Product Code: ICA11_107

Numerical Studies of Laser Cutting on an Active Electrode Material for Lithium-Ion Batteries
Authors:
Dongkyoung Lee, NSF Center for Lasers and Plasmas in Advanced Manufacturing, Department of Mechanical Engineering; Ann Arbor MI USA
Jyotirmoy Mazumder, NSF Center for Lasers and Plasmas in Advanced Manufacturing, Department of Mechanical Engineering, Department of Materials Science and Engineering, University of Michigan at Ann Arbor; Ann Arbor MI USA
Presented at ICALEO 2011

One of the challenges during the lithium-ion battery manufacturing process is the sizing of electrodes with good cut surface quality. If the sizing process provides poor cut surface quality, internal short circuits in the cells and significant heat generation, which significantly affect battery performance, occur. Currently, electrodes are sized using mechanical cutting by rotary knives and dies, which could result in delamination, burrs, and edge bending. The laser cutting of electrodes could improve the cut surface quality with high speed because of its high energy concentration, fast processing time, high precision, contact free process, and flexible range of laser power. However, without understanding the underlying physics, these advantages might not be fully utilized. Electrodes are composed of current collectors and active electrode materials, such as graphite-coated copper and lithium metal oxide-coated aluminium for anodes and cathodes respectively. To analyze the laser cutting of these electrodes, understanding the laser cutting for each material is an essential step. In this study, a 3D self-consistent laser cutting model is adopted and solved numerically for graphite laser cutting. This model includes multiple physical phenomena, such as multiple reflections, heat transfer, surface tension, recoil pressure, and phase changes. The effect of laser power and scanning speed on graphite during the laser cutting is analyzed. Furthermore, the influence of the sublimation property of graphite during the laser cutting is observed.