| 1. |
- Asp, Leif, 1966, et al.
(författare)
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A structural battery and its multifunctional performance
- 2021
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Ingår i: Advanced Energy and Sustainability Research. - : Wiley. - 2699-9412. ; 2:3
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Tidskriftsartikel (refereegranskat)abstract
- Engineering materials that can store electrical energy in structural load paths can revolutionize lightweight design across transport modes. Stiff and strong batteries that use solid-state electrolytes and resilient electrodes and separators are generally lacking. Herein, a structural battery composite with unprecedented multifunctional performance is demonstrated, featuring an energy density of 24 Wh kg-1 and an elastic modulus of 25 GPa and tensile strength exceeding 300 MPa. The structural battery is made from multifunctional constituents, where reinforcing carbon fibers (CFs) act as electrode and current collector. A structural electrolyte is used for load transfer and ion transport and a glass fiber fabric separates the CF electrode from an aluminum foil-supported lithium–iron–phosphate positive electrode. Equipped with these materials, lighter electrical cars, aircraft, and consumer goods can be pursued.
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| 2. |
- Duan, Shanghong, 1992, et al.
(författare)
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BUILDING AND CHARACTERIZATION OF SYMMETRIC STRUCTURAL BATTERY
- 2022
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Ingår i: ECCM 2022 - Proceedings of the 20th European Conference on Composite Materials: Composites Meet Sustainability. ; 3, s. 1169-1174
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Konferensbidrag (refereegranskat)abstract
- Recently, a structural battery with multifunctional carbon fibre anode has been reported. The energy density of active material is not fully extracted due to the low ionic conductivity inside the battery. To identify the main region that attributes to the low ion transportation, we assemble a symmetric structural battery with one anode layer in the centre sandwiched between two cathode layers. Such a design can also be treated as a combination of two asymmetric batteries with one full thickness cathode layer plus one half thickness anode layer. Thus, the travelled distance of lithium ions is shortened only in the anode part. It is found that the area energy density of the symmetric structural battery is doubled compared to a reference asymmetric battery. Thus, the additional cathode layer activates the double amount of carbon fibres in the anode. A plausible reason is that only the carbon fibres next to the separator is activated in the battery.
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| 3. |
- Johansen, Marcus, 1994
(författare)
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Atoms in Lithiated Carbon Fibres
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Carbon fibres are key constituents of structural batteries, in which electrochemical energy storage and mechanical load bearing are merged in one multifunctional device. Here carbon fibres simultaneously act as structural reinforcement by carrying load and as battery electrode by hosting lithium (Li)-ions in its microstructure. However, conventional carbon fibres are not designed to be multifunctional. To enable carbon fibres with optimised multifunctional capabilities, a fundamental understanding of their microstructure, chemical information and interaction with Li is required. In this thesis, mass spectrometry and electron spectroscopy techniques are developed and used to elucidate the atomic distribution, configuration, and interaction in commercial carbon fibres used in structural batteries. Here the methodology of analysing Li in carbon fibres with atom probe tomography (APT) and Auger electron spectroscopy (AES) is demonstrated. Synchrotron-based hard X-ray photoelectron spectroscopy (HAXPES) reveals that certain chemical states of N heteroatoms, pyridinic and pyrrolic, are connected to enhanced electrochemical performance of carbon fibres. AES shows that: Li distributes throughout the entire carbon fibre; the amount of trapped Li is higher and concentrated towards the centre of the fibre at increased discharge rates; Li is initially inserted in amorphous domains and with increased states of lithiation in crystalline domains; and Li plating can occur on individual fibres without spreading to adjacent fibres. APT on lithiated carbon fibres shows that: the distribution of Li is independent of the distribution of N heteroatoms; trapped Li is distributed uniformly in all domains; and Li agglomerates at elevated states of lithiation. The work presented in this thesis paves the way for analysis of carbon-based battery materials with APT and AES. Furthermore, the work unveils much of the interplay between carbon fibre and Li and deepens the understanding of the design parameters for tailoring multifunctional carbon fibres used in improved structural batteries.
