What is a flexible battery? What's the difference between a cylindrical battery and a square battery?

At present, according to the packaging mode and shape of batteries, they can be divided into square, cylindrical, soft bag and other forms. The basic structure of soft-pack lithium battery is similar to cylindrical and square, except that soft-pack lithium battery is a liquid lithium-ion battery, which is wrapped with a polymer shell and structurally encapsulated with aluminum-plastic film to protect the internal battery materials. The following three pictures are: square battery, cylindrical battery and soft bag battery.

Fang Dian?

Cylindrical electricity?

Soft package electricity?

Flexible battery has the advantages of high energy density, strong safety, flexible layout, light weight and long cycle life. However, the disadvantages are complicated manufacturing process and poor product consistency. It is usually necessary to combine the high battery thermal management system to maximize the overall comprehensive performance. At present, the representative models equipped with flexible batteries are: Nissan Leaf,? Audi e-tron and so on.

At present, "aluminum plastic film", as one of the key materials for packaging soft-pack power batteries, is the material with the highest technical barrier in soft-pack lithium batteries. At present, the localization rate is less than 10%, mainly relying on imports, and the cost is high.

Aluminum-plastic film

For flexible batteries, the cost of aluminum-plastic film accounts for 15% to 20% of the battery cost, second only to cathode materials and separators. At present, the main technology exporters of aluminum-plastic film are Japan, South Korea and China, while European and American countries rarely apply for technology patents.

Text/Sun Weibo

This article comes from car home, the author of the car manufacturer, and does not represent car home's position.