| 1. |
- Arvidsson, Rickard, 1984, et al.
(författare)
-
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)
-
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. |
- Sandahl, Johan, 1974-, et al.
(författare)
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Överdrivna slutsatser om gymnasieelevers demokratikunskaper
- 2022
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Ingår i: Skola & Samhälle [S.O.S] Webbtidskrift. - : Föreningen Skola & Samhälle - webbtidskrift. - 2001-6727.
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Rapporten från Stiftelsen Rättsfonden om gymnasieelevers kunskaper om demokrati har både metodologiska och teoretiska brister. Eftersom rapporten saknar stöd för flera av de rekommendationer som lämnas är risken att föreslagna förändringar inte gör någon skillnad eller i värsta fall leder i fel riktning, skriver Johan Sandahl med flera, alla forskare i samhällsvetenskapernas didaktik.
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| 4. |
- Wagner, Annemarie, 1954, et al.
(författare)
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Carbon Dioxide Capture from Ambient Air Using Amine-Grafted Mesoporous Adsorbents
- 2013
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Ingår i: International Journal of Spectroscopy. - : Hindawi Limited. - 1687-9457 .- 1687-9449. ; 2013
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Tidskriftsartikel (refereegranskat)abstract
- Anthropogenic emissions of carbon dioxide (CO2) have been identified as a major contributor to climate change. An attractive approach to tackle the increasing levels of CO2 in the atmosphere is direct extraction via absorption of CO2 from ambient air, to be subsequently desorbed and processed under controlled conditions. The feasibility of this approach depends on the sorbent material that should combine a long lifetime with nontoxicity, high selectivity for CO2, and favorable thermodynamic cycling properties. Adsorbents based on pore-expanded mesoporous silica grafted with amines have previously been found to combine high CO2 adsorption capacity at low partial pressures with operational stability under highly defined laboratory conditions. Here we examine the real potential and functionality of these materials by using more realistic conditions using both pure CO2, synthetic air, and, most importantly, ambient air. Through a combination of thermogravimetric analysis and Fourier transform infrared (TGA-FTIR) spectroscopy we address the primary functionality and by diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy the observed degradation of the material on a molecular level.
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| 5. |
- Wickerts, Sanna, 1992, et al.
(författare)
-
Energy storage with less metal scarcity? Prospective life cycle assessment of lithium-sulfur batteries with a focus on mineral resources.
- 2021
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In order to reduce the global dependency on fossil fuels by adopting renewable energy technologies and advancing electromobility, batteries are a key technology. Lithium-ion batteries (LIBs) are currently the dominant rechargeable battery technology, mainly due to their high energy density. However, most LIBs contain a number of geochemically scarce metals, e.g.cobalt, lithium and nickel. The production of LIBs is furthermore associated with considerable environmental impacts. Battery researchers and companies therefore try to develop the next generation batteries (NGBs) with the same or even higher energy densities than LIBs, while requiring less of scarce metals and causing lower environmental impacts. One promising NGB technology is the lithium-sulfur (Li-S) battery, with a potential to significantly improve energy density as compared to current state-of-the-art LIBs. Although Li-S batteries still face a number of scientific and technical challenges, they have a significant advantage over LIBs from a resource point of view: the cells do not require any scarce metals besides lithium. Using prospective life cycle assessment, we will assess the life-cycle environmental impacts of Li-S batteries and compare them to those of LIBs, both modeled at large-scale production. In order to investigate the effect of using less scarce metals on resource impacts, the mineral resource impact category will be given extra attention. We will therefore include a range of mineral resource impact assessment methods, e.g. the abiotic depletion indicator, the surplus ore indicator, and the recently developed crustal scarcity indicator, which takes an explicit long-term perspective on elemental resources in the Earth’s crust. The overall aim is thus to compare the prospective life-cycle impacts of this particular NGB to those of LIBs, with a focus on mineral resources.
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| 6. |
- Wickerts, Sanna, 1992, et al.
(författare)
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How environmentally friendly are batteries with no rare or critical materials?
