| 1. |
- Esser, Birgit, et al.
(författare)
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A perspective on organic electrode materials and technologies for next generation batteries
- 2021
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Ingår i: Journal of Power Sources. - : Elsevier. - 0378-7753 .- 1873-2755. ; 482
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Tidskriftsartikel (refereegranskat)abstract
- In this perspective article, we review some of the most recent advances in the emerging field of organic materials as the electroactive component in solid electrodes for batteries. These comprise, but are not limited to, organometallic salts, small molecular systems, redox-active macromolecules, as well as hybrid formulations with inorganic electrode constituents. The materials are first scrutinized in terms of their general electrochemical performance and most apparent challenges, while an outlook is then made into how to best utilize them in battery electrodes and in all-organic cells. An insight into the fundamental structural-dynamic properties of these compounds, not least explored through a range of modelling and characterization techniques, is also given to complement the experimental advances. The major advantages of these materials as compared to competing technologies are most likely their potentially low environmental impact and general sustainability, which forms the context of this summary of the research field and corresponding technology area.
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| 2. |
- Han, Ning, et al.
(författare)
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Achieving Efficient Electrocatalytic Oxygen Evolution in Acidic Media on Yttrium Ruthenate Pyrochlore through Cobalt Incorporation
- 2023
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Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 33:20
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Tidskriftsartikel (refereegranskat)abstract
- The development of electrocatalysts for the oxygen evolution reaction (OER) especially in acidic media remains the major challenge that still requires significant advances, both in material design and mechanistic exploration. In this study, the incorporation of cobalt in Y2-xCoxRu2O7−δ results in an ultrahigh OER activity because of the charge redistribution at eg orbitals between Ru and Co atoms. The Y1.75Co0.25Ru2O7−δ electrocatalyst exhibits an extremely small overpotential of 275 mV in 0.5 m H2SO4 at the current density of 10 mA cm−2, which is smaller than that of parent Y2Ru2O7−δ (360 mV) and commercial RuO2 (286 mV) catalysts. The systematic investigation of the composition related to OER activity shows that the Co substitution will also bring other effective changes, such as reducing the bandgap, and creating oxygen vacancies, which result in fast OER charge transfer. Meanwhile, the strengthening of the bond hybridization between the d orbitals of metal (Y and Ru) and the 2p orbitals of O will intrinsically enhance the chemical stability. Finally, theoretical calculations indicate that cobalt substitution reduces the theoretical overpotential both through an adsorbate evolution mechanism and a lattice oxygen-mediated mechanism.
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| 3. |
- Liu, Xuelian, et al.
(författare)
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Surface, Structural, and Electrochemical Analysis of High-Voltage Spinel Cathode LiNi0.5Mn1.5O4 Evolution Upon Ambient Storage Conditions
- 2023
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Ingår i: Journal of the Electrochemical Society. - : Electrochemical Society. - 0013-4651 .- 1945-7111. ; 170:10
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Tidskriftsartikel (refereegranskat)abstract
- Spinel LiNi0.5Mn1.5O4 as one of the high-energy positive electrode materials for next generation Li-ion batteries has attracted significant interest due to its economic and environmental advantages. However, the sensitivity of this type of material upon short to long term ambient storage conditions and the impact on the electrochemical performances remains poorly explored. Nevertheless, this remains an important aspect for practical large-scale synthesis, storage and utilization. Herein, we study and compare the evolution of surface chemistry, bulk crystal structure and elemental content evolution and distribution of LiNi0.5Mn1.5O4 using a variety of characterization techniques including XPS and STEM-EDS-EELS, as well as electrochemical analysis. We show that Mn species dominate the outer surface (0–5 nm), while Ni and Li are preferentially located further away and in the bulk. The studied LiNi0.5Mn1.5O4 material is found to be stable, with minor changes in surface or bulk characteristics detected, even after 12 months of storage under ambient air conditions. The low surface reactivity to air also accounts for the minor changes to the electrochemical performance of the air-exposed LiNi0.5Mn1.5O4, compared to the pristine material. This study provides guidance for the appropriate storage, handling and processing of this high-performance cathode material.
