In this study, promotion of liberation and recovering of cathode active materials by the grinding process were investigated for a scrap sample simulating cathode slurry in lithium ion battery manufacturing process. In the grinding process, we tried to minimize the percentage of cracked cathode active materials and to maximize the weight ratio under 32 μm. During the grinding by a jaw crusher with a gap size 0.5 mm, it was confirmed that the cathode materials were volumetrically ground without as cracking cathode active materials as possible. The sample was then ground by the attritor with different size of grinding media (φ3 and φ10), and we found that the ground material was superficially ground without as cracking cathode active materials as possible in the case of using single grinding media size (φ10). Our results show that the combination of volumetric grinding and surface grinding can effectively promote the liberation state of cathode active materials without cracking.

It has been previously reported that bacteria exhibiting a collective motion spin a gear-shaped particle that are much larger than themselves. Such a collective biological motion is expected to be useful for the development of novel energy conversion systems. In our laboratory, we observed that Pt catalytic particles, which have a simpler structure than living organisms, exhibit a unique collective motion (repeated cluster formation and collapse) in an aqueous ethanol solution. Herein, we demonstrate the extraction of mechanical work from this collective motion. We observed that the collective motion of the Pt particles causes translation for spherical particles and spinning motion for a gear-shaped particle. Furthermore, we estimated the energy conversion efficiency from chemical energy to mechanical work via collective motion of the Pt catalytic particles.

In this study, basic research was conducted to develop numerical models for filling behavior, compaction process, and tensile test of compacts. Numerical calculations of the filling behavior using distinct element method were performed. The calculated results got a good agreement with experimental one, enabling us to perform the numerical analysis of the filling process. The powder compaction process was also performed using multi particle finite element method (MP-FEM) with the information on the particle position and radius obtained from the DEM calculations. The compaction pressures of the same order as the experimental results were obtained, suggesting that the powder compaction process was successfully analyzed numerically. Furthermore, using the compact geometry obtained from the compaction calculations, tensile tests were numerically calculated using the MP-FEM when a load was applied in the radial direction of the compact. The crushing process of the powder layer was successfully represented. It was shown that the tensile strength can be calculated from the numerical analysis. The particle filling behavior using DEM and the compaction and crushing processes using MP-FEM were successfully calculated numerically in a series.

In this study, porous structured catalyst particles were synthesized using template particles of various size through a template-assisted spray process. In addition, the internal structure of the synthesized porous catalyst particles was analyzed by using TEM Tomography, and the interconnected pore structures were confirmed inside the particles. Thereafter, these macroporous particles were assessed for their carbon monoxide (CO) oxidation performance, revealing a substantial influence of the macropore size on the catalytic performance. Furthermore, the porous catalyst particles prepared using 61 nm or 381 nm template particles showed the highest CO oxidation performance.

The physical properties of pressed foundation (PF) are affected not only by the composition of the ingredients but also by the internal structure of the molded product. In this study, we tried to observe the internal structure of PF moldings in three dimensions and with high resolution and investigated internal structural factors that correlate with the physical properties of PF. As a result, the powders constituting the PF were detected with sub-micron resolution by synchrotron X-ray CT measurements. Furthermore, the orientation of the plate-like powder was found to correlate with the feel properties of PF.