Effects of Tab Design in 21700 Li?Ion Cells: Improvements of Cell Impedance, Rate Capability, and Cycling Aging

Li-ion cells of the industrially relevant 21700 format are investigated experimentally by systematic variation their tab design. To observe effects design only, built on pilot scale using same electrodes, electrolyte, and separator. Tabs varied regarding 1) conventionally welded tabs 2) made from electrodes’ foils (“foil tabs”), as well number. Conclusions drawn cell impedances, rate capability (0.5C–3C), heating behavior, cycling aging. Cells with a multitab show reduced impedance (1 kHz) 62%, an improved charging ?17% for 3C, cycle stability 26.5%, charge throughput 22.8%. For check-ups at C/10, improvements in life 51.1% 42.4% observed, respectively. The is due to reduction inhomogeneities jellyrolls observed X-ray computed tomography. data put into context other studies conclude order magnitude variation. Based experimental findings, estimations 46800 energy content impedance.