Electrode cutting and notching are key steps in lithium ion cell manufacturing because they define the electrode edge quality and can introduce defects that influence performance and reproducibility. This work compares mechanical notching (punched) and laser cutting for commercial olivine type cathodes LFP and LMFP, with a focus on how electrochemical performance changes from lab scale evaluation to larger cell formats. Both notching routes were assessed using electrochemical testing, including long term cycling and asymmetric rate tests, and complemented by post mortem characterization of the electrode edges before and after cycling.
For LFP, laser cut electrodes show consistently 4–5% lower discharge capacities than punched electrodes in coin cells. The deviation scales with the relative area affected by laser induced edge defects (about 5.3% for the coin cell geometry), indicating that edge related inactive zones can measurably reduce accessible capacity when the edge contribution is high. In pouch cells, this effect largely disappears due to the smaller relative edge area, leading to comparable capacities for both cutting methods. For LMFP, performance differences related to laser processing are not evident under moderate cycling in coin cells, and pouch cell testing repeatedly shows no compromise in electrochemical performance.
Post mortem analyses suggest that laser affected edge regions can transform during cycling, including redistribution or partial covering of initial surface features (“smoothing”), while punched electrodes remain largely unchanged. Overall, the results of this study highlight that the relevance of cutting induced edge defects is material and format dependent, and that selecting an appropriate notching method is essential for robust scale up in electrode manufacturing.