Addressing Mechanical and Electrochemical Aging of Cylindrical LFP Battery Cells by Laser Structuring of Electrodes

First results for the implementation of ultrafast laser structured thick-film lithium iron phosphate (LFP) electrodes in cylindrical battery cells are presented, with a special focus on laser structuring without thermal modification of the active material and the winding quality of thick-film electrodes. It was shown in half-cell measurements that minor thermal modifications did not result in a reduction in specific capacity of laser structured electrodes. Cells with structured electrodes had a higher rate capability at discharge C-rates greater than 1C compared to cells with unstructured electrodes. Furthermore, line structured electrodes with a structure pitch of 300 µm showed no visible damage of the electrode coating after winding at a radius of 3 mm, whereby the unstructured reference electrodes showed visible crack formation and delamination from the current collector after winding at a radius of 5 mm.