- 2022
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Rechargeable batteries are increasingly used in a number of applications, such as consumer electronics, electric vehicles, and stationary energy storage. An increased use in the latter two applications is envisioned to reduce greenhouse gas emissions.However, the dominant rechargeable battery technology – the lithium-ion battery (LIB) – impacts the environment in several ways throughout its life cycle. In addition, LIBs require critical and/or geochemically scarce materials, such as lithium, natural graphite, and sometimes nickel and cobalt. One promising next generation battery (NGB) is the sodium-ion battery (SIB). While other NGBs can provide higher energy densities, the SIB technology holds great promise from a resource point of view, since it can be made to contain mostly low-cost, abundant and readily available elements, such as sodium and iron. In addition, the manufacturing processes and equipment developed for LIBs can in principle be re-used, enabling convenient scale-up of production. We here assess the life-cycle impacts of a specific SIB with a low content of scarce metals using prospective life cycle assessment (LCA). The SIB is assumed to be a mature technology produced at large scale and this we accomplish by using data from a small-scale producer and scale these up using available large-scale factory data for LIB production. We use a functional unit of 1 kWh of installed battery cell storage capacity and focus on climate and mineral resource impacts, since those have been highlighted in several publications and guidance documents as particularly important to address in LCAs of batteries. Different shares of renewables are considered in energy supply scenarios, along with scenarios for specific energy density developments. The impacts are compared to those of large-scale produced LIBs and to another NGB – the lithium-sulfur battery. To investigate mineral resource impacts of the different technologies in depth, we include two resource impact assessment methods, the crustal scarcity indicator and the surplus ore potential. The aims of the study are (i) to assess the prospective life cycle impacts of the SIB technology in order to reveal whether it is preferable to other battery technologies from an environmental and resource point of view, and (ii) to understand the environmental profile of the SIB in order to identify hotspots.
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| 7. |
- Wickerts, Sanna, 1992, et al.
(författare)
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Prospective Life Cycle Assessment of Lithium-Sulfur Batteries for Stationary Energy Storage
- 2023
-
Ingår i: ACS Sustainable Chemistry & Engineering. - 2168-0485. ; 11:26, s. 9553-9563
-
Tidskriftsartikel (refereegranskat)abstract
- The lithium-sulfur (Li-S) battery represents a promisingnext-generationbattery technology because it can reach high energy densities withoutcontaining any rare metals besides lithium. These aspects could giveLi-S batteries a vantage point from an environmental and resourceperspective as compared to lithium-ion batteries (LIBs). Whereas LIBsare currently produced at a large scale, Li-S batteries are not. Therefore,prospective life cycle assessment (LCA) was used to assess the environmentaland resource scarcity impacts of Li-S batteries produced at a largescale for both a cradle-to-gate and a cradle-to-grave scope. Six scenarioswere constructed to account for potential developments, with the overallaim of identifying parameters that reduce (future) environmental andresource impacts. The specific energy density and the type of electrolytesalt are the two most important parameters for reducing cradle-to-gateimpacts, whereas for the cradle-to-grave scope, the electricity source,the cycle life, and, again, the specific energy density, are the mostimportant. Additionally, we find that hydrometallurgical recyclingof Li-S batteries could be beneficial for lowering mineral resourceimpacts but not necessarily for lowering other environmental impacts. Life cycle assessment of lithium-sulfurbatteries indicatesa similar environmental impact but a potentially lower mineral resourceimpact compared to lithium-ion batteries.
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| 8. |
- Wickerts, Sanna, 1992, et al.