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| 4. |
- Marto, João Pedro, et al.
(författare)
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Safety and Outcome of Revascularization Treatment in Patients With Acute Ischemic Stroke and COVID-19: The Global COVID-19 Stroke Registry.
- 2023
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Ingår i: Neurology. - 1526-632X. ; 100:7
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Tidskriftsartikel (refereegranskat)abstract
- COVID-19-related inflammation, endothelial dysfunction, and coagulopathy may increase the bleeding risk and lower the efficacy of revascularization treatments in patients with acute ischemic stroke (AIS). We aimed to evaluate the safety and outcomes of revascularization treatments in patients with AIS and COVID-19.This was a retrospective multicenter cohort study of consecutive patients with AIS receiving intravenous thrombolysis (IVT) and/or endovascular treatment (EVT) between March 2020 and June 2021 tested for severe acute respiratory syndrome coronavirus 2 infection. With a doubly robust model combining propensity score weighting and multivariate regression, we studied the association of COVID-19 with intracranial bleeding complications and clinical outcomes. Subgroup analyses were performed according to treatment groups (IVT-only and EVT).Of a total of 15,128 included patients from 105 centers, 853 (5.6%) were diagnosed with COVID-19; of those, 5,848 (38.7%) patients received IVT-only and 9,280 (61.3%) EVT (with or without IVT). Patients with COVID-19 had a higher rate of symptomatic intracerebral hemorrhage (SICH) (adjusted OR 1.53; 95% CI 1.16-2.01), symptomatic subarachnoid hemorrhage (SSAH) (OR 1.80; 95% CI 1.20-2.69), SICH and/or SSAH combined (OR 1.56; 95% CI 1.23-1.99), 24-hour mortality (OR 2.47; 95% CI 1.58-3.86), and 3-month mortality (OR 1.88; 95% CI 1.52-2.33). Patients with COVID-19 also had an unfavorable shift in the distribution of the modified Rankin score at 3 months (OR 1.42; 95% CI 1.26-1.60).Patients with AIS and COVID-19 showed higher rates of intracranial bleeding complications and worse clinical outcomes after revascularization treatments than contemporaneous non-COVID-19 patients receiving treatment. Current available data do not allow direct conclusions to be drawn on the effectiveness of revascularization treatments in patients with COVID-19 or to establish different treatment recommendations in this subgroup of patients with ischemic stroke. Our findings can be taken into consideration for treatment decisions, patient monitoring, and establishing prognosis.The study was registered under ClinicalTrials.gov identifier NCT04895462.
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| 5. |
- Zhang, Wei, et al.
(författare)
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Balancing Adsorption, Catalysis, and Desorption in Cathode Catalyst For Li–S Batteries
- 2023
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Ingår i: Advanced Energy Materials. - 1614-6832 .- 1614-6840. ; 13:43
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Tidskriftsartikel (refereegranskat)abstract
- The complicated electrochemical catalytic conversion process of polysulfides in metal–sulfur batteries involves three steps: adsorption, catalysis, and desorption process. Even as huge efforts are made for the understanding of the separate steps (especially for the adsorption and catalysis process), research focusing on the entire process is still scarce. Herein, a series of cobalt phosphides (CoP, CoP2, and CoP3) is employed with identical hollow morphology as model electrocatalysts to investigate the significance of the desorption process and discuss the balancing among the adsorption, catalysis, and desorption of lithium polysulfides (LiPSs). The experimental data demonstrate that, compared to CoP and CoP3, CoP2 exhibits moderate adsorption of LiPSs, which enhances the reduction kinetics of S8 to Li2S and regulates the desorption of short-chain LiPSs. Theoretical calculations further confirm that CoP2 with moderate adsorption of LiPSs exhibits better redox kinetics of LiPSs compared to CoP and CoP3. Moderate adsorption enables the CoP2-based sulfur cathode to deliver excellent stability with 86% capacity retention (2.6 and 2.0 times higher than CoP and CoP3, respectively) over 1000 cycles at 1 C. All these results indicate that in the adsorption-catalysis-desorption chain for LiPSs, all steps need to be considered rather than just focusing on one step of the process.
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