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Hirt SD, Opitz M, Kappl H, Hägele M, Sous P, Oberschachtsiek B, Sörgel S, Kaßner H, Hoster HE. Attenuating the Polysulfide Shuttle Mechanism by Separator Coating. Chemphyschem 2024:e202300858. [PMID: 38483867 DOI: 10.1002/cphc.202300858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Indexed: 04/10/2024]
Abstract
Lithium-sulfur batteries have a high energy density but lack cycle stability to reach market maturity. This is mainly due to the polysulfide shuttle mechanism, i. e., the leaching of active material from the cathode into the electrolyte and subsequent side reactions. We demonstrate how to attenuate the polysulfide shuttle by magnetron sputtering molybdenum oxysulfide, manganese oxide, and chromium oxide onto microporous polypropylene separators. The morphology of the amorphous coatings was analyzed by SEM and XRD. Electrochemical cyclization quantified how these coatings improved Coulombic efficiency and cycle stability. These tests were conducted in half cells. We compare the different performances of the different coatings with the known chemical and adsorption properties of the respective coating materials.
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Affiliation(s)
- Sebastian Daniel Hirt
- The Hydrogen and fuel cell center (ZBT), Carl-Benz-Straße 201, 47057, Duisburg, Germany
| | - Martin Opitz
- Forschungsinstitut Edelmetalle+Metallchemie (fem), Katharinenstraße 17, 73525, Schwäbisch Gmünd, Germany
| | - Herbert Kappl
- Forschungsinstitut Edelmetalle+Metallchemie (fem), Katharinenstraße 17, 73525, Schwäbisch Gmünd, Germany
| | - Mareike Hägele
- Forschungsinstitut Edelmetalle+Metallchemie (fem), Katharinenstraße 17, 73525, Schwäbisch Gmünd, Germany
| | - Pascal Sous
- The Hydrogen and fuel cell center (ZBT), Carl-Benz-Straße 201, 47057, Duisburg, Germany
| | - Bernd Oberschachtsiek
- The Hydrogen and fuel cell center (ZBT), Carl-Benz-Straße 201, 47057, Duisburg, Germany
| | - Seniz Sörgel
- Forschungsinstitut Edelmetalle+Metallchemie (fem), Katharinenstraße 17, 73525, Schwäbisch Gmünd, Germany
| | - Holger Kaßner
- Forschungsinstitut Edelmetalle+Metallchemie (fem), Katharinenstraße 17, 73525, Schwäbisch Gmünd, Germany
| | - Harry Ernst Hoster
- The Hydrogen and fuel cell center (ZBT), Carl-Benz-Straße 201, 47057, Duisburg, Germany
- Lehrstuhl Energietechnik, University Duisburg-Essen, Lotharstraße 8, 47048, Duisburg, Germany
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Wagner S, Treptow K, Weser S, Drexler M, Sahakalkan S, Eberhardt W, Guenther T, Pruss C, Herkommer A, Zimmermann A. Injection Molding of Encapsulated Diffractive Optical Elements. Micromachines (Basel) 2023; 14:1223. [PMID: 37374806 DOI: 10.3390/mi14061223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 06/02/2023] [Accepted: 06/08/2023] [Indexed: 06/29/2023]
Abstract
Microstructuring techniques, such as laser direct writing, enable the integration of microstructures into conventional polymer lens systems and may be used to generate advanced functionality. Hybrid polymer lenses combining multiple functions such as diffraction and refraction in a single component become possible. In this paper, a process chain to enable encapsulated and aligned optical systems with advanced functionality in a cost-efficient way is presented. Within a surface diameter of 30 mm, diffractive optical microstructures are integrated in an optical system based on two conventional polymer lenses. To ensure precise alignment between the lens surfaces and the microstructure, resist-coated ultra-precision-turned brass substrates are structured via laser direct writing, and the resulting master structures with a height of less than 0.002 mm are replicated into metallic nickel plates via electroforming. The functionality of the lens system is demonstrated through the production of a zero refractive element. This approach provides a cost-efficient and highly accurate method for producing complicated optical systems with integrated alignment and advanced functionality.
