HI-TECH LINE for the manufacture of polymer separators
Extech Smp Cast
Thanks to our knowledge and research, we are pleased to present our HI-TECH LINE, designed to meet the needs of manufacturers of polymer separators for lithium-ion batteries. The configuration of the line is the result of the experience gained and accumulated by our technical staff over the years dedicated to the construction of extrusion systems with single orientation in line, in close collaboration with our customers. The choice of the arrangement of the coextrusion line with all its auxiliary components, allow us to obtain the following advantages compared to our competitors:
- Reliability of operation due to a study of positioning of the various organs with particular regard to the angle of the extrusion head with respect to the chill roll, to the type of air blade in depression and to that in pressure;
- Use of an automatic thickness adjustment system that acts directly on the extrusion die;
- Electrical / electronic equipment located in suitable areas not subject to vibrations, and with easy access for maintenance operations;
- Wide operational spaces free from access difficulties and therefore safer for the staff;
- Ease of intervention for filter changes;
- Feeding of raw materials to the hoppers with gravimetric dosing systems.
In addition to the above, the reliability of the line is guaranteed by the careful choice of components.
The separator is a thin porous polymer film that isolates the anode from the cathode but which allows the transport of ions through the liquid electrolyte. Films obtained with dry processes are more suitable for a higher power density, given their structure with open and fairly uniform pores, while those made with wet processes have a lower power density as their porous structure is more tortuous.
Indicative characteristics of the product:
- Dimensional stability to mechanical and thermal stresses.
- Porosity not less than 40%
- Uniform ovoid pore shape in the machine direction (MD)
It must avoid the Shutdown phenomenon due to overheating (short circuit between anode and cathode)
Thickness included: between 16 and 38 microns
Weight: between g / m² 8.60 and 20.50
Production speed: up to fino mt / min. 300
Production: up to Kg / h 300/420
Useful width: mm 1600 / 2200
There are various stages in the production process, the extrusion of the primary film in the flat Extrusion Die, the crystallization of the film and the various stages of stretching.
The porosity will depend on the state of the primary film and on the characteristics , that the film assumes at each step.
The dry production process does not require solvents, therefore it is less polluting than the wet process.
In the dry process, blends of polymers can be used , at least one has a crystalline structure.
Generally, mixtures of PP and PE are used in single layer, or in coextrusion with three layers PP / PE / PP
Typical application of the porous separator polymer film placed between the anode and cathode in the cells of lithium-ion batteries (+)