| 1. |
- 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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| 2. |
- Hosseini Bab Anari, Elham, 1982, et al.
(författare)
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Fluorine-free salts for aqueous lithium-ion and sodium-ion battery electrolytes
- 2016
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Ingår i: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 6:88, s. 6, 85194-85201
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Tidskriftsartikel (refereegranskat)abstract
- A first generation of fluorine-free lithium and sodium salts based on the concept of pseudo-delocalized anions has been synthesized with both high purity and yield using water as the solvent in the reaction medium. The salts have been fully characterized by Raman and FT-IR spectroscopies, thermogravimetry, and X-ray crystallography to reveal both basic properties in terms of thermal stability and solubility as well as the local, mainly ion–ion interaction dictated, coordination details and by ionic conductivity and electrochemical stability window measurements as aqueous electrolytes. Together a picture is created of the salts' promise as components in electrolytes – primarily aiming at application in low voltage fluorinefree aqueous lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs).
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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. |
- 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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| 5. |
- Ciosek, Katarzyna, et al.
(författare)
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Energy storage activities in the Swedish hybrid vehicle centre
- 2009
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Ingår i: World Electric Vehicle Journal. - : MDPI AG. - 2032-6653. ; 3:4, s. 858-862, s. 2850-2854
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Tidskriftsartikel (refereegranskat)abstract
- Significant efforts are put worldwide on developing new concepts for vehicle propulsion with the hybrid electric vehicle (HEV) being a prominent example. Hybrid technology is clearly a strategic future activity for automotive industries and in response to the rapid development in the area; the Swedish Hybrid Vehicle Centre (SHC) was formed in 2007 to join forces between Swedish industry and academia in the field. The centre emphasizes a holistic view to meet the environmental and societal needs with new technological solutions. The research within SHC is currently divided into three different themes whereof we here describe the Energy Storage theme with emphasis on the activities carried out at the involved universities in the current main project areas: Cell Properties, Electrode Materials and Electrolyte Additives. Examples are given on how these projects attacks the problems at hand separately, but also how we create synergy effects between the projects. As an example cell modelling is performed given a specific chemistry and cycling scheme, the same parameters are used for electrochemical experiments which provide macroscopic data that are connected with molecular level actions in the electrodes, the electrolyte, and the interfaces. All this is done using our base-line chemistry and a subsequent route is to investigate the role of different additives to overcome the limitations that are observed.
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| 6. |
- Forero-Saboya, Juan, et al.
(författare)
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Interfaces and Interphases in Ca and Mg Batteries
- 2022
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Ingår i: Advanced Materials Interfaces. - : Wiley. - 2196-7350. ; 9:8
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Forskningsöversikt (refereegranskat)abstract
- The development of high energy density battery technologies based on divalent metals as the negative electrode is very appealing. Ca and Mg are especially interesting choices due to their combination of low standard reduction potential and natural abundance. One particular problem stalling the technological development of these batteries is the low efficiency of plating/stripping at the negative electrode, which relates to several factors that have not yet been looked at systematically; the nature/concentration of the electrolyte, which determines the mass transport of electro-active species (cation complexes) toward the electrode; the possible presence of passivation layers, which may hinder ionic transport and hence limit electrodeposition; and the mechanisms behind the charge transfer leading to nucleation/growth of the metal. Different electrolytes are investigated for Mg and Ca, with the presence/absence of chlorides in the formulation playing a crucial role in the cation desolvation. From a R&D point-of-view, proper characterization alongside modeling is crucial to understand the phenomena determining the mechanisms of the plating/stripping processes. The state-of-the-art is here presented together with a short perspective on the influence of the cation solvation also on the positive electrode and finally an attempt to define guidelines for future research in the field.
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| 7. |
- Jeschke, Steffen, 1986, et al.
(författare)
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Supervised Machine Learning-Based Classification of Li-S Battery Electrolytes
- 2021
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Ingår i: Batteries and Supercaps. - : Wiley. - 2566-6223. ; 4:7, s. 1156-1162
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Tidskriftsartikel (refereegranskat)abstract
- Machine learning (ML) approaches have the potential to create a paradigm shift in science, especially for multi-variable problems at different levels. Modern battery R&D is an area intrinsically dependent on proper understanding of many different molecular level phenomena and processes alongside evaluation of application level performance: energy, power, efficiency, life-length, etc. One very promising battery technology is Li-S batteries, but the polysulfide solubility in the electrolyte must be managed. Today, many different electrolyte compositions and concepts are evaluated, but often in a more or less trial-and-error fashion. Herein, we show how supervised ML can be applied to accurately classify different Li-S battery electrolytes a priori based on predicting polysulfide solubility. The developed framework is a combined density functional theory (DFT) and statistical mechanics (COSMO-RS) based quantitative structure-property relationship (QSPR) model which easily can be extended to other battery technologies and electrolyte properties.
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| 8. |
- Johansson, Patrik, 1969, et al.
(författare)
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Lithium–Sulfur Battery Electrolytes
- 2017
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Ingår i: Li-S Batteries: The Challenges, Chemistry, Materials and Future Perspectives. ; , s. 149-194
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The electrolyte is at the very heart of any battery concept physically, but more and more also mentally amongst battery researchers and developers. This is largely due to the growing insight that many problems related to overall efficiency, life-length, and safety often originate in the electrolyte. This is perhaps even more a truth for the Lithium-Sulfur (Li–S) battery technology and hence large efforts are today focused on novel Li–S battery electrolytes — materials as well as concepts. In this chapter we will start by summarizing the similarities and differences in demands and design as compared to the Li-ion battery (LIB) technology, as the latter is more familiar to most readers. We then move to two large sections of liquid and solid electrolytes, respectively, outlining the materials and methods used. In each of the sections we point to a few specific topics and how these are researched today, keeping the comparison with the LIB as a way to more easily understand the unique features/issues/problems that electrolytes for Li–S batteries are facing. The chapter is made at a level and limited to a scope where the open literature is sufficient and plentiful, but of course studying the patent literature and gaining the hidden industry know-how may definitively extend the scope for the interested reader. Overall we hope that after reading this chapter, armed with a basic knowledge of the types of electrolytes and the materials presently in use in Li–S batteries, it will be easier for the reader to understand the needs, limitations, problems, but also the possibilities. This should finally open for suggestions of how to rationally improve the electrolytes with in the end enhanced performance of future Li–S batteries.
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| 9. |
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| 10. |
- Åvall, Gustav, 1988, et al.
(författare)
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Sodium-Ion Battery Electrolytes: Modeling and Simulations
- 2018
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Ingår i: Advanced Energy Materials. - : Wiley. - 1614-6840 .- 1614-6832. ; 8:17
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Forskningsöversikt (refereegranskat)abstract
- The authors review the efforts made from a modeling and simulation perspective in order to assist both the fundamental understanding as well as the development of higher performance sodium-ion battery (SIB) electrolytes. Depending on the type of the electrolyte studied, liquid, ionic liquid, polymer, glass, solid-state, etc., the simulation methods applied and the research questions in focus differ, but all contribute to more rational progress. Furthermore, the authors create cases of meta-analysis using literature data. A historical perspective is applied and the focus clearly is on more recent work and novel electrolyte materials. Finally, the authors outline a few prospective areas for where SIB electrolyte simulations can/should be extended for maximum impact in the field.
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