| 1. |
- Chien, Yu-Chuan, 1990-, et al.
(författare)
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Impact of Compression on the Electrochemical Performance of the Sulfur/Carbon Composite Electrode in Lithium-Sulfur Batteries
- 2022
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Ingår i: Batteries & Supercaps. - : Wiley-VCH Verlagsgesellschaft. - 2566-6223. ; 5:7
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Tidskriftsartikel (refereegranskat)abstract
- While lithium-sulfur batteries theoretically have both high gravimetric specific energy and volumetric energy density, only its specific energy has been experimentally demonstrated to surpass that of the state-of-the-art lithium-ion systems at cell level. One major reason for the unrealized energy density is the low capacity density of the highly porous sulfur/carbon composite as the positive electrode. In this work, mechanical compression at elevated temperature is demonstrated to be an effective method to increase the capacity density of the electrode by at least 90 % and moreover extends its cycle life. Distinct impacts of compression on the resistance profiles of electrodes with different thickness are investigated by tortuosity factors derived from both electrochemical impedance spectroscopy, X-ray computed tomography and kinetic analysis based on operando X-ray diffraction. The results highlights the importance of a homogeneous electrode structure highlight lithium-sulfur system.
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| 2. |
- Hernández, Guiomar, et al.
(författare)
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Fluorine-Free Electrolytes for Lithium and Sodium Batteries
- 2022
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Ingår i: Batteries & Supercaps. - : John Wiley & Sons. - 2566-6223. ; 5:6
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Forskningsöversikt (refereegranskat)abstract
- Fluorinated components in the form of salts, solvents and/or additives are a staple of electrolytes for high-performance Li- and Na-ion batteries, but this comes at a cost. Issues like potential toxicity, corrosivity and environmental concerns have sparked interest in fluorine-free alternatives. Of course, these electrolytes should be able to deliver performance that is on par with the electrolytes being in use today in commercial batteries. This begs the question: Are we there yet? This review outlines why fluorine is regarded as an essential component in battery electrolytes, along with the numerous problems it causes and possible strategies to eliminate it from Li- and Na-ion battery electrolytes. The examples provided demonstrate the possibilities of creating fully fluorine-free electrolytes with similar performance as their fluorinated counterparts, but also that there is still a lot of room for improvement, not least in terms of optimizing the fluorine-free systems independently of their fluorinated predecessors.
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| 3. |
- Karlsmo, Martin, 1995, et al.
(författare)
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Sustainability and Technical Performance of An All-Organic Aqueous Sodium-Ion Hybrid Supercapacitor
- 2022
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Ingår i: Batteries and Supercaps. - : Wiley. - 2566-6223.
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Tidskriftsartikel (refereegranskat)abstract
- Development of all-organic aqueous energy storage devices (ESDs) is a promising pathway towards meeting the needs of technically medium/low-demanding electrical applications. Such ESDs should favour low cost, low environmental impact, and safety, and thereby complement more expensive, high voltage, and energy/power dense ESDs such as lithium-ion batteries. Herein, we set out to assemble all-organic aqueous Na-ion hybrid supercapacitors, exclusively using commercial materials, with the aim to provide a truly sustainable and lowcost ESD. Overall, the created ESD delivers adequate technical performance in terms of capacity retention, Coulombic efficiency, energy efficiency, and energy/power density. Finally, we apply a straight-forward and qualitative biodegradability method to the ESD.
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| 4. |
- Mathew, Alma, et al.
(författare)
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Understanding the Capacity Fade in Polyacrylonitrile Binder-based LiNi0.5Mn1.5O4 Cells
- 2022
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Ingår i: Batteries & Supercaps. - : John Wiley & Sons. - 2566-6223. ; 5:12
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Binders are electrochemically inactive components that have a crucial impact in battery ageing although being present in only small amounts, typically 1?3?% w/w in commercial products. The electrochemical performance of a battery can be tailored via these inactive materials by optimizing the electrode integrity and surface chemistry. Polyacrylonitrile (PAN) for LiNi0.5Mn1.5O4 (LNMO) half-cells is here investigated as a binder material to enable a stable electrode-electrolyte interface. Despite being previously described in literature as an oxidatively stable polymer, it is shown that PAN degrades and develops resistive layers within the LNMO cathode. We demonstrate continuous internal resistance increase in LNMO-based cells during battery operation using intermittent current interruption (ICI) technique. Through a combination of on-line electrochemical mass spectrometry (OEMS) and X-ray photoelectron spectroscopy (XPS) characterization techniques, the degradation products can be identified as solid on the LNMO electrode surface, and no excessive gas formation seen. The increased resistance and parasitic processes are correlated to side-reactions of the PAN, possibly intramolecular cyclization, which can be identified as the main cause of the comparatively fast capacity fade.