(författare)
-
Prospective life cycle assessment of sodium-ion batteries made from abundant elements
- 2024
-
Ingår i: Journal of Industrial Ecology. - 1530-9290 .- 1088-1980. ; 28:1, s. 116-129
-
Tidskriftsartikel (refereegranskat)abstract
- Batteries are enablers for reducing fossil-fuel dependency and climate-change impacts. In this study, a prospective life cycle assessment (LCA) of large-scale production of two different sodium-ion battery (SIB) cells is performed with a cradle-to-gate system boundary. The SIB cells modeled have Prussian white cathodes and hard carbon anodes based only on abundant elements and thus constitute potentially preferable options to current lithium-ion battery (LIB) cells from a mineral resource scarcity point of view. The functional unit was 1 kWh theoretical electricity storage capacity, and the specific energy density of the cells was 160 Wh/kg. Data for the cathode active material come from a large-scale facility under construction and data for the SIB cell production is based on a large-scale LIB cell gigafactory. For other SIB cell materials, prospective inventory data was obtained from a generic eight-step procedure developed, which can be used by other LCA practitioners. The results show that both SIB cells indeed have considerably lower mineral resource scarcity impacts than nickel-manganese-cobalt (NMC)-type LIB cells in a cradle-to-gate perspective, while their global warming impacts are on par. Main recommendations to SIB manufacturers are to source fossil-free electricity for cell production and use hard carbon anodes based on lignin instead of phenolic resin. Additionally, since none of the assessed electrolytes had clearly lower cradle-to-gate impacts than any other, more research into SIB electrolyte materials with low environmental and resource impacts should be prioritized. An improvement of the SIB cell production model would be to obtain large-scale production data specific to SIB cells.
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| 9. |
- Adebahr, Josefina, 1973, et al.
(författare)
-
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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| 10. |
- Ahmad Ishfaq, Hafiz, 1995, et al.
(författare)
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Enhanced performance of lithium metal batteries via cyclic fluorinated ether based electrolytes
- 2024
-
Ingår i: Energy Storage Materials. - 2405-8297. ; 69
-
Tidskriftsartikel (refereegranskat)abstract
- To address the challenges associated with applying high-voltage cathodes in lithium metal batteries (LMBs) there is a need for new electrolytes enabling stable interphases at both electrodes. Here we attack this by using a dioxolane-derived cyclic fluorinated ether, 2,2-bis(trifluoromethyl)-1,3-dioxolane (BTFD), as a fluorinated diluent to a 1,2-dimethoxyethane (DME) based electrolyte. The cells using the resulting BTFD-based electrolytes exhibit higher Coulombic efficiencies for lithium stripping and plating as compared to those using the non-fluorinated ether-based electrolyte. This originates from the reduced formation of ‘dead Li’ at the anode, as shown by using electrochemical impedance spectroscopy (EIS). In practice, the BTFD-based electrolytes are shown to improve the performance of Li||NMC cells, which is due to the formation of a predominantly inorganic cathode electrolyte interphase (CEI) that suppresses the cathode degradation during cycling. We used X-ray photoelectron spectroscopy (XPS) and scanning transmission electron microscopy (STEM) to characterize the CEIs’ overall composition and structure. To obtain more details on the CEI speciation, Raman and nuclear magnetic resonance (NMR) spectroscopies were employed, assisted by molecular level computations. Overall, we demonstrate how the very design of the electrolyte composition influences the performance of LMBs.
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| 11. |
- Ahmed, Mukhtiar, et al.
(författare)
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Aromatic Heterocyclic Anion Based Ionic Liquids and Electrolytes
- 2023
-
Ingår i: Physical Chemistry, Chemical Physics - PCCP. - : Royal Society of Chemistry. - 1463-9076 .- 1463-9084. ; 25:4, s. 3502-3512
-
Tidskriftsartikel (refereegranskat)abstract
- Five new ionic materials comprising fluorine-free aromatic heterocyclic anions based on pyridine and pyrazine combined with a common n-tetrabutylphosphonium cation, (P4444)+, result in two room temperature ionic liquids (RTILs), one semi-solid, and two organic ionic plastic crystals (OIPCs) with melting points >20 °C. The OIPCs showed a plastic crystalline phase, multiple solid–solid transitions, and plastic crystalline and melt phases. For both the neat RTILs and the Li+ conducting electrolytes, the nature and strength of the ion–ion interactions mainly depend on the position of the nitrogen atom with respect to the carboxylate group in the anions. Furthermore, for the RTILs the ionic conductivity is effected by the electronic structure and flexibility of the ions and the anions diffuse faster than the (P4444)+ cation, but are slowed down in the electrolytes due to the strong electrostatic interactions between the carboxylate group of the anions and the Li+, as shown both experimentally and computationally. Overall, this study describes the effect of structural tuning of aromatic anions on the ion–ion interactions and introduces new ionic materials with promising properties to be used as solid and liquid electrolytes in energy storage devices.
