Habilitationen/ Promotionen/ Fachpresse

2024

2021

  • Jahrbuch Oberflächentechnik Band 77 (2021): David Glück, Mathias Fritz, Indira Käpplinger, Andreas Bund, "Nickel-Ti3SiC2-Dispersionsbeschictungen", Eugen G. Leuze Verlag KG, Bad Saulgau, ISBN 978-3-87480-369-4, pp. 117-125

2019

  • DGM-dIALOG Vol 3(2019) S16-21
    "Elektrochemische Oberflächentechnik"
    R. Böttcher, A. Endrikat, T. Engemann, M. Fritz, V. Gruia, S. Hesamedini, A. Ispas, M. Leimbach, U. Schmidt, R. Sottor und A. Bund

Publikationen des Fachgebietes "Elektrochemie und Galvanotechnik"

Anzahl der Treffer: 587
Erstellt: Fri, 12 Apr 2024 23:02:27 +0200 in 0.0982 sec


Shekhawat, Deepshikha; Sindhani, Kashish; Raheja, Vishal Amarbhai; Baloochi, Mostafa; Isaac, Nishchay Angel; Pezoldt, Jörg
Modelling reaction transfer velocities in disconnected compact heterogeneous multilayer reactive material systems. - In: MRS advances, ISSN 2059-8521, Bd. 0 (2024), 0, S. 1-6

The tuning of the self-propagating reaction is studied theoretically by introducing a non-reactive material between two reactive material elements. For the study, the Ni/Al bilayer system was chosen. The Ni/Al elements were placed on a silicon wafer covered with a 1-µm-thick silicon dioxide. The spaces between the multilayer reactive material elements were filled with different non-reactive materials covering a wide range of thermal properties. On top of this heterogeneous layer, a 1-µm-thick sealing layer was placed consisting of the filler material. The carried out two-dimensional simulations demonstrated that embedding material allows to scale the ignition transfer time and the heat propagation velocity. For example, for a transfer length of 1 µm, the ignition time can be tuned from nano- to microseconds. Consequently, in contrast to previous results embedding materials allow scaling the properties of the self-propagating reaction in heterogeneous reactive material systems.



https://doi.org/10.1557/s43580-024-00822-3
Omar, Nurul Amanina Binti; Köster, Frank; Hahn, Frank; Bund, Andreas
Hardness and tribological behaviour of annealed electroless nickel phosphorus composite layers with incorporated boron particles. - In: Surface and coatings technology, ISSN 1879-3347, Bd. 476 (2024), 130261, S. 1-17

In this study, a possible alternative to hard chromium coatings is investigated. Amorphous boron particles have been incorporated in electroless nickel‑phosphorus (NiP) deposits, yielding a dispersion coating. The distribution of the particles is homogenous and the maximum mass fraction of particles embedded in the coating is 6.2 ± 0.2 wt%. Measurements of the zeta potential and particle size of amorphous boron particles in a diluted electrolyte showed that the particles withstood agglomeration until 120 days. Primary and secondary hardness maxima are observed after thermal annealing at 400 ˚C and 860 ˚C due to the formation of nickel phosphide, nickel boride and nickel boride phosphide phases. X-ray diffractometry shows an increase in nickel and nickel phosphide crystal size at 400 ˚C before levelling off at 600 ˚C. The annealing duration should be kept between 30 and 60 min for optimal hardness. The wear resistance increases when the coating is annealed at 400 ˚C. DSC measurements on nickel phosphorus incorporated with boron particles, Ni-P-B, bulk material with P-content (9.6 ± 0,6 wt%) and B-content (4.5 ± 0.8 wt%) showed that the solidus line lies at 926 ˚C, which is why a maximum annealing temperature of 860 ˚C was chosen to avoid melting of the material. The relative texture and phase coefficients, RTC and RPC, showed that the nickel phase is preferred in the NiP system at 400 ˚C and 600 ˚C while the Ni3P phase is preferred in the Ni-P-B system at the same annealing temperature. REM and EDX area analyses are used to show the areal distribution of nickel, phosphorus, and boron before and after the annealing process along the thickness of the coating. A diffusion layer between substrate and coating that contains iron nickel boride and iron nickel phosphide lamellar structure is observed.



https://doi.org/10.1016/j.surfcoat.2023.130261
Supreeti, Shraddha; Fischer, Michael; Fritz, Mathias; Müller, Jens
High-resolution patterning on LTCC by transfer of photolithography-based metallic microstructures. - In: International journal of applied ceramic technology, ISSN 1744-7402, Bd. 21 (2024), 2, S. 1180-1190

