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The selection of an appropriate cathode active material is important for operation performance and production of high-performance lithium-ion batteries. Promising candidates are nickel-rich layered oxides like LiNi$_x$Co$_y$Mn$_z$O$_2$ (NCM, x+y+z=1) with nickel contents of ‘x’ ≥ 0.8, characterized by high electrode potential and specific capacity. However, these materials are associated with capacity fading due to their high sensitivity to moisture. Herein, two different polycrystalline NCM materials with nickel contents of 0.81 ≤ ‘x’ ≤ 0.83 and protective surface coatings are processed in dry-room atmosphere (dew point of supply air T$_D$ ≈ −65 °C) at lab scale including the slurry preparation and coating procedure. In comparison, cathodes are produced in ambient atmosphere and both variants are tested in coin cells. Moreover, processing at pilot scale in ambient atmosphere is realized successfully by continuous coating and drying of the cathodes. Relevant electrode properties such as adhesion strength, specific electrical resistance, and pore-size distribution for the individual process steps are determined, as well as the moisture uptake during calendering. Furthermore, rate capability and cycling stability are investigated in pouch cells, wherein initial specific discharge capacities of up to 190 mAh g$^{−1}$ (with regard to the cathode material mass) are achieved at 0.2C.

A complex interaction between the process design and the properties of carbon black (CB) during dry mixing of cathode material influences the microstructure and thus the performance of the Li-ion battery. The description of these interactions by means of a coupling of the mixing process simulation and the fragmentation of CB is the focus of this work. The discrete element method provides information about the frequency and intensity of the stress. The change of the CB size distribution is done by the population balance equation. The material strength as well as the fracture behavior are represented with simple models. The calibration of the model parameters is performed using the Nelder–Mead algorithm. The calibrated models provide good agreement with the measurements of the size distributions from experimental investigations. Transfer of the calibrated parameters to other process settings is possible and provides good agreement in some cases. Recalibration of the fracture behavior improves the accuracy of the model so that it can be used as a predictive tool.

An ontology for the structured storage, retrieval, and analysis of data on lithium-ion battery materials and electrode-to-cell production is presented. It provides a logical structure that is mapped onto a digital architecture and used to visualize, correlate, and make predictions in battery production, research, and development. Materials and processes are specified using a predetermined terminology; a chain of unit processes (steps) connects raw materials and products (items) of battery cell production. The ontology enables the attachment of analytical methods (characterization methods) to items. Workshops and interviews with experts in battery materials and production processes are conducted to ensure that the structure is conformable both for industrial-scale and laboratory-scale data generation and implementation. Raw materials and intermediate products are identified and defined for all steps to the final battery cell. Steps and items are defined based on current standard materials and process chains using terms that are in common use. Alternative structures and the connection of the ontology to other existing ontologies are discussed. The contribution provides a pragmatic, accessible way to unify the storage of materials-oriented lithium-ion battery production data. It aids the linkage of such data with domain knowledge and the automation of data analysis in production and research.

In recent years, the field of Artificial Intelligence (AI) is experiencing a boom, caused by recent breakthroughs in computing power, AI techniques, and software architectures. Among the many fields being impacted by this paradigm shift, process engineering has experienced the benefits caused by AI. However, the published methods and applications in process engineering are diverse, and there is still much unexploited potential. Herein, the goal of providing a systematic overview of the current state of AI and its applications in process engineering is discussed. Current applications are described and classified according to a broader systematic. Current techniques, types of AI as well as pre- and postprocessing will be examined similarly and assigned to the previously discussed applications. Given the importance of mechanistic models in process engineering as opposed to the pure black box nature of most of AI, reverse engineering strategies as well as hybrid modeling will be highlighted. Furthermore, a holistic strategy will be formulated for the application of the current state of AI in process engineering.

This study presents an approach to scale up wet fine grinding processes of organic particles using stirred media mills. The process transfer is based on the calculation of grinding-relevant energy, which is transferred to the product by a model theory derived from mill-related values, especially geometric aspects. Its application was demonstrated by experimental work with two organic products, which were ground with different sizes and geometries of mills reaching from 20 to 900 mL grinding chamber volume under variation of process parameters.

The application of orodispersible films (ODFs) as carrier for drug nanoparticles was discovered a few years ago. Poorly water-soluble drugs are milled to nanosuspensions to improve their bioavailability. During the manufacturing process they are embedded into a polymer matrix or loaded on the surface of drug-free ODF templates. The particle size of the particles released from the ODF was measured when redispersed in water. A preservation of the drug particle sizes could be achieved for both investigated ODF types when an adequate amount of matrix material is added to prevent agglomeration during the drying process.

