material for Li‐Ion Capacitors

Electrospun Nd³⁺‐Doped LiMn₂O₄ Nanofibers as High‐Performance Cathode Material for Li‐Ion Capacitors

Volume Fraction of Ether Is a Significant Factor in Controlling Conductivity in Proton Conducting Polyether Based Polymer Sol–Gel Electrolytes

Ab Initio Molecular Dynamics Simulations of an Excess Proton in a Triethylene Glycol–Water Solution: Solvation Structure, Mechanism, and Kinetics

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Polyethylene glycol-functionalized polyoctahedral silsesquioxanes as H+-conducting electrolytes

Cited by 5 publications

References 27 publications

Electrospun Nd3+‐Doped LiMn2O4 Nanofibers as High‐Performance Cathode Material for Li‐Ion Capacitors

Electrospun Nd3+‐Doped LiMn2O4 Nanofibers as High‐Performance Cathode Material for Li‐Ion Capacitors

Volume Fraction of Ether Is a Significant Factor in Controlling Conductivity in Proton Conducting Polyether Based Polymer Sol–Gel Electrolytes

Ab Initio Molecular Dynamics Simulations of an Excess Proton in a Triethylene Glycol–Water Solution: Solvation Structure, Mechanism, and Kinetics

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Product

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Electrospun Nd³⁺‐Doped LiMn₂O₄ Nanofibers as High‐Performance Cathode Material for Li‐Ion Capacitors

Electrospun Nd³⁺‐Doped LiMn₂O₄ Nanofibers as High‐Performance Cathode Material for Li‐Ion Capacitors