| 1. |
- Arvidsson, Rickard, 1984, et al.
(författare)
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Energy use and climate change improvements of Li/S batteries based on life cycle assessment
- 2018
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Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753. ; 383, s. 87-92
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Tidskriftsartikel (refereegranskat)abstract
- We present a life cycle assessment (LCA) study of a lithium/sulfur (Li/S) cell regarding its energy use (in electricity equivalents, kWhel) and climate change (in kg carbon dioxide equivalents, CO2 eq) with the aim of identifying improvement potentials. Possible improvements are illustrated by departing from a base case of Li/S battery design, electricity from coal power, and heat from natural gas. In the base case, energy use is calculated at 580 kWhel kWh−1 and climate change impact at 230 kg CO2 eq kWh−1 of storage capacity. The main contribution to energy use comes from the LiTFSI electrolyte salt production and the main contribution to climate change is electricity use during the cell production stage. By (i) reducing cell production electricity requirement, (ii) sourcing electricity and heat from renewable sources, (iii) improving the specific energy of the Li/S cell, and (iv) switching to carbon black for the cathode, energy use and climate change impact can be reduced by 54 and 93%, respectively. For climate change, our best-case result of 17 kg CO2 eq kWh−1 is of similar magnitude as the best-case literature results for lithium-ion batteries (LIBs). The lithium metal requirement of Li/S batteries and LIBs are also of similar magnitude.
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| 2. |
- Arvidsson, Rickard, 1984, et al.
(författare)
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Potential improvements of the life cycle environmental impacts of a Li/S battery cell
- 2018
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The lithium sulfur (Li/S) battery is a promising battery chemistry for two reasons: it requires no scarce metals apart from the lithium itself and it brings the promise of high specific energy density at the cell level. However, the environmental impacts of this battery type remain largely unstudied. In this study, we conducted a life cycle assessment (LCA) of the production of an Li/S cell to calculate these impacts. The anode consists of a lithium foil and the cathode consists of a carbon/sulfur composite. The electrolyte is a mixture of dioxalane, dimethoxyethane, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and lithium nitrate. The current collector for the cathode is an aluminium foil and a tri-layer membrane of polypropylene and polyethylene acts as separator. The functional unit of the study is 1 kWh specific energy storage. Three key environmental impacts were considered: energy use, climate change and lithium requirement. In our baseline scenario, we consider the pilot-scale production of a battery with a specific energy of 300 kWh/kg, having the mesoporous material CMK-3 as carbon material in the carbon/sulfur cathode, and using coal power and natural gas heat as energy sources. This scenario results in an energy use of 580 kWh/kWhstored and a climate change impact of 230 kg CO2eq/kWhstored. The main contributor to energy use is the LiTFSI production and the main contributor to climate change is electricity use during cell production. We then model a number of possible improvements sequentially: (1) reduction of cell production electricity requirement due to production at industrial-scale, (2) sourcing of electricity and heat from renewable instead of fossil sources (i.e. solar power and biogas heat), (3) improvement of the specific energy of the Li/S cell to 500 kWh/kg and (4) a shift of the carbon material in the cathode to carbon black (without considering changes in performance). By implementing all these four improvements, energy use and climate change impact can be reduced by an impressive 54 and 93%, respectively. In particular, the improvements related to industrial-scale production and sourcing of renewable energy are considerable, whereas the shift of carbon material is of minor importance. For climate change, the best-case result of 17 kg CO2eq/kWhstored is similar to the best-case results reported in the scientific literature for lithium-ion batteries (LIBs). Regarding lithium requirement, the lithium metal requirement of Li/S batteries and LIBs are also of similar magnitude (0.33-0.55 kg/kWhstored and 0.2 kg/kWhstored, respectively). Using different allocation approaches did not alter the main conclusions of the study.
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| 3. |
- Amin, Muhammad, 1979, et al.
