The growing demand for lithium-ion batteries requires improved performance and productivity. The formation of electronic conduction paths by carbon nanotubes (CNTs) is an important factor influencing electrode performance. However, only a few methods have been reported to allow direct and quantitative evaluation of CNT dispersion. Conventional ion milling for cross-sectional preparation exposes only CNTs in the interstices of active materials, limiting accurate assessment. In this study, we applied a fracturing method to prepare electrode cross sections, thereby exposing more CNTs in the observation area and enabling clear visualization of CNT networks. Furthermore, low-accelerating-voltage SEM enhanced the contrast between binders and CNTs, facilitating their separation and enabling quantitative evaluation of CNT linear density when combined with machine-learning-based image analysis. This study demonstrates a direct and quantitative method for assessing CNT distribution in lithium-ion battery electrodes.

Domestically produced edible salt is stored in warehouses under moisture absorption and desorption conditions while being subjected to pressures corresponding to loads of up to 3.0 N⋅cm⁻². During this storage process, severe caking may occur, presenting a critical quality concern. It has generally been recognized that applied load can influence key caking factors, namely critical relative humidity and bulk density. Accordingly, the present study investigated the relationship between these caking factors and applied load-induced pressure using edible salt edible salt. Furthermore, the impact of these relationships on caking strength was examined. The results demonstrated that changes in critical relative humidity induced by load were negligible, whereas bulk density exhibited a pronounced responsiveness. Moreover, variations in bulk density under load led to significant changes in caking strength. These findings confirm that the effect of load-induced pressure on the caking strength of edible salt is predominantly governed by alterations in bulk density.