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| 12. |
- Ahmed, Mukhtiar, et al.
(författare)
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Ionic Liquids and Electrolytes with Flexible Aromatic Anions
- 2023
-
Ingår i: Chemistry - A European Journal. - : John Wiley & Sons. - 0947-6539 .- 1521-3765. ; 29:41
-
Tidskriftsartikel (refereegranskat)abstract
- Five new n-tetrabutylphosphonium (P4444)+ cation based ionic liquids (ILs) with oligoether substituted aromatic carboxylate anions have been synthesized. The nature and position of the oligoether chain affect thermal stability (up to 330 ºC), phase behaviour (Tg < -55 ºC) and ion transport. Furthermore, with the aim of application in lithium batteries, electrolytes were created for two of the ILs by 10 mol% doping using the corresponding Li-salts. This affects the ion diffusion negatively, from being higher and equal for cations and anions to lower for all ions and unequal. This is due to the stronger ionic interactions and formation of aggregates, primarily between the Li+ ions and the carboxylate group of the anions. Electrochemically, the electrolytes have electrochemical stability windows up to 3.5 V, giving some promise for battery application.
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| 13. |
- Ahmed, Mukhtiar, et al.
(författare)
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Pyrrolidium- and Imidazolium-Based Ionic Liquids and Electrolytes with Flexible Oligoether Anions
- 2024
-
Ingår i: ChemPhysChem. - : John Wiley & Sons. - 1439-7641 .- 1439-4235. ; 25:9
-
Tidskriftsartikel (refereegranskat)abstract
- A new class of fluorine-free ionic liquids (ILs) and electrolytes based on aliphatic flexible oligoether anions, 2-(2-methoxyethoxy)acetate (MEA) and 2-[2-(2-methoxyethoxy)ethoxy]acetate (MEEA), coupled with pyrrolidinium and imidazolium cations is introduced. For the ILs with MEEA anions, Li+ conducting electrolytes are created by doping the ILs with 30 mol % of LiMEEA. The structural flexibility of the oligoether functionality in the anion results in glass transition temperatures (Tg) as low as −60 °C for the neat ILs and the electrolytes. The imidazolium-based ILs and electrolytes reveal better thermal stabilities but higher Tg and lower electrochemical stabilities than the corresponding pyrrolidinium-based analogues. All neat ILs show comparable transport properties for the cations and these decrease by the addition of lithium salt – the pyrrolidinium-based electrolyte being affected the most.
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| 14. |
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| 15. |
- Alvi, Sajid, 1987, et al.
(författare)
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Entropy Stabilized Medium High Entropy Alloy Anodes for Lithium-Ion Batteries
- 2024
-
Ingår i: Batteries & Supercaps. - : John Wiley & Sons. - 2566-6223. ; 7:5
-
Tidskriftsartikel (refereegranskat)abstract
- One often proposed route to improved energy density for lithium-ion batteries is to use alloy anodes, such as silicon, able to store large amounts of lithium. Mechanical instability caused by the large expansion and contraction associated with (de)lithiation, and hence bad cyclability, has, however, so far hindered progress. As proof-of-concept of a remedy, we here present BiSbSe1.5Te1.5, a medium high-entropy alloy with improved cycling stability for conversion-alloying (de)lithiation reactions. We attain five to twenty times more stable cycles than previously reported for comparable metal-Se and -Te-based anodes, with a very good reversible capacity (464 mAh g−1) for up to 110 cycles- and this without using any carbonaceous materials to create a composite. Altogether, this highlights how alloy engineering and increased entropy materials can stabilize conversion-alloying electrodes.
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| 16. |
- 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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| 17. |
- Andersson, Markus, 1981, et al.