The yeast Saccharomyces cerevisiae and the microalga Chlorella vulgaris were mechanically characterized using single-cell compression experiments. Micromechanical cell characteristics could be calculated directly from the force displacement data. The mechanical properties of the cell wall were determined with different analytical models because the intrinsic parameters of the cell wall cannot be measured directly. As expected, the Young's moduli obtained from the cellular model and the cell wall model differ by two orders of magnitude. Although yeast and algal cells need similar forces to get disrupted, the bursting deformation and bursting energy of the algal cells are about two times smaller. Based on the dry biomass, the energy for cell breakage of C. vulgaris is about six times higher than that of S. cerevisiae. Finally, the tensile strength of the cell wall was calculated.

Planetenkugelmuhlen sind aufgrund ihrer einfachen Handhabung und ihrer Eigenschaften, wie z. B. hohe Energiedichten, niedrige Anschaffungskosten und gute Reproduzierbarkeit der Ergebnisse, typische Muhlen fur den Laborbetrieb. Obwohl Planetenkugelmuhlen bereits seit vielen Jahren eingesetzt werden, sind die Parametereinflusse auf die Zerkleinerung noch nicht ausreichend verstanden. In dieser Arbeit wird der Einfluss verschiedener Prozessparameter auf die Trockenzerkleinerung in Planetenkugelmuhlen anhand der Zerkleinerung von Aluminiumoxid aufgezeigt. Eine empirische Parameterstudie zur Wahl gunstiger Betriebsparameter wird prasentiert, mit deren Hilfe ein Prozessmodell entwickelt werden soll.

Heat transfer within lithium-ion-battery electrodes constitutes an important issue regarding not only battery performance but also safety aspects. The objective of this study is to gain insight into the thermal behavior of particles forming lithium-ion electrodes to understand the effect of microstructural parameters on heat conduction and, ultimately, improve electrode design. To this end, a discrete element method (DEM) approach is proposed in which a contact model is included. Thus, individual particles are modelled within the electrode and their temperature values are tracked just after the copper substrate, on which the particles are coated, is heated from 273 to 350 K. Furthermore, by adjusting numerous simulations with different structural parameters, namely porosity, particle size, and electrode thickness, the effect of these parameters on the heating rate is investigated.

Polymere Nanokomposite erfahren heutzutage zunehmende Bedeutung fur die Erzeugung funktioneller Beschichtungen. Zu diesem Zweck werden masgeschneiderte modifizierte Nanopartikel in eine Harzmatrix eingebracht und die Eigenschaften einer so erzeugten Beschichtung wesentlich verbessert. In dieser Arbeit wird der Zusammenhang der gesamten Prozesskette, von der Synthese bis zur Charakterisierung der Schichten, mit besonderem Blick auf die partikulare Oberflachenchemie untersucht. Auf diese Weise kann dieser Einfluss aus einer Hand uberpruft und Randeffekte weitgehend vermieden werden. Today, polymer nanocomposites are of growing interest for the production of functional coatings. For this purpose, tailored and surface-modified nanoparticles are incorporated into a polymeric resin. Thereby, the characteristics of the used system can be altered and desired properties can be enhanced. In this work, the whole process chain, from synthesis to characterization of the coating, was examined with special attention to the surface chemistry of the nanoparticles. Hereby, the influence of the surface modification of the particles can be investigated while avoiding side effects.

Die Feinstzerkleinerung organischer Materialien in Ruhrwerkskugelmuhlen gewinnt zunehmend an Bedeutung. Wesentliche Aspekte sind neben der Erreichung der gewunschten hohen Produktqualitat die Energieeffizienz und die Reduktion von Mahlkorperabrieb, welche durch die Betriebsparameter der Muhle wesentlich bestimmt werden. Die Untersuchungen geben Aufschluss daruber, wie die Parameter im Zusammenhang stehen und wie sich Regeln fur den Einsatz von Ruhrwerkskugelmuhlen zur Feinstzerkleinerung organischer Partikeln formulieren lassen. Neben den Betriebsparametern stellen vor allem die Produktformulierung sowie die Produktpartikelgrose wesentliche Schlussel zur Verringerung des Mahlkorperabriebs dar. Ultrafine milling of organic materials has become more and more important. Besides the desired high product quality major challenges are energy efficiency and the reduction of milling wear from grinding media. The study presents the correlation between operating parameters and shows how to achieve maximum product fineness under optimized stressing conditions. From these findings rules for the operation of stirred media mills for fine milling of organic materials can be derived. In addition to the operating parameters especially product formulation and particle size represent key parameters to reduce grinding media wear.