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| 4. |
- Johansen, Marcus, 1994, et al.
(författare)
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Best Practices for Analysis of Carbon Fibers by Atom Probe Tomography
- 2022
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Ingår i: Microscopy and Microanalysis. - 1435-8115 .- 1431-9276. ; 28:4, s. 1092 -1101
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Tidskriftsartikel (refereegranskat)abstract
- Carbon fiber technology drives significant development in lightweight and multifunctional applications. However, the microstructure of carbon fibers is not completely understood. A big challenge is to obtain the distribution of heteroatoms, for instance nitrogen, with high spatial resolution in three dimensions. Atom probe tomography (APT) has the potential to meet this challenge, but APT of carbon fibers is still relatively unexplored. We performed APT on three types of carbon fibers, including one high modulus type and two intermediate modulus types. Here, we present the methods to interpret the complex mass spectra of carbon fibers, enhance the mass resolution, and increase the obtained analysis volume. Finally, the origin of multiple hit events and possible methods to mitigate multiple hit events are also discussed. This paper provides guidance for future APT studies on carbon fibers, and thus leads the way to a deeper understanding of the microstructure, and consequently advancements in wide applications of carbon fibers.
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| 5. |
- Johansen, Marcus, 1994, et al.
(författare)
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EFFECT OF LITHIUM INSERTION ON MECHANICAL PROPERTIES OF INDIVIDUAL COMMERCIAL PAN CARBON FIBRES FOR MULTIFUNCTIONAL COMPOSITES
- 2022
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Ingår i: ECCM 2022 - Proceedings of the 20th European Conference on Composite Materials: Composites Meet Sustainability. ; 5, s. 320-327
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Konferensbidrag (refereegranskat)abstract
- Carbon fibres can act simultaneously as structural reinforcement and battery electrode. Such multifunctionality is utilised in structural batteries where energy storing capabilities are integrated into load-carrying components, thus creating “mass-less energy storage”. Lightweight energy storage is desirable for various applications, particularly electric vehicles, whose driving range is heavily inhibited by the weight of conventional lithium-ion battery packs. Structural batteries rely on the ability of carbon fibres to host lithium-ions in their microstructure. Currently, there is a lack in knowledge of how lithium atoms distribute in carbon fibres and what the effects on individual fibres are. Here, with AES and XPS, we elucidate the element distribution in pristine and lithiated T800 PAN-based carbon fibres. Furthermore, mechanical properties are investigated with single filament tensile tests and fractography. It gives an increased understanding of the effect of lithiation on mechanical performance of carbon fibres.
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| 6. |
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| 7. |
- Johansen, Marcus, 1994, et al.
(författare)
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Lithiated carbon fibres for structural batteries characterised with Auger electron spectroscopy
- 2023
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Ingår i: Applied Surface Science. - 0169-4332. ; 627
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Tidskriftsartikel (refereegranskat)abstract
- Structural batteries are multifunctional devices that store energy and carry mechanical load, simultaneously. The pivotal constituent is the carbon fibre, which acts as not only structural reinforcement, but also as electrode by reversibly hosting Li ions. Still, little is known about how Li and carbon fibres interact. Here we map Li inserted in polyacrylonitrile based carbon fibres with Auger electron spectroscopy (AES). We show that with slow charge/discharge rates, Li distributes uniformly in the transverse and longitudinal direction of the fibre, and when fully discharged, all Li is virtually expelled. With fast rates, Li tends to be trapped in the core of the fibre. In some fibres, Li plating is found between the solid electrolyte interphase (SEI) and fibre surface. Our findings can guide AES analysis on other carbonaceous electrode materials for Li-ion batteries and be used to improve the performance of structural batteries.
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| 8. |
- Johansen, Marcus, 1994, et al.