(författare)
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Coordination of Imidazoles by Cu(II) and Zn(II) as Studied by NMR Relaxometry, EPR, far-FTIR Vibrational Spectroscopy and Ab Initio Calculations: Effect of Methyl Substitution
- 2010
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Ingår i: Journal of Physical Chemistry A. - : American Chemical Society (ACS). - 1089-5639 .- 1520-5215. ; 114:50, s. 13146-13153
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Tidskriftsartikel (refereegranskat)abstract
- Synthetic imidazole ligands are typically substituted at the N-1 ((1)-Im) position while natural imidazole ligands are substituted at the C-4 ((4)-Im) position. To outline the difference in coordination properties, the methyl-substituted imidazoles Me(4)-Im and Me(1)-Im were complexed with CuCl2 and ZnCl2 and investigated by NMR relaxometry, electron paramagnetic resonance, far-Fourier transform IR vibrational spectroscopy, and ab initio calculations. Me(4)-Im, Me(1)-Im, and Im in excess form the usual tetragonal D-4h [CuL4X2] complexes with CuCl2 whereas the methylated imidazoles form pseudotetrahedral C-2v, complexes instead of the usual octahedral O-h [ZnIm(6)](2+) complex. All imidazoles display a high degree of covalence in the M-L sigma- and pi-bonds and the pi-interaction strength affects the relative energies of complexation. Opportunities to tailor complexes by the chemical properties of the substituents are envisaged due to the role of the inductive and hyperconjugative effects, rather than position.
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| 18. |
- Andersson, Rasmus, 1990, et al.
(författare)
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CHAMPION: Chalmers hierarchical atomic, molecular, polymeric and ionic analysis toolkit
- 2021
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Ingår i: Journal of Computational Chemistry. - : Wiley. - 0192-8651 .- 1096-987X. ; 42:23, s. 1632-1642
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Tidskriftsartikel (refereegranskat)abstract
- We present CHAMPION (Chalmers hierarchical atomic, molecular, polymeric, and ionic analysis toolkit): a software developed to automatically detect time-dependent bonds between atoms based on their dynamics, classify the local graph topology around them, and analyze the physicochemical properties of these topologies by statistical physics. In stark contrast to methodologies where bonds are detected based on static conditions such as cut-off distances, CHAMPION considers pairs of atoms to be bound only if they move together and act as a bound pair over time. Furthermore, the time-dependent global bond graph is possible to split into dynamically shifting connected components or subgraphs around a certain chemical motif and thereby allow the physicochemical properties of each such topology to be analyzed by statistical physics. Applicable to condensed matter and liquids in general, and electrolytes in particular, this allows both quantitative and qualitative descriptions of local structure, as well as dynamical processes such as speciation and diffusion. We present here a detailed overview of CHAMPION, including its underlying methodology, implementation, and capabilities.
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| 19. |
- Andersson, Rasmus, 1990, et al.
(författare)
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Dynamic Structure Discovery Applied to the Ion Transport in the Ubiquitous Lithium-ion Battery Electrolyte LP30
- 2022
-
Ingår i: Journal of the Electrochemical Society. - : The Electrochemical Society. - 1945-7111 .- 0013-4651. ; 169:10
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Tidskriftsartikel (refereegranskat)abstract
- The electrolytes of the today omnipresent lithium-ion batteries (LIBs) have for more than 25 years been based upon 1 M LiPF6 in a 50:50 EC:DMC mixture-commonly known as LP30. The success of the basic design of the LP30 electrolyte, with many variations and additions made over the years, is unchallenged. Yet, some molecular level fundamentals of LP30 are surprisingly elusive: the structure of the first solvation shell of the Li+ cation is still a topic of current debate; the details of the dynamics are not fully understood; the interpretation of structural and dynamic properties is highly dependent on the analysis methods used; the contributions by different species to the ion transport and the energetics involved are not established. We here apply dynamic structure discovery analysis as implemented in CHAMPION to molecular dynamics simulation trajectories to bring new light on the structure and dynamics within LP30 and especially the (Li+) ion transport to rationalize further development of LIB electrolytes.
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| 20. |
- Andersson, Rasmus, 1990, et al.