(författare)
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Coin-cell Supercapacitors Based on CVD Grown and Vertically Aligned Carbon Nanofibers (VACNFs)
- 2017
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Ingår i: International Journal of Electrochemical Science. - : Elsevier BV. - 1452-3981. ; 12:7, s. 6653-6661
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Tidskriftsartikel (refereegranskat)abstract
- Complete supercapacitors (SCs) comprising vertically aligned carbon nanofibers (VACNFs) as electrode materials have been assembled as coin-cells. The VACNFs were grown directly onto the current collector by direct current plasma enhanced chemical vapor deposition (DC-PECVD), thereby providing excellent contact with the current collector, but also eliminating the need of any binder. The vertical alignment facilitates fast ion transport and the electrolyte to access the entire surface of the CNFs. The morphology of the VACNFs was evaluated by scanning electron microscopy (SEM), while the performance was assessed by several methods: cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and device related cycling by galvanostatic charge/discharge. The capacitance, 3.64 mF/cm2 , is >15 times higher than the capacitance of a coin-cell without CNFs and the cyclic performance shows these proof-of-concept SCs to retain >80% of the capacitance after 2000 full charge/discharge cycles. The direct growth of VACNFs as electrodes at the current collector opens pathways for SC production using existing coin-cell battery production technology.
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| 4. |
- Asghar, Naveed, 1983-, et al.
(författare)
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Local landscape effects on population dynamics of Ixodes ricinus
- 2016
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Ingår i: Geospatial health. - : Page Press Publications. - 1827-1987 .- 1970-7096. ; 11:3, s. 283-289
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Tidskriftsartikel (refereegranskat)abstract
- Ixodes ricinus, a common tick in Europe, transmits severe tickborne pathogens (TBPs). In Sweden, both prevalence and incidence of tick-borne infections have increased during the last few decades, and a majority of the cases is reported from the area around Stockholm. Among ticks, transmission of TBPs involves co-feeding of susceptible larvae or nymphs with infected ticks on the same host. Seasonal synchrony of immature stages and total tick abundance are important factors for the probability of horizontal transmission of TBPs. We have studied the association between local landscape characteristics and population dynamics and the probability of co-occurrence of different life cycle stages of I. ricinus at different locations south of Stockholm, Sweden. We found significant spatiotemporal variation in tick activity patterns. Mean tick abundance varied with a tenfold difference among study sites. The probability of co-occurrence of larvae, nymphs and female adults was highest in June and decreased significantly with vegetation height. In addition, the amount of forest habitat and open water in the surrounding landscape of the study sites expressed significant negative effects on tick abundance and co-occurrence, indicating that environmental heterogeneity may increase the likelihood of good rodent habitats, which in turn, are suitable hosts for immature ticks.
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| 5. |
- Bergman, Martin, 1985, et al.
(författare)
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Graft copolymer electrolytes for high temperature Li-battery applications, using poly(methyl methacrylate) grafted poly(ethylene glycol)methyl ether methacrylate and lithium bis(trifluoromethanesulfonimide)
- 2015
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Ingår i: Electrochimica Acta. - : Elsevier BV. - 0013-4686 .- 1873-3859. ; 175, s. 96-103
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Tidskriftsartikel (refereegranskat)abstract
- For successful hybridization of heavy vehicles, high temperature batteries might be the solution. Here, high temperature solid polymer electrolytes (SPE's) based on different ratios of poly(methyl methacrylate) (PMMA) and poly(ethylene glycol) methyl ether methacrylate (PEGMA), with LiTFSI salt (at a fixed ether oxygen (EO):Li ratio of 20:1) have been prepared and investigated. The copolymers comprise PMMA backbones with grafted PEGMA side-chains containing 9 EO units. The SPE systems were characterized using Raman spectroscopy, broadband dielectric spectroscopy, differential scanning calorimetry, thermal gravimetric analysis, and electrochemical cycling in prototype cells, with a particular focus on the 83 wt% PEGMA system. The electrolytes have good thermal stabilities and dissociate the LiTFSI salt easily, while at the same time maintaining low glass transition temperatures (Tg's). Depending on the polymeric structure, ionic conductivities >1 mS cm-1 at 110 °C are detected, thus providing ion transport properties for a broad range of electrochemical applications. Prototype Li|polymer electrolyte|LiFePO4 cells utilizing the SPE at 60 °C showed surprisingly low capacities (
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| 6. |
- Boschin, Andrea, 1981, et al.
