Illustration: Modern cells are precision products made through tightly controlled coating, assembly, and formation steps.
Electrode production
Active materials, conductive additives, and binders are mixed into slurry, coated onto metal foils, dried, and compressed by calendaring.
Assembly
Electrodes and separator are wound or stacked, inserted into a casing or pouch, filled with electrolyte, and sealed.
Formation and grading
New cells are charged and discharged in controlled cycles to form protective interphase layers. Testing grades cells by capacity, resistance, leakage, and safety behavior.