LiCoO2 Texturing by Laser Induced Forward Transfer for Printed Microbatteries

Laser induced forward transfer (LIFT) is used to print Li-ion battery electrodes. We show a preferred orientation of LiCoO2 particles in the (003) direction relative to non-laser transferred materials. While the laser energy does not alter the degree of orientation, the number of passes and transfer distance both have a significant influence on the observed texturing. We use a geometric argument based on the arrangement of plate-like particles on the substrate to explain the observations. When the plate-like particles encounter a perfectly flat substrate, they are able to align flat, causing (003) domains parallel to the substrate to be over 30 times more predominant than either (101) and (104) domains. From this maximum degree of orientation subsequent passes decrease the overall texturing of the samples as transferred particles encounter increasingly rough surfaces. At larger transfer distances, the areal density of particles reaching the substrate decreases, resulting in increased available substrate surface area and therefore more predominant particle orienting.