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| 5. |
- Wu, Liang-Ting, et al.
(författare)
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Prediction of SEI Formation in All-Solid-State Batteries : Computational Insights from PCL-based Polymer Electrolyte Decomposition on Lithium-Metal
- 2022
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Ingår i: Batteries & Supercaps. - : John Wiley & Sons. - 2566-6223. ; 5:9
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Tidskriftsartikel (refereegranskat)abstract
- Identifying the solid electrolyte interphase (SEI) components in all-solid-state lithium batteries (ASSLBs) is essential when developing strategies for improving this battery technology. However, a comprehensive understanding of the interfacial stability and decomposition reactions of solid polymer electrolyte with lithium metal anode remains a challenge, not least outside the dominating poly(ethylene oxide)-based materials. Here, we report the reactivity of an electrolyte system composed of a polyester (poly-epsilon-caprolactone, PCL) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt on Li (100) surface, and the subsequent SEI formation, using ab initio molecular dynamics (AIMD) simulations. The step-by-step electrolyte decomposition on the anode surface is monitored, and the resultant major SEI components are analyzed by Bader charges to correlate with X-ray photoelectron (XPS) signal. The presence of PCL at the Li surface promotes a rapid initial reduction of LiTFSI salt via cleavage of S-N and C-S bonds, and its complete dissociation and formation of major SEI components such as LiF, Li2O, Li2S, and C-containing species. Furthermore, a computational analysis of relevant XPS spectra is performed to support the degradation compounds.
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| 6. |
- Zhang, Leiting, et al.
(författare)
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Reactivity of TiS2 Anode towards Electrolytes in Aqueous Li‐ion Batteries
- 2022
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Ingår i: Batteries & Supercaps. - : John Wiley & Sons. - 2566-6223. ; 5:12
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Tidskriftsartikel (refereegranskat)abstract
- Aqueous rechargeable batteries are appealing alternatives for large-scale energy storage. Reversible cycling of high-energy aqueous batteries has been showcased using highly concentrated aqueous electrolytes, which lead to a significantly suppressed water activity and formation of a stable solid-electrolyte interphase (SEI). However, the high salt concentration inevitably raises the cost and compromises the environmental sustainability. Herein, we use layered TiS2 as a model anode to explore the feasibility of cycling aqueous cells in dilute electrolytes. By coupling three-electrode cycling data with online electrochemical mass spectrometry measurements, we depict the potential-dependent gas evolution from the cell in the absence of a stable SEI. We offer a comprehensive mechanistic understanding of the complex interfacial chemistry in dilute electrolytes, taking into account material reactivity and interfacial compatibility. Design strategies and research directions of layered-type electrodes for sustainable aqueous batteries with dilute electrolytes are recommended, based on the scientific discovery presented in this work.
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| 7. |
- Zheng, Wei, et al.
(författare)
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MXene//MnO2 Asymmetric Supercapacitors with High Voltages and High Energy Densities
- 2022
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Ingår i: Batteries & Supercaps. - : Wiley-V C H Verlag GMBH. - 2566-6223. ; 5:10
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Tidskriftsartikel (refereegranskat)abstract
- Aqueous asymmetric supercapacitors (AASCs) can have high voltages and high energy densities. However, the rational design of AASCs with proper negative and positive electrodes remains a challenge. Herein, we report on an AASC using Mo1.33CTz MXene films as the negative electrode, and tetramethylammonium cation intercalated birnessite (TMA(+)-MnO2) films as the positive electrode in a 21 mol kg(-1) lithium bis(trifluoromethanesulphonyl)imide (LiTFSI) electrolyte. Benefiting from a high, stable voltage of 2.5 V, an energy density of 86.5 Wh L-1 at 2 mV s(-1) and a power density of 10.3 kW L-1 at 1 Vs(-1) were achieved. The cells also exhibit excellent cycling stability (>98% after 1,0000 cycles at 100 mV s(-1)) and a 51.1 % voltage retention after 10 h. This good performance is attributed to the high stable potential window and high volumetric capacitances of both Mo1.33CTz and TMA(+)-MnO2 electrodes in highly concentrated electrolytes. This work provides a roadmap for developing high performance AASCs with high voltages and high energy/power densities, with relatively slow self-discharge rates.
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