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Affiliation(s)
- Stefan Wagner
- Hahn-Schickard, Allmandring 9B, 70569 Stuttgart, Germany
- Institute for Micro Integration (IFM), Faculty 7-Engineering Design, Production Engineering and Automotive Engineering, University of Stuttgart, Allmandring 9B, 70569 Stuttgart, Germany
| | - Kevin Treptow
- Institute for Micro Integration (IFM), Faculty 7-Engineering Design, Production Engineering and Automotive Engineering, University of Stuttgart, Allmandring 9B, 70569 Stuttgart, Germany
| | - Sascha Weser
- Hahn-Schickard, Allmandring 9B, 70569 Stuttgart, Germany
| | - Marc Drexler
- Hahn-Schickard, Allmandring 9B, 70569 Stuttgart, Germany
| | | | | | - Thomas Guenther
- Hahn-Schickard, Allmandring 9B, 70569 Stuttgart, Germany
- Institute for Micro Integration (IFM), Faculty 7-Engineering Design, Production Engineering and Automotive Engineering, University of Stuttgart, Allmandring 9B, 70569 Stuttgart, Germany
| | - Christof Pruss
- Institute for Applied Optics, Pfaffenwaldring 9, 70569 Stuttgart, Germany
| | - Alois Herkommer
- Institute for Applied Optics, Pfaffenwaldring 9, 70569 Stuttgart, Germany
| | - André Zimmermann
- Hahn-Schickard, Allmandring 9B, 70569 Stuttgart, Germany
- Institute for Micro Integration (IFM), Faculty 7-Engineering Design, Production Engineering and Automotive Engineering, University of Stuttgart, Allmandring 9B, 70569 Stuttgart, Germany
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Steinbrenner I, Houdek P, Pollok S, Brandner JM, Daniels R. Influence of the Oil Phase and Topical Formulation on the Wound Healing Ability of a Birch Bark Dry Extract. PLoS One 2016; 11:e0155582. [PMID: 27219110 PMCID: PMC4878794 DOI: 10.1371/journal.pone.0155582] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2015] [Accepted: 05/02/2016] [Indexed: 12/12/2022] Open
Abstract
Triterpenes from the outer bark of birch are known for various pharmacological effects including enhanced wound healing (WH). A birch bark dry extract (TE) obtained by accelerated solvent extraction showed the ability to form oleogels when it is suspended in oils. Consistency of the oleogels and the dissolved amount of triterpenes varies largely with the used oil. Here we wanted to know to what extent different oils and formulations (oleogel versus o/w emulsion) influence WH. Looking at the plain oils, medium-chain triglycerides (MCT) enhanced WH (ca. 1.4-fold), while e.g. castor oil (ca.0.3-fold) or light liquid paraffin (LLP; ca. 0.5-fold) significantly decreased WH. Concerning the respective oleogels, TE-MCT showed no improvement although the solubility of the TE was high. In contrast, the oleogel of sunflower oil which alone showed a slight tendency to impair WH, enhanced WH significantly (ca. 1.6-fold). These results can be explained by release experiments where the release rate of betulin, the main component of TE, from MCT oleogels was significantly lower than from sunflower oil oleogels. LLP impaired WH as plain oil and even though it released betulin comparable to sunflower oil it still results in an overall negative effect of the oleogel on WH. As a further formulation option also surfactant free o/w emulsions were prepared using MCT, sunflower oil and LLP as a nonpolar oil phase. Depending on the preparation method (suspension or oleogel method) the distribution of the TE varied markedly and affected also release kinetics. However, the released betulin was clearly below the values measured with the respective oleogels. Consequently, none of the emulsions showed a significantly positive effect on WH. In conclusion, our data show that the oil used as a vehicle influences wound healing not only by affecting the release of the extract, but also by having its own vehicle effect on wound healing. This is also of importance for other applications where drugs have to be applied in non-polar vehicles because these solvents likely influence the outcome of the experiment substantially.
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Affiliation(s)
- Isabel Steinbrenner
- Department of Pharmaceutical Technology, Eberhard Karls University Tuebingen, Tuebingen, Germany
| | - Pia Houdek
- University Hospital Hamburg Eppendorf, Department of Dermatology & Venerology, Hamburg, Germany
| | - Simone Pollok
- University Hospital Hamburg Eppendorf, Department of Dermatology & Venerology, Hamburg, Germany
| | - Johanna M. Brandner
- University Hospital Hamburg Eppendorf, Department of Dermatology & Venerology, Hamburg, Germany
| | - Rolf Daniels
- Department of Pharmaceutical Technology, Eberhard Karls University Tuebingen, Tuebingen, Germany
- * E-mail:
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