(författare)
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Ion Transport Mechanisms via Time-Dependent Local Structure and Dynamics in Highly Concentrated Electrolytes
- 2020
-
Ingår i: Journal of the Electrochemical Society. - : The Electrochemical Society. - 1945-7111 .- 0013-4651. ; 167:14
-
Tidskriftsartikel (refereegranskat)abstract
- Highly concentrated electrolytes (HCEs) are attracting interest as safer and more stable alternatives to current lithium-ion battery electrolytes, but their structure, solvation dynamics and ion transport mechanisms are arguably more complex. We here present a novel general method for analyzing both the structure and the dynamics, and ultimately the ion transport mechanism(s), of electrolytes including HCEs. This is based on automated detection of bonds, both covalent and coordination bonds, including how they dynamically change, in molecular dynamics (MD) simulation trajectories. We thereafter classify distinct local structures by their bond topology and characterize their physicochemical properties by statistical mechanics, giving both a qualitative and quantitative description of the structure, solvation and coordination dynamics, and ion transport mechanism(s). We demonstrate the method by in detail analyzing an ab initio MD simulation trajectory of an HCE consisting of the LiTFSI salt dissolved in acetonitrile at a 1:2 molar ratio. We find this electrolyte to form a flexible percolating network which limits vehicular ion transport but enables the Li+ ions to move between different TFSI coordination sites along with their first solvation shells. In contrast, the TFSI anions are immobilized in the network, but often free to rotate which further facilitates the Li+ hopping mechanism.Highly concentrated electrolytes (HCEs) are attracting interest as safer and more stable alternatives to current lithium-ion battery electrolytes, but their structure, solvation dynamics and ion transport mechanisms are arguably more complex. We here present a novel general method for analyzing both the structure and the dynamics, and ultimately the ion transport mechanism(s), of electrolytes including HCEs. This is based on automated detection of bonds, both covalent and coordination bonds, including how they dynamically change, in molecular dynamics (MD) simulation trajectories. We thereafter classify distinct local structures by their bond topology and characterize their physicochemical properties by statistical mechanics, giving both a qualitative and quantitative description of the structure, solvation and coordination dynamics, and ion transport mechanism(s). We demonstrate the method by in detail analyzing an ab initio MD simulation trajectory of an HCE consisting of the LiTFSI salt dissolved in acetonitrile at a 1:2 molar ratio. We find this electrolyte to form a flexible percolating network which limits vehicular ion transport but enables the Li+ ions to move between different TFSI coordination sites along with their first solvation shells. In contrast, the TFSI anions are immobilized in the network, but often free to rotate which further facilitates the Li+ hopping mechanism. Highly concentrated electrolytes (HCEs) are attracting interest as safer and more stable alternatives to current lithium-ion battery electrolytes, but their structure, solvation dynamics and ion transport mechanisms are arguably more complex. We here present a novel general method for analyzing both the structure and the dynamics, and ultimately the ion transport mechanism(s), of electrolytes including HCEs. This is based on automated detection of bonds, both covalent and coordination bonds, including how they dynamically change, in molecular dynamics (MD) simulation trajectories. We thereafter classify distinct local structures by their bond topology and characterize their physicochemical properties by statistical mechanics, giving both a qualitative and quantitative description of the structure, solvation and coordination dynamics, and ion transport mechanism(s). We demonstrate the method by in detail analyzing an ab initio MD simulation trajectory of an HCE consisting of the LiTFSI salt dissolved in acetonitrile at a 1:2 molar ratio. We find this electrolyte to form a flexible percolating network which limits vehicular ion transport but enables the Li+ ions to move between different TFSI coordination sites along with their first solvation shells. In contrast, the TFSI anions are immobilized in the network, but often free to rotate which further facilitates the Li+ hopping mechanism.
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| 21. |
- Angenendt, Knut, 1982, et al.
