Cylindrical cells live or die by the quality of the jelly roll, and every machine in this collection is chosen for the tolerances that wind, slit, and cut decide. This section gathers the equipment used to take coated electrode rolls and bare current-collector foils through the upstream operations that determine internal alignment, edge quality, and tab geometry in 18650, 21700, 4680, and custom cylindrical formats.
Cylindrical assembly is unforgiving in two places: the slit edge of the electrode and the registration of cathode, separator, and anode as they enter the mandrel. Burrs and waves from poor slitting are a leading cause of internal shorts; uneven tension or off-center feed during winding produces non-uniform current distribution and accelerated capacity fade. The tools here address both, and they scale from R&D coupons up to pilot-line throughput.
Slitting and sheeting
Roll-to-roll slitters divide a wide mother roll of coated electrode or raw Cu/Al foil into narrower strips sized to the target cell diameter. Shear-cut (overlapping circular knife) configurations dominate for metallic foils and standard electrodes because they minimize burr formation; single-strip and 1-to-4 multi-strip layouts cover both prototyping and pilot output. Roll-to-sheet cutters serve the parallel workflow where individual sheets are needed downstream — for stack-style test cells, single-layer characterization, or feed into prismatic and pouch lines that share the same electrode stock.
Winding
Semi-automatic winders are the workhorse for R&D and small pilot runs: the operator loads cathode, anode, and two separator webs onto unwinding shafts, the leading edges are fed onto the mandrel, and tension control plus web guiding produce a concentric jelly roll. Automatic all-tab winders target the next-generation high-power formats — most visibly 4680 — where the foil itself is the tab. All-tab geometry shifts the tolerance budget: lateral edge alignment must hold within tight bounds on both top and bottom overhangs, because any drift translates directly into welding and current-collection defects.
If you are scoping a new cylindrical line, start with the slitter sized to your foil width and electrode hardness, then choose between semi-automatic and all-tab winding based on cell format. For complementary upstream and downstream stations see Battery Equipment, and for pouch and prismatic counterparts see Pouch Cells.
