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- Larsson, Carl, 1997, et al.
(author)
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Effects of lithium insertion induced swelling of a structural battery negative electrode
- 2023
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In: Composites Science and Technology. - 0266-3538. ; 244
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Journal article (peer-reviewed)abstract
- Structural battery composites fall under the category multifunctional materials with the ability to simultaneously store electrical energy and carry mechanical load. While functioning as the negative electrode, the carbon fibres also act as mechanical reinforcement. Lithium ion insertion in the carbon fibres is accompanied by a large radial expansion of 6.6 % and an axial expansion of 0.85 % of the fibres. Furthermore, the elastic moduli of the carbon fibres are significantly affected by the insertion of lithium. Current structural battery modelling approaches do not consider these features. In this paper, we investigate the effect of lithium insertion in carbon fibres on the structural electrode mechanical properties by developing a computational model considering finite strains and lithium concentration dependent fibre moduli. The computational model enables representation of morphological change, whereby, features such as internal stress state, homogenized tangent stiffness and effective expansion of the electrode caused by carbon fibre lithiation can be predicted. The adopted finite strain formulation allows for consistent consideration of measurement data at varying state of lithiation. The significance of adopting the finite strain formulation is also shown numerically. Finally, by implementing a novel approach to homogenized stress-free expansion, it is shown that the computed expansion of the structural electrode follows a similar trend to what is observed from experiments.
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- Bobis Camacho, Julián, 1997, et al.
(author)
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Evaluation of culture conditions for sewage-based surveillance of antibiotic resistance in Klebsiella pneumoniae.
- 2024
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In: Journal of global antimicrobial resistance. - 2213-7173.
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Journal article (peer-reviewed)abstract
- Recent studies have shown promise in predicting clinical antibiotic resistance rates from sewage data. Few have focused on Klebsiella pneumoniae, despite its virulence and importance as carrier of antibiotic resistance. Several media have been suggested for the isolation of K. pneumoniae from complex samples. However, comprehensive evaluations of culture protocols for isolation of K. pneumoniae from sewage are lacking.Here, influent samples from a major Swedish sewage treatment plant were used to evaluate ten culture conditions in parallel: cultivation on Brilliant green containing Inositol-Nitrate-Deoxycholate agar (BIND), Bruce agar, Klebsiella ChromoSelect Selective agar®, MacConkey-Inositol-Carbenicillin, or Simmons Citrate Agar with Inositol (SCAI) incubated at either 37˚C or 42˚C for 44 h. The culture conditions were compared based on colony counts of presumed K. pneumoniae and identification precision assessed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.The sensitivity was lowest for BIND, whereas it was similar for the other media irrespective of incubation temperature. For four media, a better precision was observed after incubation at 42˚C compared to 37˚C, to a large extent explained by a lower frequency of captured Klebsiella oxytoca. SCAI incubated at 42˚C showed the highest precision (84.4%). By combining this protocol with subsequent antibiotic resistance screening of collected isolates, low resistance rates in sewage K. pneumoniae were revealed, potentially reflecting the local resistance landscape.When combined with downstream analyses, SCAI incubated at 42˚C could be a valuable culture protocol for sewage-based studies on various aspects of K. pneumoniae epidemiology including antibiotic resistance prevalence.
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4. |
- Huijbers, Patricia, 1985, et al.
(author)
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Sampling Considerations for Wastewater Surveillance of Antibiotic Resistance in Fecal Bacteria
- 2023
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In: International Journal of Environmental Research and Public Health. - : MDPI AG. - 1661-7827 .- 1660-4601. ; 20:5
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Journal article (peer-reviewed)abstract
- Wastewaters can be analyzed to generate population-level data for public health surveillance, such as antibiotic resistance monitoring. To provide representative data for the contributing population, bacterial isolates collected from wastewater should originate from different individuals and not be distorted by a selection pressure in the wastewater. Here we use Escherichia coli diversity as a proxy for representativeness when comparing grab and composite sampling at a major municipal wastewater treatment plant influent and an untreated hospital effluent in Gothenburg, Sweden. All municipal samples showed high E. coli diversity irrespective of the sampling method. In contrast, a marked increase in diversity was seen for composite compared to grab samples from the hospital effluent. Virtual resampling also showed the value of collecting fewer isolates on multiple occasions rather than many isolates from a single sample. Time-kill tests where individual E. coli strains were exposed to sterile-filtered hospital wastewater showed rapid killing of antibiotic-susceptible strains and significant selection of multi-resistant strains when incubated at 20 °C, an effect which could be avoided at 4 °C. In conclusion, depending on the wastewater collection site, both sampling method and collection/storage temperature could significantly impact the representativeness of the wastewater sample.
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5. |
- Jutkina, Jekaterina, et al.