(författare)
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Ionic Liquid Based Lithium Battery Electrolytes: Charge Carriers and Interactions Derived by Density Functional Theory Calculations
- 2011
-
Ingår i: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-5207 .- 1520-6106. ; 115:24, s. 7808-7813
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Tidskriftsartikel (refereegranskat)abstract
- The solvation of lithium salts in ionic liquids (ILs) leads to the creation of a lithium ion carrying species quite different from those found in traditional nonaqueous lithium battery electrolytes. The most striking differences are that these species are composed only of ions and in general negatively charged. In many IL-based electrolytes, the dominant species are triplets, and the charge, stability, and size of the triplets have a large impact on the total ion conductivity, the lithium ion mobility, and also the lithium ion delivery at the electrode. As an inherent advantage, the triplets can be altered by selecting lithium salts and ionic liquids with different anions. Thus, within certain limits, the lithium ion carrying species can even be tailored toward distinct important properties for battery application. Here, we show by DFT calculations that the resulting charge carrying species from combinations of ionic liquids and lithium salts and also some resulting electrolyte properties can be predicted.
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| 22. |
- Angenendt, Knut, 1982, et al.
(författare)
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Ionic liquid structures from large DFT calculations using mindless configurations
- 2010
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Ingår i: Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 114:48, s. 20577-20582
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Tidskriftsartikel (refereegranskat)abstract
- Three different popular imidazolium based ionic liquids (ILs); EMI-BF4, EMI-PF6, and EMI-TFSI, have been modeled by DFT calculations (B3LYP/6-311+G*) using large, up to 130 atom cluster models, for a better understanding of the structure and ion ion interactions in these ILs and ILs in general. Particular emphasis has been put on the role of appropriate starting structures and how the present large models differ from the ion-pair models of ILs generally used. The system size normalized ion ion interaction energies are shown to converge rapidly, and conformational equilibria and higher order properties like IR spectra are shown to be valuable as quality criteria. The explicit inclusion of an IL environment by the large cluster approach is also compared to using an implicit, continuum, strategy via SCRF C-PCM calculations.
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| 23. |
- Armand, M., et al.
(författare)
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Review-Development of Huckel Type Anions: From Molecular Modeling to Industrial Commercialization. A Success Story
- 2020
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Ingår i: Journal of the Electrochemical Society. - : The Electrochemical Society. - 1945-7111 .- 0013-4651. ; 167:7
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Forskningsöversikt (refereegranskat)abstract
- This paper reviews the battery electrolyte technologies involving Huckel-type salts as a major electrolyte component. The concept was initially proposed by M. Armand in 1995 and then explored by several research groups. In the present review studies on the optimization of the electrolyte composition starting from molecular modeling through enhancing the yield of the salt synthesis to structural characterization and electrochemical performance are described. Furthermore, the use of the optimized electrolytes in a variety of lithium-ion and post-lithium batteries is presented and discussed. Finally, the commercialization of the up to date technology by Arkema is discussed as well as the performance of the present Huckel anion based electrolytes as compared to other marketed electrolyte technologies.
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| 24. |
- Arroyo-De Dompablo, M. Elena, et al.
(författare)
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Achievements, Challenges, and Prospects of Calcium Batteries
- 2020
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Ingår i: Chemical Reviews. - : American Chemical Society (ACS). - 0009-2665 .- 1520-6890. ; 120:14, s. 6331-6357
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Forskningsöversikt (refereegranskat)abstract
- This Review flows from past attempts to develop a (rechargeable) battery technology based on Ca via crucial breakthroughs to arrive at a comprehensive discussion of the current challenges at hand. The realization of a rechargeable Ca battery technology primarily requires identification and development of suitable electrodes and electrolytes, which is why we here cover the progress starting from the fundamental electrode/electrolyte requirements, concepts, materials, and compositions employed and finally a critical analysis of the state-of-the-art, allowing us to conclude with the particular roadblocks still existing. As for crucial breakthroughs, reversible plating and stripping of calcium at the metal-anode interface was achieved only recently and for very specific electrolyte formulations. Therefore, while much of the current research aims at finding suitable cathodes to achieve proof-of-concept for a full Ca battery, the spectrum of electrolytes researched is also expanded. Compatibility of cell components is essential, and to ensure this, proper characterization is needed, which requires design of a multitude of reliable experimental setups and sometimes methodology development beyond that of other next generation battery technologies. Finally, we conclude with recommendations for future strategies to make best use of the current advances in materials science combined with computational design, electrochemistry, and battery engineering, all to propel the Ca battery technology to reality and ultimately reach its full potential for energy storage.
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| 25. |
- 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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