Feeding: raw materials such as PE or PP and additives are pretreated according to the formula and then transported to the extrusion system.
Casting: In the extrusion system, the pretreated raw materials are melted and plasticized, and then the melt is extruded from the die. The melt is cast to form a base film with a specific crystalline structure.
Heat treatment: The base film is heat treated to obtain a hard elastic film.
Stretching: Cold stretch and hot stretch the hard elastic film to form a nanoporous film.
What are the technical characteristics of square, cylindrical and soft-pack batteries?
Square lithium-ion battery usually refers to aluminum shell or steel shell square battery. The popularity of square battery is very high in China. With the rise of automobile power lithium battery in recent years, the contradiction between automobile mileage and battery capacity has become increasingly prominent. Lithium battery manufacturers mostly use aluminum shell prismatic batteries with higher battery energy density. Because the structure of prismatic batteries is relatively simple, unlike cylindrical batteries, which use high-strength stainless steel as the shell and accessories with explosion-proof safety valves, the overall The attachment weight should be lighter and the relative energy density should be higher. Square batteries have two different processes: winding and lamination.
Cylindrical batteries are mainly steel-shell cylindrical lithium iron phosphate batteries, which are characterized by high capacity, high output voltage, good charge and discharge cycle performance, stable output voltage, large current discharge, stable electrochemical performance, and use Safe, wide operating temperature range, and environmentally friendly. It is widely used in solar lamps, lawn lamps, backup energy, power tools, toy models.
The structure of a typical cylindrical battery includes: positive electrode cover, safety valve, PTC element, current cut-off mechanism, gasket, positive electrode, negative electrode, separator, and casing.
Soft pack battery
The soft pack battery is a liquid lithium ion battery with a polymer shell. The biggest difference from other batteries is the soft packaging material (aluminum-plastic composite film), which is also the most critical and technically difficult material in the soft pack lithium ion battery . The packaging material and structure of the soft pack battery give it many advantages.