리튬 이차전지용 복합기재 기술 특허 동향 분석 - 주요 출원인 중심으로

This study analyzed patents on composite current collectors for lithium secondary batteries to identify the technological trends. A country-specific patent analysis showed that Korea, Japan, and the United States had the largest number of patents, in that order, while a year-by-year analysis highlighted 2014. Regarding technology, polyolefin-based polymer film materials held the most patents, followed by winding for electrode assembly structures and welding-based methods for electrical tap connections. A qualitative analysis of four key companies examined their polymer film materials, electrode assembly structures, and improvements. These findings suggest that no optimal solution for polymer film materials, tap connections, or assembly structures has been established. Nevertheless, efforts were identified to enhance performance by utilizing the structural properties of polymer film layers. In addition, companies sought to address challenges such as the inapplicability of existing tap connection methods, electrical conductivity issues, lithium dendrite formation, active material layer detachment, leakage, and short circuits. The study findings highlight the need for further technological advances to optimize composite current collectors. These results are expected to contribute to ongoing research and the sustainable growth of the secondary battery industry.