(författare)
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Mapping nitrogen heteroatoms in carbon fibres using atom probe tomography and photoelectron spectroscopy
- 2021
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Ingår i: Carbon. - : Elsevier BV. - 0008-6223. ; 179, s. 20-27
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Tidskriftsartikel (refereegranskat)abstract
- Carbon fibres show great potential as multifunctional negative electrode for novel structural battery composites – a rechargeable electrochemical cell with structural function. The electrochemical performance of carbon materials can be enhanced with nitrogen heteroatoms, which conveniently are inherent in polyacrylonitrile (PAN)-based carbon fibres. However, it is not fully understood how the electrochemical performance is governed by microstructure and composition of the carbon fibres, particularly the distribution and chemical states of nitrogen heteroatoms. Here we reveal the atom-by-atom three-dimensional spatial distribution and the chemical states of nitrogen in three PAN-carbon fibre types (M60J, T800 and IMS65), using atom probe tomography (APT) and synchrotron hard X-ray photoelectron spectroscopy (HAXPES), and correlate the results to electrochemical performance. The findings pave the way for future tailoring of carbon fibre microstructure for multifunctional applications.
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| 9. |
- Johansen, Marcus, 1994
(författare)
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Microstructure of Carbon Fibres for Multifunctional Composites: 3D Distribution and Configuration of Atoms
- 2021
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Lightweight energy storage is a must for increased driving range of electric vehicles. “Mass-less” energy storage can be achieved by directly storing energy in structural components. In such multifunctional devices called structural composite batteries, carbon fibres carry mechanical load and simultaneously act as negative battery electrode by hosting lithium ions in its microstructure. Little is known of how the microstructure of carbon fibres is optimised for multifunctionality, and deeper understanding of the configuration and the distribution of atoms in carbon fibres is needed. Here synchrotron hard X-ray photoelectron spectroscopy and atom probe tomography are used to reveal the chemical states and three-dimensional distribution of atoms in commercial carbon fibres. This thesis presents the first ever guide for how to perform atom probe tomography on carbon fibres, and the first ever three-dimensional atomic reconstruction of a carbon fibre. The results show that the chemical states and distribution of nitrogen heteroatoms in carbon fibres affect the electrochemical performance of the fibres. Carbon fibres performed electrochemically better with higher amount of nitrogen with pyridinic and pyrrolic configurations. Additionally, the nitrogen concentration varies throughout the carbon fibre, which may suggest that the electrochemical properties also vary throughout the carbon fibre. The knowledge provided by this thesis can lead to future carbon fibre designs with enhanced electrochemical performance for multifunctional applications.
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| 10. |
- Johansen, Marcus, 1994, et al.
(författare)
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Unravelling lithium distribution in carbon fibre electrodes for structural batteries with atom probe tomography
- 2024
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Ingår i: Carbon. - 0008-6223. ; 225
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Tidskriftsartikel (refereegranskat)abstract
- Carbon fibres in structural batteries are multifunctional by acting both as structural reinforcement and as lithium (Li)-ion battery electrode. The relationship between the microstructure and mechanical capabilities of carbon fibres are well established, but much remains unexplored regarding their electrochemical properties. Specifically needed is a nanoscale understanding of how Li atoms distribute and interact in the carbon fibres. Atom probe tomography (APT) is uniquely positioned to provide subnanometre resolution in three dimensions. However, it has previously been hampered by undesirable Li migration during analysis. Here, we show that APT is successfully used to analyse electrochemically cycled polyacrylonitrile-based carbon fibres, through electrostatic shielding by means of conductive coating. We measure ∼1.5 at% Li in the carbon fibres after full delithiation, and thus identify trapped Li to constitute a substantial part of the initial capacity fade. After lithiation, Li accounts for ∼9 at% and according to frequency distribution analysis tend to agglomerate on the atomic scale. With nearest neighbour analysis, Li agglomeration is shown independent of heteroatom dopants such as nitrogen. Thus, the agglomeration is more likely induced by differing accessibility for Li in the crystalline and amorphous domains in the carbon fibre. The method used in this study can inform APT experiments on other type of Li-containing carbon electrodes. The findings of the study can be used to guide design of novel carbon fibres for structural batteries with enhanced electrochemical properties.
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