초단펄스 레이저를 이용한 유연 배터리의 비손상 프리폼 커팅 기술

Abstract

With the progress of flexible devices, numerous researchers aim to manufacture the flexible battery with freefrom at various scales. Laser cutting is considered as one of the essential processes to achieve on-demand manufacturing but continuous wave or long-pulse laser beam may cause large heat affect zone (HAZ) in cutting edge and may even result in failure of battery function. Herein, it was demonstrated that the sophisticated cutting process using ultra-short pulse laser is applicable for tailoring of flexible battery with multilayered structure. Based on the comparison of cutting results using nanosecond laser and femtosecond laser, we confirmed that laser cutting by femtosecond laser induces much less thermal damage on thin foil electrodes, separator, and electrolyte. Furthermore, we investigated the interaction of femtosecond laser with the materials composed of a flexible battery and implemented a process for cutting each material without causing any critical damage. To prevent a short circuit between the anode and cathode, which usually occurs during laser cutting of the actual battery, the double-side cutting process was done by adjusting the focal points of the laser beam. We assume that the proposed approach can be applied in a roll-to-roll based cutting process for the mass-production of flexible devices.