Lithium-ion batteries (LIBs) provide the largest source of electrical energy storage today. This paper covers the use of comminution processes and, thus, crushers and mills for particle breakage and dispersing, as well as classifiers for particle separation within the process chain, from the raw material to the final lithium battery cell and its recycling at end of life. First of all, the raw materials for the active material production have to be produced either by processing primary raw materials, or by recycling the spent lithium batteries. The end-of-life battery cells have to be shredded, the materials separated and then milled in order to achieve the so-called black mass, which provides a secondary material source with very valuable components. Using these materials for the synthesis of the cathode active materials, milling has to be applied in different stages. The natural graphite, increasingly used as anode material, has to be designed in mills and classifiers for achieving targeted properties. Nanosized silicon is produced by nanomilling using stirred media mills as a primary option. Conductive additives for LIBs, like carbon black, have to be dispersed in a solvent with machines like planetary mixers, extruders or stirred media mills. In the future, mechanochemical synthesis of solid electrolytes will especially require additional application of comminution processes.
This review describes the importance of comminution and classification processes to produce battery materials and battery electrodes, and to recycle production scrap and end-of-life battery cells. It shows how comminution and classification processes are integrated into the production of various active materials, such as spheronisation of natural graphite, grinding of nano-sized silicon and dispersion of calcined lithium metal oxides, and into the processing of electrode slurries using planetary mixers, extruders or stirred media mills. The use of mills and classifiers in the recycling of battery materials and the mechanochemical synthesis of solid sulphide electrolytes is another important topic.
It is well known that the functionality of inorganic materials strongly depends on the chemical composition, morphology, particle size, crystal facet, etc., which are strongly influenced by the synthesis process. The precise control of the synthesis process is expected to lead to the discovery of new functionality and improvement of the functionality of materials. For example, in a high-temperature solid-phase reaction, it is difficult to control the morphology of nanocrystals. On the other hand, synthesizing functional materials using solution processes, such as hydrothermal and solvothermal reactions, makes it possible to control the morphology and particle size precisely. Usually, the solution process is strongly related to the dissolution reprecipitation mechanism. Therefore, the material composition can be strictly controlled and is suitable for forming fine particles with high crystallinity. In this review paper, the role of the solvent in the solution process, its effect on particle size and morphology of the transition metal oxide, and the related functional improvement will be focused. Furthermore, the direct formation of functional thin films by the solution process and the morphology control by non-oxide materials by the topotactic reaction will also be introduced.
Solution processing is one of the important methods in the synthesis of functional materials. This method can create various compositions and control their crystal structure, particle morphology, and size. It is expected to lead to the development of new functionality of materials. This paper introduces the relationship between powder particle morphology and material functionality, explains the various environmental response functionalities of transition metal oxides synthesized by the environmentally friendly liquid-based method, and indicates that the morphology control associates material science with art. It arouses the reader's interest and implies further potential in developing future functional materials.
It is well established that the critical performance metrics for aerosol products are aerodynamic particle size distribution (APSD) and delivered dose uniformity (DDU). In broad terms, these performance characteristics dictate the efficiency and reproducibility with which an aerosol is administered clinically. However, these properties alone do not support in-vitro, in-vivo correlations. There have been numerous publications attempting to more directly link product performance testing to physiological relevance or further to draw direct correlations of relevance to bioequivalence testing for the development of generic products. While these novel methods have been employed in product development activity, their suitability for compendial testing has yet to be established. This paper explores the potential to establish biologically relevant compendial standards for dry powder inhaler products while maintaining accuracy and reproducibility of data collected to support the quality and performance of the product.
Dry powder inhaler formulations have garnered interest as a way to deliver drugs directly to the lungs in a stable, solid dosage form. Developing generics of brand-name dry powder inhalers is essential to their widespread availability but requires careful consideration in characterizing bioequivalence. This review highlights the standard characterization methods frequently employed as well as physiologically relevant measures that may aid in bioequivalence decisions. The necessity of considering in vivo relevance while performing in vitro testing is highlighted, assisting the field in shifting to physiologically relevant characterization methods.
Higher performance is constantly required in rare earth permanent magnets, which are an indispensable component of the motors of electric vehicles. When producing sintered magnets, advanced structural control is necessary in the powder metallurgy process in order to achieve high performance. Especially in recent years, it has become important to develop processes for Sm-Fe-N magnets and metastable phase magnets as next-generation magnets to replace the Nd-Fe-B magnets. Because the crystal grain refinement of sintered magnets is most effective for improving coercivity, production methods for raw powders have evolved from the traditional pulverization to chemical synthesis approaches, and as a result, a submicron-sized Sm-Fe-N powder with huge coercivity has been developed. State-of-the-art physical synthesis methods have also been applied successfully to the synthesis of nanopowders. Since control of the grain boundary is very effective in Nd-Fe-B magnets, this approach has also been evolved to Sm-Fe-N magnets by nano coating. On the other hand, since technologies for crystalline orientation control and high-density sintering are indispensable for improvement of remanence, new low-thermal load consolidation techniques such as spark plasma sintering are being developed for Sm-Fe-N magnets and metastable phase magnets in order to overcome the inherent low thermal stability of these materials.
Delve into the forefront of rare earth permanent magnet research with this insightful paper. With electric vehicles driving demand for higher-performance magnets, the quest for advanced structural control in powder metallurgy processes is paramount. Discover how innovative approaches in chemical synthesis have led to the development of submicron-sized Sm-Fe-N powders with remarkable coercivity. Explore the evolution of grain boundary control techniques and the emergence of low-thermal load consolidation methods like spark plasma sintering, crucial for enhancing remanence in next-generation magnets.
Spray drying is gaining traction in the pharmaceutical industry as one of the processing methods of choice for the manufacture of solid dosage forms intended for pulmonary, oral, and parenteral delivery. This process is particularly advantageous because of its ability to produce engineered particles with improved efficacy and stability by combining active pharmaceutical ingredients or biologics with appropriate excipients. Moreover, due to its high throughput, continuous operation, and ability to produce thermostable solid powders, spray drying can be a manufacturing method of choice in the production of drugs and other formulations, including vaccines, for global distribution. Formulation design based on a mechanistic understanding of the different phenomena that occur during the spray drying of powders is complicated and can therefore make the use of available particle formation models difficult for the practitioner. This review aims to provide step-by-step guidance accompanied by critical background information for the successful formulation design of spray-dried microparticles. These include discussion of the tools needed to estimate the surface concentration of each solute during droplet drying, their times and modes of solidification, and the amount of glass stabilizers and shell formers required to produce stable and dispersible powders.
Spray drying emerges as a pivotal method in pharmaceutical manufacturing, offering versatility across various delivery routes. Its capacity to engineer particles enhances drug efficacy and stability, vital for global distribution, notably for vaccines. Despite complexities in formulation design, this review elucidates practical steps and essential background knowledge crucial for successful spray-dried microparticle formulation. It navigates through estimating solute concentration during drying, solidification kinetics, and the role of stabilizers, providing invaluable insights for practitioners striving to optimize particle properties for therapeutic delivery.
A Review of the Fire and Explosion Hazards of Particulates
Released on J-STAGE: February 27, 2014 | Volume 31 Pages 53-81
Saul M. Lemkowitz, Hans J. Pasman