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High-end Coperion extruders for battery separator films

Coperion has handled many projects for all major battery components.

Coperion has huge experience and has handled many projects, from R&D lab scale up to complete production lines, for all major battery components, i.e. compounding of cathode and anode materials, separators for lead-acid batteries and lately an increasing number of separators for Li-ion batteries.

The separator is a key component of every Li-ion battery, which is located between the anode and cathode and separates those two electrodes from each other to prevent internal short circuits, which at worst can lead to a fire or even an explosion. Hence, the separator plays an important role, when it comes to battery safety and reliability. Most battery separators are currently made out of polyolefins, where Coperion’s twin screw extruder systems have gained years of experience. Due to comprehensive engineering know-how, customized screw design and high process reliability Coperion systems ensure excellent quality of the final product.

For large-scale commercial production of microporous separators for Li-ion batteries there are two basic manufacturing processes. The so called wet process (with up to 70% oil) and dry process, both covered and distributed by Coperion. Especially the very demanding wet process requires precise machinery and feeding equipment to meet the narrow quality tolerances the market is looking for. Formulations with different levels of oil and polymers (PP/PE/UHMWPE) have been successfully tested in our lab to provide machines for various throughput rates and have been supplied to customers.   

Coperion also plays a major part in turnkey stretching lines and works together with renowned companies for the production of battery separator films. We provide first-class feeding equipment and high-end twin screw extruders as excellent core components for these systems. Coperion inside – for highly sophisticated separators. With Coperion extruders and feeding equipment, film lines are able to combine highest output rates with high quality levels and best in class reliability. Coperion’s constant endeavor to increase the throughput of separator film lines makes Li-ion batteries more economic.

Typical areas of application are primary and secondary batteries for:

  • Automotive (electric vehicles) 
  • Consumer electronics: Laptop computers / mobile phones / tablet PCs / cameras
  • Large scale stationary power devices
  • High power applications, tools, etc.