Influence of Laser-Generated Cutting Edges on the Electrical Performance of Large Lithium-Ion Pouch Cells

Abstract

Laser cutting is a promising technology for the singulation of conventional and advanced electrodes for lithium-ion batteries. Even though the continuous development of laser sources, beam guiding, and handling systems enable industrial relevant high cycle times, there are still uncertainties regarding the influence of, for this process, typical cutting edge characteristics on the electrochemical performance. To investigate this issue, conventional anodes and cathodes were cut by a pulsed fiber laser with a central emission wavelength of 1059–1065 nm and a pulse duration of 240 ns. Based on investigations considering the pulse repetition frequency, cutting speed, and line energy, a cell setup of anodes and cathodes with different cutting edge characteristics were selected. The experiments on 9 Ah pouch cells demonstrated that the cutting edge of the cathode had a greater impact on the electrochemical performance than the cutting edge of the anode. Furthermore, the results pointed out that on the cathode side, the contamination through metal spatters, generated by the laser current collector interaction, had the largest impact on the electrochemical performance.

The Role of Pilot Lines in Bridging the Gap Between Fundamental Research and Industrial Production for Lithium‐Ion Battery Cells Relevant to Sustainable Electromobility: A Review

“…Process speeds are higher compared with conventional cutting, tool wear plays a minor role, as laser cutting is a contactless process, and cutting geometries can be flexibly adapted to new electrode shapes. [ 5,138–141 ] In large‐scale production, laser‐based technologies are predominantly applied for upstream electrode notching and separation for ESC assembly that uses single sheets.…”

“…In addition, melt formation, ablation, and melt superelevation are observed by laser treatment ( Figure 11 a). [ 139,140 ]…”

“…Separation by laser treatment is associated with damages to the binder matrix (risk of undefined loss of active material), melt formation, ablation, and melt superelevation, which can adversely affect the electrochemical performance or even pose safety issues. [ 139,140 ] Laser‐cutting parameters have to be adjusted toward a reasonable compromise between achievable cutting speed, reduction of thermal damage to the electrodes, and investment costs. [ 138,140 ] Loose particles that arise during cutting must be fully removed, especially particles that exceed the size equivalent of the separator thickness can pierce the separator and pose a safety issue.…”

Effect of Fluence and Multi-Pass on Groove Morphology and Process Efficiency of Laser Structuring for 3D Electrodes of Lithium-Ion Batteries

“…Recently, laser processing has been partially applied in battery manufacturing, such as electrode cutting and battery tab and case welding, because it is possible to obtain a precise and fast process with high energy density [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ]. In addition, laser processing has been reported as a technology that can effectively manufacture 3D electrodes.…”

Lithium-Ion Batteries: Latest Advances and Prospects

“…In response to this call, twelve research papers [19][20][21][22][23][24][25][26][27][28][29][30] and one case report [31] were thoroughly peer-reviewed and published. The published research papers covered advances in several fronts of the technology, including detailed fundamental studies of the electrochemical cell and investigations to better improve parameters related to battery packs.…”