Abstract
Li-ion cells of the industrially-relevant 21700 format were built on pilot-scale with tabs made from (a) the electrodes’ current collecting foils (Al and Cu, “foil tabs”) in comparison with (b) conventional tabs (Al and Ni) welded to the electrodes’ current collecting foils (“welded tabs”). Both cell types use the same anode (graphite), cathode (NMC622), separator, electrolyte, as well as the same tab positions. This allows a direct comparison of welded tabs and foil tabs regarding formation, C-rate capability, cell electrical resistance, and long-term cycling stability tests. Our data reproducibly shows 14.4% longer cycling stability and 11.2% increased total charge throughput in the case of the cells with foil tabs until 80% SOH, which is likely due to less inhomogeneities in the case of the foil tab design.
Highlights
Li-Ion Cells by Foil Tab Design.Cylindrical Li-ion cells typically contain one coated anode and cathode for energy storage
The process chain described in this paper starts with the already coated electrodes
Even if the improved cycling stability of the cell with foil tabs in Figure 4b,c would originate from an effectively lower depth of discharge due to reaching the cut-off voltages earlier due to their higher resistance, the long-term performance in terms of total charge throughput is significantly increased by the foil tabs (Figure 4c)
Summary
Cylindrical Li-ion cells typically contain one coated anode and cathode for energy storage. The electrical current transfer from the electrodes is managed by connecting the current collecting foils by tabs to the positive and negative terminals of the cells [1]. These tabs are typically welded to the current collecting foils in areas which are not covered by anode and cathode material (Figure 1a). In large-scale battery cell production, these coating-free parts are often realized by an intermitted coating process. Tabs are likely to cause inhomogeneities in the jellyroll [2,3], since they are usually thicker than the electrode coatings (single-sided coating thickness for anodes < 100 μm [4])
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
