| 1. |
- Johansson, Patrik, 1969, et al.
(författare)
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Ten Ways to Fool the Masses When Presenting Battery Research
- 2021
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Ingår i: Batteries and Supercaps. - : Wiley. - 2566-6223. ; 4:12, s. 1785 -1788
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- As scientists within the field of battery research we may often find it quite difficult to match and trust the promises given in press releases and high-profile papers. Even though there are real breakthroughs, where the results indeed are as impressive as they are marketed to be, we may as often find the reporting of "revolutionary" results to omit critical aspects of the methods and materials used. The absolute majority of researchers do not actively pursue to present their science in any untrue fashion, but poor (ethical) judgement could affect anyone working long hours in a gloomy lab at dusk and at the same time feel being pressed for publications and citations. Here, we outline ten ways to make your results appear more attractive and ground-breaking than they actually are, especially to laypeople that might not appreciate the full range of difficulties associated with battery research. Consider it a light-hearted entry with respect to scientific quality in methodology and dissemination, that might assist you in looking for nebulous reporting practices in your own and your peers' work, but please do not consider it a guide, but a humorous contrast to the real publishing guidelines recently launched
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| 2. |
- Westman, Kasper, 1990, et al.
(författare)
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Diglyme based electrolytes for sodium-ion batteries
- 2018
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Ingår i: ACS Applied Energy Materials. - : American Chemical Society (ACS). - 2574-0962. ; 1:6, s. 2671-2680
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Tidskriftsartikel (refereegranskat)abstract
- Sodium-ion batteries (SIBs) are currently being considered for large-scale energy storage. Optimization of SIB electrolytes is, however, still largely lacking. Here we exhaustively evaluate NaPF6 in diglyme as an electrolyte of choice, via both physicochemical properties and extensive electrochemical tests including half as well as full cells. Fundamentally, the ionic conductivity is found to be quite comparable to carbonate based electrolytes and to obey the fractional Walden rule with viscosity. We find Na metal to work well as a reference electrode and the electrochemical stability, evaluated potentiostatically for various electrodes and corroborated by DFT calculations, to be satisfactory in the entire voltage range 0-4.4 V. Galvanostatic cycling at C/10 of half and full cells using Na3V2(PO4)(3) (NVP) or Na3V2(PO4)(2)F-3 (NVPF) as cathodes and hard carbon (HC) as anodes indicates rapid capacity fading in cells with HC anodes, possibly originating in a lack of a stable SEI or by trapping of sodium. Aiming to understand this capacity fade further, we conducted a GC/MS analysis to determine electrolyte reduction products and to propose reduction pathways, concluding that oligomer and/or alkoxide formation is possible. Overall, the promising results should warrant further investigations of diglyme based electrolytes for modern SIB development, albeit avoiding HC anodes.
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| 3. |
- Westman, Kasper, 1990
(författare)
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Enabling collection of data – from lab to field – to forecast battery ageing
- 2024
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- By 2030, the battery industry is predicted to have an annual output of over 4 TWh of storage capacity, thus supporting the ”electrify everything” paradigm. This comes with societal benefits such as lower CO2-emissions in the end applic- ations, but also with risks of over-consumption and too high life-cycle emissions. Thus, making sure that batteries last longer by mitigating degradation is paramount. Here we explore how mechanistic understanding of degradation can be gained and effectively communicated for use in a battery digital twin (BDT), in it’s turn capable of predicting future battery degradation and suggest mitigating actions. This is achieved by conducting a campaign of lab-based experiments to identify relevant degradation modes. Simultaneously a battery information format (BIF) suited for field application is developed within the scope of this thesis. The BIF is framed so as to respect both qualitative and quantitat- ive needs existing in battery powered applications and those from a broader informatics perspective. The knowledge about degradation modes are success- ively encoded into a graphical causal model (GCM) that is consequently used to define the binning scheme of the BIF-compatible histograms, enabling a memory-efficient data-collection strategy. The method is showcased for a Hard Carbon and Na3V2(PO4)2F3 sodium- ion battery, utilizing 1 M NaPF6 as electrolyte, and identifying degradation using electrochemical techniques (e.g. galvanostatic cycling and electrical impedance spectroscopy), coupled gas-chromatography/mass spectrometry, in- frared spectroscopy, and EDX analysis. Subsequently the mentioned translation into a BIF-compatible data collection strategy is carried out. For next steps we suggest doing a field deployment of the strategy, either with the investigated chemistry or with commercial cells of a similar chemistry, so as to validate the BIF concept.
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