The growing applications and constant miniaturization of electronic devices and of low-temperature co-fired ceramics (LTCC) in various fields, such as aviation, telecommunications, automotive, satellite communications, and military, have led to an increase in the demand for LTCC. Such prospects arise due to the continuous scaling down of components and high-density interconnection in electronics packaging. This paper reports a technique for the transfer of high-resolution microstructures from silicon substrates to LTCC. In this method, gold and copper patterns were formed by photolithography, electrodeposition, and residual layer stripping on silicon substrate. Lithography provides the opportunity to create and transfer complex patterns for use in several different applications and electroplating enables the use of pure metal for excellent electrical properties. The developed structures were transferred onto a top layer of LTCC tape using hot embossing. Then, the subsequent layers were stacked, laminated, and sintered. A resolution of 1.5 μm after free sintering and 4.5 μm after pressure-assisted sintering was achieved. This distinctive method can be useful for several applications requiring high-resolution and superior electrical properties.



https://doi.org/10.1111/ijac.14569
Najeeb, Mussab; Schwalbe, Ulf; Herget, Mathias
Improved approach for online monitoring of second life lithium-ion batteries to optimize the performance in stationary storage systems. - In: IEEE Xplore digital library, ISSN 2473-2001, (2023), insges. 6 S.

Monitoring lithium-ion batteries in their second life is of great importance when using them in stationary storage systems for grid support or in any other energy system, due to the expected different behavior and operational conditions in their second life compared to their first life. The idea of this study based on the fact that each estimation method has its advantages and drawbacks depending on the application in which the batteries will be used, and that monitoring batteries in their second life required to be integrated with the battery management system to balance cells, optimize performance, and prevent overheating. The contribution of our study can be summarized in the integration of specific methods, aiming to benefit from most of their advantages and neutralizing their drawbacks as much as possible to provide more accurate and reliable online monitoring of batteries. The combination presented in this study, consisting, for state of charge estimation, of an artificial neural network and an Unscented Kalman Filter with adjusting the filtering process using Coulomb counting, and Kalman Filter for state of health estimation, showed much better reliability and accuracy than if each method was used alone. This combination has been trained and adjusted using empirical data of second-life batteries, extracted from used electric vehicle battery bank, to obtain the best possible performance, considering the specificity of these batteries in terms of operating voltage range, lower current ratio, and other parameters.



https://doi.org/10.1109/IREC59750.2023.10389283
Kurniawan, Mario; Bund, Andreas
Photoelectrochemical water splitting with cuprous oxide. - In: Galvanotechnik, ISSN 0016-4232, Bd. 114 (2023), 11, S. 1396-1398

Enhancing the performance through the implementation of porous structures - an innovative and cost-effective fabrication technique that relies solely on electrodeposition.



Engemann, Thomas; Ispas, Adriana; Bund, Andreas
Electrochemical reduction of tantalum and titanium halides in 1-butyl-1-methylpyrrolidinium bis (trifluoromethyl-sulfonyl)imide and 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate ionic liquids. - In: Journal of solid state electrochemistry, ISSN 1433-0768, Bd. 0 (2023), 0, insges. 14 S.

The electrodeposition of tantalum-titanium–based films using different tantalum and titanium halides was investigated in two ionic liquids, namely, 1-butyl-1-methylpyrrolidinium bis (trifluoromethyl-sulfonyl)imide ([BMP][TFSI]) and 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate ([BMP][OTf]). Cyclic voltammetry was used to analyse the electrochemistry of the electrolytes and potentiostatic deposition was performed to evaluate the feasibility of electrodepositing tantalum-titanium–based layers. Both the metal salts and the ionic liquid influenced the electrochemical reduction of the tantalum and titanium halides significantly. While titanium halides considerably retarded the reduction of tantalum pentahalides and inhibited electrodeposition in many electrolytes, an electrolyte composition from which tantalum and titanium-containing layers could be deposited was identified. Specifically, in TaBr5 and TiBr4 in [BMP][TFSI], TiBr4 did not inhibit the deposition of tantalum and titanium was co-deposited itself by a three-step reduction mechanism as confirmed by cyclic voltammetry and energy-dispersive X-ray spectroscopy. Furthermore, [BMP][TFSI] led to smoother and more compact deposits.



https://doi.org/10.1007/s10008-023-05773-7
Witt, Michael; Papmahl, Eric; Genov, Ivan; Dimitrova, Anna; Gabryelczyk, Agnieszka; Krischok, Stefan; Lota, Grzegorz; Ivanov, Svetlozar
In-situ electrogravimetric detection of the cathodic process during the galvanic coupling between lithium and copper. - In: Electrochimica acta, ISSN 1873-3859, Bd. 463 (2023), 142853

