Who is suitable for electric vehicles with 18650 lithium-ion batteries and soft-pack batteries?

Both are world-renowned electric vehicle brands. What makes their choice of power batteries so different? In the field of automotive power battery applications, where are the advantages and disadvantages of 18650 lithium-ion batteries and soft-pack batteries? The difference in the shape of the electrolyte is the key. As the two mainstream power batteries currently on the market, the 18650 lithium ion battery and the lithium polymer soft pack battery are distinguished according to the packaging material of the shell. The 18650 battery is generally packaged in a steel case (18 means a diameter of 18mm, 65 means a length of 65mm, 0 means a cylindrical battery), and the structure of the internal electrode sheet and the diaphragm is a winding type. The outer packaging of the lithium polymer soft-pack battery is made of aluminum plastic film, and the internal electrode sheet and the separator are laminated (stacked one by one). Although the appearance and internal structure are different, the principles of the two batteries are basically the same. Both batteries have a positive electrode, a negative electrode and an electrolyte. The positive electrode material is generally lithium cobalt oxide, lithium nickel cobalt manganese oxide (ternary material), lithium iron phosphate or lithium manganate, etc. The negative electrode material is generally graphite, and the electrolyte is Lithium hexafluorophosphate solution. The main difference between the two lies in one of the internal materials of the battery-the shape of the electrolyte: the electrolyte inside the lithium polymer soft pack battery is polymer, which is generally gel or solid, while the electrolyte inside the 18650 battery is generally liquid. Each has its advantages and disadvantages. The application scope is different. 18650 lithium ion batteries and lithium polymer soft pack batteries have their own advantages and disadvantages. At present, the 18650 battery has a high degree of automation, and the consistency and safety of the battery have reached a high level. In addition, the battery itself is small in size and light in weight, so that it has magical advantages in the modularization and standardization of system development. Many people believe that the use of 18650 batteries as the source of power for new energy electric vehicles is the best choice at this stage. However, the 18650 battery also has an unavoidable shortcoming, that is, the monomer capacity is low (generally around 2~4Ah). This makes the 18650 battery require a very large number of batteries in application, and the battery management system to maintain battery cell consistency and battery heat dissipation is also more complicated. Compared with the 18650 battery, the lithium polymer soft pack battery has a higher monomer capacity, and has the advantages of being thinner, arbitrarily shaped, and arbitrarily shaped (it can produce ultra-thin batteries of 0.33mm, 0.50mm, etc.) , Its main disadvantage is poor consistency and poor mechanical strength. Based on the characteristics of lithium polymer soft pack batteries, lithium polymer soft pack batteries are increasingly being used in mobile phones, notebook computers, mobile power supplies and other fields. However, due to the poor conductivity of the colloidal (or solid) electrolyte and large internal resistance, lithium polymer soft-pack batteries are rarely used in electric vehicles. Soft pack batteries are not all lithium polymer batteries. Since lithium polymer soft pack batteries are rarely used in electric vehicles, what type of battery is the laminated soft pack battery of Nissan Leaf? In fact, although lithium polymer soft-pack batteries are generally referred to as soft-pack batteries, soft-pack batteries can also use liquid electrolyte, so soft-pack batteries are not all lithium polymer batteries. Nissan Leaf’s battery is a soft pack battery using liquid electrolyte. Whether it is a lithium polymer soft-pack battery or a soft-pack battery whose internal material is liquid electrolyte, the soft-pack battery is generally encapsulated with aluminum-plastic film. The aluminum-plastic film has a thin thickness and poor mechanical strength. In extreme cases such as a car collision, the aluminum-plastic film is prone to breakage and cause accidents. This is the main defect of the use of soft-pack batteries in new energy vehicles. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: Overview of Lithium Iron Phosphate Battery!