Non-Destructive Mechanical Characterization of 4680 Cylindrical Lithium-Ion Cells for Cell-to-X Integration

Electric vehicles offer a sustainable alternative to combustion engines but still face range and safety limitations. Integrating battery cells as structural elements (Cell-to-X, CTX) is a promising route to address both, but requires cells that reliably withstand everyday mechanical loads. This study presents a non-destructive mechanical characterization of commercial 4680-format cylindrical lithium-ion cells (Supplier 1), combining quasi-static compression tests (hemispherical and cylindrical indenters) across state of charge (SOC) and indentation depth, cyclic aging over up to 150 cycles, and post-mortem computed tomography (CT) analysis. Deformation remained predominantly reversible up to indentation depths of 0.5 mm for the hemispherical and 1.8 mm for the cylindrical indenter, and peak forces of up to 9.16 kN were sustained without functional or electrical failure, although localized plastic casing deformation was observed in individual cells at the highest tested depths. For the cylindrical indenter, peak force increased consistently with SOC and indentation depth, consistent with prior literature, while temperature and voltage remained stable throughout loading, with no immediate evidence of an internal short circuit. For the cells with a sufficiently complete cycling record, capacity loss over the valid cycles amounted to 1.8–2.9% per 100 cycles for the mechanically loaded cells, compared with 2.0% for an unstressed reference cell. Post-mortem CT imaging confirmed deformation remained confined to the outer casing and outermost jelly-roll layers without affecting internal structure or performance. These results provide preliminary evidence that the tested cells can tolerate structurally relevant mechanical loads without loss of function, supporting further development of CTX architectures.