(författare)
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Characterization of NaX (X: TFSI, FSI) - PEO based solid polymer electrolytes for sodium batteries
- 2015
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Ingår i: Electrochimica Acta. - : Elsevier BV. - 0013-4686. ; 175, s. 124-133
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Tidskriftsartikel (refereegranskat)abstract
- Solid polymers electrolytes (SPEs) based on sodium bis(fluorosulfonyl) imide (NaFSI) and poly(ethylene oxide) (PEO) with different ether oxygen to sodium (O:Na) molar ratios (n), resulting in NaFSI(PEO) n materials are here presented for the first time. These SPEs are extensively compared with the corresponding NaTFSI(PEO)(n) system in terms of ionic conductivities, thermal properties, and charge carriers - to in detail outline both the role of the different anions used and the salt concentrations employed. While for the most dilute systems (n = 20) the two SPE families show similar ionic conductivities in the entire temperature range investigated (273-343 K), for n = 6 and n = 9 they differ significantly; at room temperature, the NaFSI based SPEs show lower ionic conductivities than the NaTFSI based analogues. This difference is mainly ascribed to differences in the morphology; while the NaTFSI salt, possibly by virtue of its large TFSI anion, acts to inhibit crystallization, NaFSI rather seems to favor crystallization. Furthermore, careful Raman spectroscopy analysis of the charge carrier speciation reveal higher aggregates to be present in the most concentrated SPE, NaFSI(PEO)(6), and the NaFSI based SPEs in general to result in less "free" anions than the NaTFSI based SPEs. Moreover, as both NaTFSI(PEO)(n) and NaFSI(PEO)(n) for n = 20 and n = 9 exhibit very similar glass transition temperatures, the FSI ion seem to be equally plasticizing as the TFSI ion, but for n = 6 the different speciation in terms of charge carriers also affects the relative dynamics of the polymer chains.
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| 7. |
- Boschin, Andrea, 1981, et al.
(författare)
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On the Feasibility of Sodium Metal as Pseudo-Reference Electrode in Solid State Electrochemical Cells
- 2017
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Ingår i: ChemElectroChem. - : Wiley. - 2196-0216. ; 4:10, s. 2717-2721
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Tidskriftsartikel (refereegranskat)abstract
- A set-up of a sodium metal anode vs. a solid polymer electrolyte (SPE) comprising poly(ethylene oxide) (PEO) and sodium bis(trifluoromethanesulfonyl)imide (NaTFSI) has been evaluated in detail for the feasibility to use sodium metal as a pseudo-reference electrode (pseudo-RE). To evaluate the stability and reproducibility, we monitored the half-wave potential (E-1/2) of added decamethylferrocene (Me(10)Fc) and the stability of the interface by electrochemical impedance spectroscopy (EIS). The sodium/SPE interface resistance (R-Na/SPE) increases with time, up to 2.8k Omega cm(-2), and causes the E-1/2 of the Me(10)Fc(+/0) reference redox couple to drift up to 15mV during 88hours. Moreover, the sodium potential is very irreproducible, even initially after cell assembling the values can differ by 60mV, likely due to extreme sensitivity of the metal surface even to an "inert and dry" glove box environment. Indeed, freshly cut sodium readily reacts with water, forming NaOH, and adsorbs impurities that can be present even in a glove box atmosphere. The oxidation layer and the amount of adsorbed impurities increase with the exposure to the glove box atmosphere, as revealed by ATR-FTIR spectroscopy. Altogether, this calls for attention when evaluating any battery materials in half-cell configurations using sodium metal as the pseudo-RE.
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| 8. |
- Boschin, Andrea, 1981, et al.
