The diaphragm is made of plastic film, which can isolate the anode and cathode of the battery to prevent short circuit; When the battery is overheated, the current conduction in the battery can be blocked by the closed-cell function. 1. Insulation layer, which can effectively prevent internal short circuit caused by contact between positive and negative electrodes. 2. Semi-permeable layer, which mainly exists in liquid batteries such as lithium-ion batteries, can organize relatively large molecules to pass through and only allow small charged ions to pass through, thus improving the concentration difference near the positive and negative electrodes, facilitating ion diffusion, and thus improving the storage efficiency of the battery.1. The roll surface temperature can be adjusted to meet the production requirements within 300℃. 2, the temperature uniformity of the roll surface is good, the roll surface can be effectively worked, and the process temperature difference is ≤ 1.5℃, which can be+1℃. 3. The roller surface temperature can be controlled by regions and sections.