| 1. |
- Kim, Jae-Kwang, 1978, et al.
(författare)
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Highly porous LiMnPO4 in combination with an ionic liquid-based polymer gel electrolyte for lithium batteries
- 2011
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Ingår i: Electrochemistry Communications. - : Elsevier BV. - 1388-2481. ; 13:10, s. 1105-1108
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Tidskriftsartikel (refereegranskat)abstract
- A porous well defined LiMnPO(4) cathode material is synthesized by a sol-gel method. The electrochemical performance of the cathode material is evaluated in a cell with an ionic liquid-based polymer electrolyte (0.5 M LITFSI in EMlmTFSI) and a lithium metal electrode. The results are compared to a cell with a traditional organic carbonate-based electrolyte (1 M LiPF(6) in EC/DMC). The cell with the ionic liquid-based polymer electrolyte presents an enhanced electrochemical intercalation performance of lithium ions, a high electrochemical stability window of 5 V, and an excellent cycling ability as compared with the organic based counterpart. Furthermore, the ionic liquid-based polymer gel electrolyte effectively prevents the dissolution of manganese - otherwise a common problem.
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| 2. |
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| 3. |
- Martinelli, Anna, 1978, et al.
(författare)
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Conformational evolution of TFSI− in protic and aprotic ionic liquids
- 2011
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Ingår i: Journal of Raman Spectroscopy. - 0377-0486 .- 1097-4555.
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Tidskriftsartikel (refereegranskat)abstract
- We here report on the conformational evolution of the bis(trifluoromethanesulfonyl)imide anion (TFSI−) in protic and aprotic TFSI−-based ionic liquids as a function of temperature. The investigation is performed by Raman spectroscopy in the spectral ranges 240-380 cm−1 and 715-765 cm−1, where the interference from bands due to the cations is negligible. The contribution from each TFSI− conformation, i.e. the cisoid (C1) and the transoid (C2), is quantified in order to estimate the enthalpy of conformational change, ΔH, which is found to be in the range 3.4–7.3 kJ/mol in the liquid state. Conformational information is for the first time determined from the 740 cm−1 band, which previously mainly has been used as an indicator of ion-ion interactions. The similarity in ΔH values obtained from the two spectral ranges demonstrates the validity of using also the 740 cm−1 band for the quantification of the TFSI conformational evolution.
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| 4. |
- Nordström, Jonas, 1980, et al.
(författare)
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Concentration- and pH-dependence of highly alkaline sodium silicate solutions
- 2011
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Ingår i: Journal of Colloid and Interface Science. - : Elsevier BV. - 0021-9797 .- 1095-7103. ; 356:1, s. 37-45
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Tidskriftsartikel (refereegranskat)abstract
- In this study two routes for the gelation of water glass have been investigated; the destabilization by a change in pH and by an increase in concentration through evaporation. Both methods produce optically transparent, highly viscous, homogeneous solutions. The structure and dynamics of the solutions along the two routes have been investigated with Dynamic Light Scattering, 29Si-Nuclear Magnetic Resonance spectroscopy, viscosity measurements and infrared spectroscopy. We find that the two routes are fundamentally different. Increasing the concentration of the sodium silicate system leaves the silica speciation apparently unchanged. Lowering the pH leads to condensation reactions, thus a change in the silica speciation.
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| 5. |
- Scheers, Johan, 1979, et al.
(författare)
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Ionic liquids and oligomer electrolytes based on the B(CN)(4)(-) anion; ion association, physical and electrochemical propertiesw
- 2011
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Ingår i: Physical Chemistry Chemical Physics. - : Royal Society of Chemistry (RSC). - 1463-9084 .- 1463-9076. ; 13:33, s. 14953-14959
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Tidskriftsartikel (refereegranskat)abstract
- The role of B(CN)(4)(-) (Bison) as a component of battery electrolytes is addressed by investigating the ionic conductivity and phase behaviour of ionic liquids (ILs), ion association mechanisms, and the electrochemical stability and cycling properties of LiBison based electrochemical cells. For C(4)mpyrBison and C(2)mimBison ILs, and mixtures thereof, high ionic conductivities (3.4
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