(author)
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Conjugative transfer of multi-drug resistance IncN plasmids from environmental waterborne bacteria to Escherichia coli
- 2022
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In: Frontiers in Microbiology. - : Frontiers Media SA. - 1664-302X. ; 13
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Journal article (peer-reviewed)abstract
- Watersheds contaminated with municipal, hospital, and agricultural residues are recognized as reservoirs for bacteria carrying antibiotic resistance genes (ARGs). The objective of this study was to determine the potential of environmental bacterial communities from the highly contaminated La Paz River basin in Bolivia to transfer ARGs to an Escherichia coli lab strain used as the recipient. Additionally, we tested ZnSO4 and CuSO4 at sub-inhibitory concentrations as stressors and analyzed transfer frequencies (TFs), diversity, richness, and acquired resistance profiles. The bacterial communities were collected from surface water in an urban site close to a hospital and near an agricultural area. High transfer potentials of a large set of resistance factors to E. coli were observed at both sites. Whole-genome sequencing revealed that putative plasmids belonging to the incompatibility group N (IncN, IncN2, and IncN3) were predominant among the transconjugants. All IncN variants were verified to be mobile by a second conjugation step. The plasmid backbones were similar to other IncN plasmids isolated worldwide and carried a wide range of ARGs extensively corroborated by phenotypic resistance patterns. Interestingly, all transconjugants also acquired the class 1 integron intl1, which is commonly known as a proxy for anthropogenic pollution. The addition of ZnSO4 and CuSO4 at sub-inhibitory concentrations did not affect the transfer rate. Metal resistance genes were absent from most transconjugants, suggesting a minor role, if any, of metals in the spread of multidrug-resistant plasmids at the investigated sites.
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6. |
- Larsson, Carl, 1997
(author)
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On Nonlinear Modelling of Structural Battery Composites
- 2024
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Licentiate thesis (other academic/artistic)abstract
- Structural battery composites are multifunctional materials with the ability to simultaneously store electrochemical energy and carry mechanical load. A conventional lithium-ion battery comprises a positive electrode, a separator, and a negative electrode. The constituents are soaked in a liquid electrolyte, allowing lithium-ion exchange between the electrodes while electrons travel through an external circuit via current collectors. In structural batteries, the negative electrode is replaced by multifunctional carbon fibres, enabling the additional function as mechanical reinforcement. The liquid electrolyte is replaced by a porous two-phase matrix material. The solid polymer phase transfers mechanical loads between the carbon fibres, and the lithium ions travel in the liquid phase, occupying the pores in the polymer matrix. Redox reactions occur on the electrode/electrolyte interfaces. For instance, reduction of lithium ions forms neutral lithium that diffuses inside the carbon fibres in a charge process of a structural battery full cell. Lithium insertion is accompanied by extensive carbon fibre expansion, which causes internal stresses and affects the elastic moduli of the carbon fibres. In contrast, applying a mechanical load to the lithiated carbon induces a response in the electric potential. In the first paper, we study the effect of the carbon fibre expansion on the surrounding matrix material in a structural negative electrode. In particular, we investigate the significance of adopting non-linear kinematics. In this way, features such as the internal stress state, homogenized tangent stiffness, and expansion of the homogenized negative electrode can be predicted. The second paper concerns multiphysics modelling of a structural battery full cell, that is, a LiFePO4 (lithium-iron-phosphate) based positive electrode against a carbon fibre negative electrode. Specifically, we introduce non-linear reaction kinetics to describe the redox reactions occurring on the electrode / electrolyte interfaces. Moreover, we discuss coupled electro-chemo-mechanical modelling of the positive electrode and the pertinent calibration towards experimental findings.
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7. |
- Siam Siraj, Mohammad, 1993, et al.
(author)
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Advancing Structural Battery Composites: Robust Manufacturing for Enhanced and Consistent Multifunctional Performance
- 2023
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In: Advanced Energy and Sustainability Research. - 2699-9412. ; 4:11
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Journal article (peer-reviewed)abstract
- Multifunctional materials offer a possibility to create lighter and more resource-efficient products and thereby improve energy efficiency. Structural battery composites are one type of such a multifunctional material with potential to offer massless energy storage for electric vehicles and aircraft. Although such materials have been demonstrated, their performance level and consistency must be improved. Also, the cell dimensions need to be increased. Here, we develop a robust manufacturing procedure and repeatedly manufacture structural battery composite cells with double the multifunctional performance and size compared to state-of-the-art structural battery cells. Furthermore, six structural battery cells are selected and laminated into a structural battery composite multicell demonstrator to showcase the technology. The multicell demonstrator performance is characterised for two different electrical configurations. The low variability in the multifunctional properties of the cells verifies the potential for upscaling offered by the proposed manufacture technique.
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