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- Adebahr, Josefina, 1973, et al.
(författare)
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Ab initio calculations, Raman and NMR investigation of the plastic crystal di-methyl pyrrolidinium iodide
- 2003
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Ingår i: Electrochimica Acta. - 0013-4686. ; 48:14-16, s. 2283-2289
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Tidskriftsartikel (refereegranskat)abstract
- Above 110 °C the symmetric di-methyl-pyrrolidinium iodide salt forms a plastic crystal phase of interest in the area of new electrolyte materials. In this study ab initio calculations of this material has been conducted in order to assign the vibrational spectra. Raman spectroscopy measurements on the solid salt as well as on the salt dissolved in different solvents has been performed and these have been compared to the theoretical spectra. Furthermore, Raman spectra as a function of temperature have been recorded to investigate possible changes in inter-ionic interaction and/or structure through the phase transition. 1 H NMR linewidth measurements as a function of temperature showed a large decrease in linewidth above 100 °C, attributed here to an increase in mobility in agreement with a previously reported phase transition at ∼ 110 °C. © 2003 Elsevier Science Ltd. All rights reserved.
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| 3. |
- Johansson, Patrik, 1969, et al.
(författare)
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An ab initio approach to the single ion transport in crystalline LiIPF6PEO6
- 2003
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Ingår i: Electrochimica Acta. - 0013-4686. ; 48:14-16, s. 2279-2281
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Tidskriftsartikel (refereegranskat)abstract
- The lithium ion transport in crystalline LiPF 6 PEO 6 has been modeled by ab initio electronic structure calculations. The activation energy values obtained using a molecular model correspond excellently to experimental values from conductivity measurements. Based on the present results structural modifications in order to further enhance the single ion conductivity are suggested. © 2003 Elsevier Science Ltd. All rights reserved.
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| 10. |
- Johansson, Patrik, 1969, et al.
(författare)
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TiO2 nano-particles in polymer electrolytes: surface interactions
- 2004
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Ingår i: Solid State Ionics. - : Elsevier BV. - 0167-2738. ; 170:1-2, s. 73-78
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Tidskriftsartikel (refereegranskat)abstract
- The effect of nano-sized oxide particles, especially TiO 2 , on the structure and dynamics of polymeric electrolytes such as LiX/PEO has previously been shown to be profound. Here a first attempt is made to investigate the local surface interactions affecting the macroscopically observed properties using a rutile TiO 2 -cluster via ab initio Hartree-Fock (HF) and density functional theory (DFT) (B3LYP) type calculations. As an exploratory work, we use a small Ti 11 O 22 atomistic cluster embedded in point charges (PCs) and the (110) surface for the adsorption process. Out of lithium cations (Li + ), tetrafluoroborate anions (BF 4 - ), and dimethyl ethers (O(CH 3 ) 2 ), BF 4 - is found to be the preferred adsorbate. The ether has comparable energy of adsorption when adjusting for bi-dentate coordination. The present results support the creation of new diffusion pathways for the lithium ion at the nano-particle surfaces and emphasises the possible role of anion adsorption. © 2003 Elsevier B.V. All rights reserved.
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