At present, there are mainly three mainstream Lithium-ion battery types, namely Cylindrical, Prismatic and Pouch. Different battery types mean different characteristics, and they have their own advantages and disadvantages.
Pouch Lithium-ion Battery
The key materials used in Pouch Lithium-ion Battery – positive electrode material, negative electrode material and separator – are not much different from traditional steel shell and Aluminum shell Lithium-ion batteries. The biggest difference is the packaging material (Aluminum-plastic composite film). It is the most critical and technically difficult material in the Pouch Lithium-ion Battery. The packaging materials are usually divided into three layers, namely outer barrier layer (usually an outer protective layer composed of nylon BOPA or PET), barrier layer (middle layer of Aluminum foil) and inner layer (multifunctional high barrier layer).
The packaging materials and structure of the Pouch Lithium-ion Battery give it a series of advantages. For example, the safety performance is good. The Pouch Lithium-ion Battery is packaged with Aluminum-plastic film in the structure. When a safety problem occurs, the Pouch Lithium-ion Battery will generally not explode like a steel shell or Aluminum shell battery. Light weight: the weight of the Pouch Lithium-ion Battery is 40% lighter than the steel shell Lithium-ion battery of the same capacity, and 20% lighter than the Aluminum shell Lithium-ion battery. The internal resistance of the Pouch Lithium-ion Battery is smaller than other Lithium-ion batteries. It can greatly reduce the battery's self-consumption. The cycle life of the Pouch Lithium-ion Battery is longer. The attenuation is 4% to 7% less than Aluminum shell battery for 100 cycles. The disadvantages of Pouch Lithium-ion Battery are poor consistency, high cost, and easy leakage. However, high cost can be solved by large-scale production, and liquid leakage can be solved by improving the quality of Aluminum plastic film.