In the development of colloidal lipid drug delivery systems (DDS), the localization of the drug within the DDS, the protective potential of the DDS as well as the compatibility of the drug with the excipients are of special interest. In this study, Coumarin 6 (C6), a fluorescent dye frequently used to facilitate the traceability of DDS in vitro, is demonstrated as a tool to gain insight into the aforementioned properties by fluorescence spectroscopy. Both ways of loading C6 to solid colloidal DDS (pre-loading to the lipid matrix or post-loading to the ready DDS after its processing) led to a localization of C6 in the interfacial layer between solid lipid nanoparticles (SLN) and aqueous medium. In the case of pre-loading, C6 is homogenously distributed in emulsion droplets and expelled from the lipid matrix due to crystallization. Nanoemulsions distributed C6 in the liquid lipid matrix itself and cause a hypsochromic shift of fluorescence spectra. Larger surface areas of emulsion droplets due to smaller droplet sizes displayed more interaction of C6 with the aqueous phase as a bathochromic shoulder in fluorescence spectra. Measured fluorescence intensity was linearly dependent on light scattering of colloidal DDS of the same excipients. A simple method to evaluate the protective properties of DDS was presented and displayed that (i) nanoemulsions provide more protection compared with SLN and (ii) higher phospholipid concentration improve the protection within SLN. Practical applications: In the development of colloidal DDS, it is important to identify the localization and distribution of a (model) drug in compartments within the disperse system. The simple approach by fluorescence spectroscopy presented in this study supplies information about the localization of drug substances with properties comparable with the fluorescent probe used. The results assist formulation development as a quick screening tool to elucidate (i) the localization of the probe, (ii) the microenvironment of the probe (e.g., differentiation of the physical state of the disperse phase), and (iii) the protection of the probe against damaging agents from the aqueous phase. The fluorescent dye Coumarin 6 was applied as model drug in colloidal lipid drug delivery systems. Fluorescence spectroscopy proved able to identify the localization of the model compound, the physical state of the dispersed phase, and the protective potential of the DDS, especially dependent on phospholipid concentration.

Micromechanical aggregate properties are correlated with stress conditions during the dispersion process in a stirred-media mill. The fracture energy distribution of the aggregates measured via micro-compression tests is compared with the stress energy distribution in a stirred-media mill determined by CFD-discrete element method simulations and by an analytical model. The simulations are likened with a previously conducted one-way coupling. Furthermore, the rotor speed is varied to identify its influence on stress energy and number of contacts. Using the stress energy distribution and the measured fracture distribution, an effective dispersion fraction can be calculated and correlated with the dispersion progress.

Sodium polyacrylates permit a higher solids concentration during grinding, reducing the resulting particle size and/or specific energy consumption. Their impact on fine and ultrafine grinding of limestone was studied. Sodium polyacrylate with a low polydispersity index was found to be the most effective grinding aid for limestone and consequently applied for further nano-grinding experiments. Nano-grinding was most energy-efficient with the smallest grinding medium size. These ground nano-sized CaCO3 particles with sodium polyacrylate on the surface accelerated the hydration of ordinary Portland cement cement paste.

The influence of several process parameters like milling time, ball-to-beaker volume ratio, diameter of milling balls, and rotation frequency on the Knoevenagel condensation of vanillin and barbituric acid in planetary ball mills was investigated. These parameters determine the amount of energy provided for the reaction. Additionally, numerical simulations were carried out to describe the stress conditions in detail and to compute the drive power and energy transfer which cannot be measured directly. The mill and experimental parameters were modeled by the discrete element method with adequate coefficients of friction and restitution required to describe the powder behavior in the system. The coefficients were determined by correlation of experiments and simulations.

Wet grinding processes, especially in terms of nanoparticle production, are extremely energy intensive, and for hard and abrasive product materials, high grinding media wear is produced. In order to minimize energy consumption, the choice of the process parameters is crucial. The decision on the process parameters often depends on experience or a certain number of laboratory- or pilot-scale experiments. Here, an enhanced stress energy model is used, which enables the prediction of optimum process parameters for inorganic materials in wet stirred media milling based on results for a different grinding material. The use of this model to select the process parameters is also valid with regard to grinding media wear: The grinding media wear reaches minimum values if the optimum parameters pertaining to the minimum specific energy are chosen based on this enhanced stress energy model, especially if soft products are ground.