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- Martinelli, Anna, 1978, et al.
(författare)
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Structural analysis of PVA-based proton conducting membranes
- 2006
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Ingår i: Solid State Ionics. - : Elsevier BV. - 0167-2738. ; 177:26-32, s. 2431-2435
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Tidskriftsartikel (refereegranskat)abstract
- We have synthesized and characterized a new family of proton conducting membranes based on cross-linked poly(vinyl alcohol), PVA, and functionalized silica filler. Glutaraldehyde, GLA, was used as the cross-linking agent in order to improve chemical and thermal stabilities. The functionalization of the silica particles is such that terminal -SO 3 H groups are formed during membrane preparation, thus possibly providing additional mobile protons. We find that the crystallinity of the PVA-based membranes is enhanced by the presence of the functionalized silica particles, whereas it is reduced by means of cross-linking. The thermal stability of the ternary system PVA:GLA:silica is improved due to the additive contribution of GLA and silica. The conductivity of membranes swelled in a sulfuric acid solution was found to be of the order of 10 - 1 S cm - 1 . © 2006 Elsevier B.V. All rights reserved.
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| 2. |
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| 3. |
- Agostini, Marco, 1987, et al.
(författare)
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A high-power and fast charging Li-ion battery with outstanding cycle-life
- 2017
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322 .- 2045-2322. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- Electrochemical energy storage devices based on Li-ion cells currently power almost all electronic devices and power tools. The development of new Li-ion cell configurations by incorporating innovative functional components (electrode materials and electrolyte formulations) will allow to bring this technology beyond mobile electronics and to boost performance largely beyond the state-of-theart. Here we demonstrate a new full Li-ion cell constituted by a high-potential cathode material, i.e. LiNi0.5Mn1.5O4, a safe nanostructured anode material, i.e. TiO2, and a composite electrolyte made by a mixture of an ionic liquid suitable for high potential applications, i.e. Pyr(1),4PF6, a lithium salt, i.e. LiPF6, and standard organic carbonates. The final cell configuration is able to reversibly cycle lithium for thousands of cycles at 1000 mAg(-1) and a capacity retention of 65% at cycle 2000.
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| 4. |
- Lombardo, L., et al.
(författare)
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In-situ gelled electrolyte for lithium battery: Electrochemical and Raman characterization
- 2014
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Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753. ; 245, s. 232-235
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Tidskriftsartikel (refereegranskat)abstract
- n this paper we report a polymer lithium cell using a PVdF-based, gel-type electrolyte formed in-situ during cell assembly. The gel electrolyte formation is monitored prior to cell assembly by electro-chemical impedance spectroscopy and by Raman spectroscopy in order to determine the characteristics of the lithium salt diffusion into the gel-membrane. The results show an efficient gel formation and a fast lithium salt diffusion, this finally resulting in an optimized behaviour in a lithium cell using a high voltage spinel-type cathode. We believe that the results here reported may contribute to the enhancement of the safety of lithium batteries. (C) 2013 Elsevier B.V. All rights reserved.
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| 5. |
- Martinelli, Anna, 1978, et al.
(författare)
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A structural study on ionic-liquid-based polymer electrolyte membranes
- 2007
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Ingår i: Journal of the Electrochemical Society. - : The Electrochemical Society. - 1945-7111 .- 0013-4651. ; 154:8, s. G183-G187
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Tidskriftsartikel (refereegranskat)abstract
- We have investigated novel proton conducting membranes synthesized through the gelification of poly(vinylidene fluoride-co-hexafluoropropylene) in aprotic ionic liquids. Mobile protons were introduced by doping the system with the strong bis(trifluoromethanesulfonyl)imide acid (HTFSI), which is chemically compatible with the ionic liquids through the common TFSI- anion. The obtained membranes are thermally stable up to 115°C set by the melting of the polymer phase. At this temperature, the conductivity is on the order of 10-2 S cm-1. Raman and infrared spectroscopy show no chemical interactions between the components, indicating that the bulklike nature of the doped ionic liquids preserved within the membrane, as is the thermal stability and the high conductivity. © 2007 The Electrochemical Society.
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| 6. |
- Martinelli, Anna, 1978, et al.
(författare)
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A study on the state of PWA in PVDF-based proton conducting membranes by Raman spectroscopy
- 2007
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Ingår i: Solid State Ionics. - : Elsevier BV. - 0167-2738. ; 178:7-10, s. 527-531
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Tidskriftsartikel (refereegranskat)abstract
- Polymer composite proton conducting membranes with increasing amount of tungstophosphoric acid (PWA) have been synthesized starting from poly(vinylidene) fluoride and alumina. Membranes could be prepared with an acid loading up to 16.7 wt.%. The conductivity of the membranes increases with acid loading up to 10- 3 Scm- 1 at the highest loading. The membrane matrices have a good thermal stability up to 240 °C, however a loss of water absorbed during the preparation procedure is observed at a considerably lower temperature. Raman spectroscopy showed that in the membrane the polymer adopts a conformation that could promote a separation into hydrophilic/hydrophobic sites. An interaction between alumina and PWA is also found that might limit the conductivity of the membranes.
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