With the development of the energy system transformation the quality and efficiency of the rechargeable batteries, particularly the Li ion technology, gain major importance. In spite of the enormous advances, along with many other technological challenges corrosion of the metallic battery parts is often a difficult obstacle for producers and researchers. Li-metal batteries and especially the “anode-free” battery concept could significantly increase the energy density. However, contact corrosion of the Li anode, can occur in this cell configuration since there is a high probability of a three-phase contact between Li-metal, current collector and electrolyte, a condition triggering an intensive Li corrosion. In this work, a new in-situ analytical methodology based on combining electrochemical (ZRA) and microgravimetric (QCM) techniques is proposed for studying the galvanic corrosion. The applicability of this approach is explored in three different electrolyte compositions. Beside the analysis of the conventional electrochemical parameters an in-situ gravimetric detection of the deposited electrolyte decomposition products on the cathode surface is demonstrated. Adsorbed polymer layer on the Cu surface is applied for cathodic inhibition of the galvanic corrosion process, which is studied by means of the novel ZRA-QCM approach.



https://doi.org/10.1016/j.electacta.2023.142853
Moazezi, Alireza; Henne, Stefan Georg; Fritz, Mathias
Improvement of corrosion behavior of chromium(III) coatings. - In: Galvanotechnik, ISSN 0016-4232, Bd. 114 (2023), 3, S. 311-319

Nickel/Chromium electroplating is widely used in engineering applications, especially for decorative thin film plating, abrasion resistance, and corrosion protection [1]. Depositions of metallic chromium from trivalent chromium electrolytes show a lower corrosion resistance than those from hexavalent baths. Therefore, this research work investigated the effect of anodic post-treatment on the corrosion behavior of conventional and micro-cracked chromium (III) based coatings with a series of evaluation methods for corrosion resistance. While the corrosion tests indicated reduced corrosion rates for conventional chromium (III) based coatings, no improvement was observed for micro-cracked chromium coatings.



Mejia Chueca, Maria del Carmen; Graske, Marcus; Winter, Andreas; Baumer, Christoph; Stich, Michael; Mattea, Carlos; Ispas, Adriana; Isaac, Nishchay Angel; Schaaf, Peter; Stapf, Siegfried; Jacobs, Heiko O.; Bund, Andreas
Electrodeposition of reactive aluminum-nickel coatings in an AlCl3:[EMIm]Cl ionic liquid containing nickel nanoparticles. - In: Journal of the Electrochemical Society, ISSN 1945-7111, Bd. 170 (2023), 7, 072504

The electrodeposition of aluminum-nickel coatings was performed by pulsed direct current in the ionic liquid (IL) 1.5:1 AlCl3:EMIm]Cl containing nickel nanoparticles (Ni NPs), for reactive dispersion coating application. Several electrochemical and characterization techniques were used to shed more light on the mechanism of Ni particle incorporation into the Al matrix. Thus, particle incorporation at the early stage of the deposition would mainly take place via particle adsorption at the substrate. However, as the thickness of the coating increases, it seems that the main mechanism for particle incorporation is via the reduction of ions adsorbed at the particles surface. Although a considerable high incorporation of Ni NPs has been achieved from the IL containing the highest concentration of Ni NPs (i.e. ∼33 wt% from a 20 g/L of Ni NPs bath), a high concentration of NPs in the IL resulted having a negative effect in terms of quality of the coatings, due to solidification of the electrolyte in a poorly conductive compound. Moreover, almost equivalent amounts of Ni and Al (Ni ∼45 wt.%and Al ∼44 wt.%) have been detected in some areas of the coatings. Such a layer composition would be desired for the targeted application.



https://doi.org/10.1149/1945-7111/ace382
Böttcher, René; Mai, Sebastian; Borisenko, Natalia; Ispas, Adriana; Bund, Andreas; Endres, Frank
A Raman study on the speciation of different metal ions in an AlCl3-based ionic liquid. - In: Journal of the Electrochemical Society, ISSN 1945-7111, Bd. 170 (2023), 7, p072503

The speciation of Cr, Zn and Sn in AlCl3/1-ethyl-3-methylimidazolium chloride containing CrCl2, ZnCl2 and SnCl2, respectively, has been studied by cyclic voltammetry (CV), Raman spectroscopy and density functional theory (DFT) calculations. Addition of the respective metal salt causes the current waves in the CV to decrease, indicating a reaction of the metal salts with Al2Cl7−. Compared to the neat electrolyte, the Raman peaks of Al2Cl7− decrease while the AlCl4− peak increases in intensity, broadens and shifts towards lower wavenumbers. Calculated wavenumbers of metal complexes [Me(AlCl4)3]− reflect these observations. DFT calculations of the Gibbs free energies of formation, solvation and reaction support the formation of the proposed complexes. The central ions are coordinated by three bidentate AlCl4− ligands that are arranged planar-trigonally. Due to the occupied Sn-5s orbital, repulsive forces cause a trigonal-pyramidal geometry in case of the Sn complex. Based on the similarities in the experimental observations and the orbital configuration of Zn2+ compared to Cr2+, the spontaneous formation of the species [Cr(AlCl4)3]− can be assumed.



https://doi.org/10.1149/1945-7111/ace383