(författare)
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Plasticization of NaX-PEO solid polymer electrolytes by Pyr(13)X ionic liquids
- 2016
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Ingår i: Electrochimica Acta. - : Elsevier BV. - 0013-4686. ; 211, s. 1006-1015
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Tidskriftsartikel (refereegranskat)abstract
- Addition of moderate contents (≤20 wt%) of ionic liquids (ILs) to binary solid polymer electrolytes (SPEs) is made to alter the overall SPE properties, foremost to increase the room temperature ionic conductivity. Sodium conducting ternary electrolytes, based on sodium salts; NaTFSI and NaFSI, the polymer poly(ethylene oxide) (PEO), and pyrrolidinium ILs; Pyr13TFSI and Pyr13FSI, with different compositions: NaX(PEO)n – Pyr13X (X = TFSI, FSI), have been prepared. Raman and dielectric spectroscopy as well as differential scanning calorimetry have been used to evaluate the plasticizing effect of the Pyr13 IL cation and the accompanying TFSI and FSI IL anions via changes in ionic association, crystallinity, polymer chain dynamics, and total ionic conductivity. While all the TFSI based systems seem rather insensitive to the addition of IL with respect to speciation, the situation is much less clear for the FSI based systems. Furthermore, the addition of ILs seems beneficial for inhibiting PEO crystallization, especially for the FSI anion, and also for enhancing the polymer chain dynamics, but yet the FSI based ternary electrolytes show lower ion conductivities as compared to the analogous TFSI based systems.
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| 9. |
- Böhme, Solveig, et al.
(författare)
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Lithium-ion batteries based on SnO2 electrodes and a LiTFSI-Pip14TFSI ionic liquid electrolyte
- 2017
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Ingår i: Journal of the Electrochemical Society. - : The Electrochemical Society. - 1945-7111 .- 0013-4651. ; 164:4, s. A701-A708
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Tidskriftsartikel (refereegranskat)abstract
- The performance of lithium-ion batteries (LIBs) comprising SnO2 electrodes and an ionic liquid (IL) based electrolyte, i.e., 0.5 M LiTFSI in Pip14TFSI, has been studied at room temperature (i.e., 22°C) and 80°C. While the high viscosity and low conductivity of the electrolyte resulted in high overpotentials and low capacities at room temperature, the SnO2 performance at 80°C was found to be analogous to that seen at room temperature using a standard LP40 electrolyte (i.e., 1 M LiPF6 dissolved in 1:1 ethylene carbonate and diethyl carbonate). Significant reduction of the IL was, however, found at 80°C, which resulted in low coulombic efficiencies during the first 20 cycles, most likely due to a growing SEI layer and the formation of soluble IL reduction products. X-ray photoelectron spectroscopy studies of the cycled SnO2 electrodes indicated the presence of an at least 10 nm thick solid electrolyte interphase (SEI) layer composed of inorganic components such as lithium fluoride, sulfates, and nitrides as well as organic species containing C-H, C-F and C-N bonds.
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| 10. |
- Cznotka, E., et al.
(författare)
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3D laser scanning confocal microscopy of siloxane-based comb and double-comb polymers in PVDF-HFP thin films
- 2016
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Ingår i: Journal of Coatings Technology Research. - : Springer Science and Business Media LLC. - 1935-3804 .- 1547-0091. ; 13:4, s. 577-587
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Tidskriftsartikel (refereegranskat)abstract
- Currently, atomic force microscopy is the preferred technique to determine roughness on membrane surfaces. In this paper, a new method to measure surface roughness is presented using a 3D laser scanning confocal microscope for high-resolution topographic analysis and is compared to conventional SEM. For this study, the surfaces of eight samples based on a poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) host polymer with different liquid interpenetrating components were analyzed. Polymethylhydrosiloxane, triethylene glycolallylmethyether, (3,3,3-trifluoropropyl) methylcyclotrisiloxane (D-3-C2H4CF3), polysiloxane-comb-propyloxymethoxytriglycol (PSx), poly-siloxane-comb-propyl-3,3,3-trifluoro (PSx-C2H4CF3), poly [bis(2-(2-methoxyethoxy) ethoxy) phosphazene, or poly [bis(trifluoro) ethoxy] phosphazene was chosen as interpenetrating compound to investigate the impact of comb and double-comb-structured polymer backbones, as well as their dipolar or fluorous residues on the PVDF-HFP-miscibility. Different phases of the constituting ingredients were identified via their thermal properties determined by DSC. Additionally, the COSMO-RS method supported the experimental results, and with regard to computed sigma-profiles, new modified structures for polysiloxane and polyphosphazene synthesis were suggested.
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