Generally, the thickness of aluminum foil for batteries is required to be within ±4%, and aluminum foil rolling mills are mainly controlled by online thickness control systems. Although some downstream battery manufacturers would like to control the thickness of aluminum foil for batteries to within ±2%, most of the equipment on the market today is unable to achieve this level of control accuracy. Factors affecting thickness tolerances include alloy composition, hydraulics, roll roundness and bearing accuracy. These factors work together to limit the possibility of current technology to achieve more stringent thickness control.
Mechanical Properties
| Tensile strengthσb (MPa) | Elongationδ10 (%) | Cupping test value (mm) | Note |
| 90 – 110 | 13 – 18 | 6.2 – 7.3 | Erichsen Test |
Physical Properties
| Physical Properties | Metric | English | Comments |
| Density | 2.73 g/cc | 0.0986 lb/in³ | AA; Typical |
Surface quality. Battery foils have extremely high demands on the surface quality of the foil, which requires uniform color, no serious streaks and color differences, no bumps and bulges, no residual oil and foreign matter pressed in, and no defects such as scratches and nicks. To ensure that the product meets this stringent quality standard, the finished battery foil should be inspected for pinholes and surface defects.
