What are the structural characteristics of the soft pack lithium battery and the square lithium battery pack?

The key material positive electrode material, negative electrode material and separator used in the soft pack lithium battery pack is not much different from the traditional steel shell and aluminum shell lithium battery. The biggest difference lies in the soft packaging material (aluminum-plastic composite film), which is The most critical and technically difficult material in soft-pack lithium batteries. Flexible 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 aluminum foil) and inner layer (multifunctional high barrier layer). Advantages of soft-packed lithium batteries: good safety performance, soft-packed batteries, unlike steel shell aluminum shell batteries that will explode. Lightweight, the weight of the soft pack lithium battery pack is 40% lighter than the steel shell lithium battery of the same capacity, and 20% lighter than the aluminum shell battery. The capacity of the soft pack battery is 10-15% higher than that of the steel shell battery of the same size and 5-10% higher than that of the aluminum shell battery. The internal resistance is small, and the internal resistance of the soft pack lithium battery pack is smaller than that of the lithium battery. At present, the minimum internal resistance of the domestic soft pack battery core can be less than 35m, which greatly reduces the self-consumption of the battery. The shape of the soft pack battery can be customized according to the needs of customers, and new battery cell models can be developed. With its excellent comprehensive performance, soft-pack polymer lithium battery packs are widely used in consumer electronics products such as smartphones, tablet computers, and wearable devices, and their rising speed far exceeds the average level of the lithium battery industry. Square lithium battery: The housing of the square hard-shell lithium battery is mostly made of aluminum alloy, stainless steel and other materials. The internal use of winding or laminated technology, the protection of the battery cell is better than that of aluminum-plastic film batteries (ie soft-pack batteries) , The safety of the battery cell has also been greatly improved compared to the cylindrical battery. The prismatic lithium iron phosphate battery pack usually refers to the aluminum shell or steel shell prismatic battery. The popularity of prismatic batteries is very high in China. With the rise of automobile power lithium-ion batteries in recent years, the contradiction between automobile mileage and battery capacity has become increasingly prominent , Domestic power lithium-ion battery manufacturers mostly use aluminum shell prismatic batteries with higher battery energy density. Structural characteristics of square lithium battery pack: square lithium battery, important structural components include: top cover, shell, positive plate, negative plate, diaphragm composed of laminated or winding, insulators, safety components, etc. The square type is mainly made of aluminum shell, and the structure is relatively simple. Unlike cylindrical batteries, which use higher stainless steel as the shell and have accessories such as explosion-proof safety valves, the overall accessories are lighter in weight, higher in reliability and higher in relative energy density. high. The prismatic lithium battery pack can be customized and processed according to the size of the product, so there are thousands of models on the market, and because there are too many models, it is difficult to unify the process; the processing automation level is not high, and the monomer difference is large , In large-scale applications, there is a problem that the life of the system is much lower than the life of the monomer. Advantages of prismatic lithium battery packs: high reliability of prismatic lithium battery packaging; high system energy efficiency; relatively light weight and high energy density; relatively simple structure and relatively convenient expansion. It is currently an important option to increase energy density by increasing monomer capacity ; The unit capacity is large, the system structure is relatively simple, which makes it possible to monitor the units one by one; another advantage brought by the simple system is the relatively good stability. Statement: Some pictures and content of articles published on this site are from the Internet, If there is any infringement, please contact to delete the previous article: Introduction to the performance and requirements of lithium battery separator materials