Related concepts and production processes of lithium-ion batteries

　　Lithium batteries are a type of batteries that use lithium metal or lithium alloy as the negative electrode material and use a non-aqueous electrolyte solution. Now people are no strangers to lithium batteries, especially after they are widely used in vehicles, electric vehicles and other transportation fields, people's attention to lithium batteries has increased to a higher level. At the same time, lithium-ion battery manufacturers are constantly improving the production process of lithium-ion batteries.

　　Lithium battery concept 　　Lithium battery is a type of battery that uses lithium metal or lithium alloy as the negative electrode material and uses a non-aqueous electrolyte solution. Edison was the first scientist to invent lithium batteries. Of course, now people are no stranger to lithium batteries, especially after they are widely used in vehicles, electric vehicles and other transportation fields, people's attention to lithium batteries has increased to a higher level.

　　Lithium cobaltate batteries and ternary lithium batteries (ternary nickel-cobalt-manganese) 　　2, according to use; can also be divided into two categories: 　　The first one is digital batteries, which are our daily mobile phones, tablets, mobile power supplies, etc. , These are all digital batteries. The second type is power batteries, which are batteries used by Tesla, BYD, some new energy electric vehicles, and drones. These batteries require a large instantaneous current, and digital batteries cannot meet the instantaneous high current, so this The class is also called high-rate battery, which is more expensive than digital batteries.　　3. According to the shell materials, it can be divided into three categories: 　　The first category, steel shell batteries, as the name implies, the shell is made of steel.　　 The second category, aluminum shell batteries, similarly, the shell is made of aluminum.　　 The third category, polymer batteries, the shell is a polymer material, mostly silver, a few manufacturers make black, the industry has become black. 4. According to the shape, there are also three categories: 　　 the first type, cylindrical batteries, which are used a lot, such as 18650, 26650, etc., this general combination is used, and the combination with less can be used as digital products, like early notebook computers , Generally 8 18650, mobile power, one to five or six combinations, there are more than 7000 series and parallel combinations of Tesla's 18650. The second type is square batteries. Most of these batteries are polymer batteries, because this polymer is very malleable and can be made into many shapes. The length, width and height can be adjusted at will. Now most digital products use this type of battery. .　　 The third type, abnormal-shaped batteries, are some weird-shaped batteries. According to the needs of the product, the batteries must also have a matching shape. For example, the popular smart wearable products, such as smart bracelets are ring-shaped, so the battery is also made into a ring shape.

　　The structure of the lithium battery 　　The structure of the lithium battery is divided into five parts, namely the positive electrode, the negative electrode, the separator, the electrolyte and the casing.　　 (1) Lithium battery positive electrode contains active material, conductive agent, solvent, binder, matrix and other materials.　　 (2) The negative electrode of a lithium battery contains active materials, binders, solvents, substrates and other materials.　　 (3) Lithium battery separator 　　 (4) Lithium battery electrolyte 　　 (5) The lithium battery shell includes steel shell, aluminum shell, cover plate, tabs, insulating tape and other hardware.

　　Lithium battery production flow chart　　The production process of lithium batteries is not very consistent for each manufacturer, but most of them are inseparable from these links, as shown below:

　　The details are as follows: material preparation-homogenization-coating-rolling-slitting-baking-winding-into the shell-laser welding-baking-injection-pretreatment Filling-sealing-cleaning-aging-full inspection-storage-shipment.　　Lithium battery production process 　　 Objectively speaking, the lithium battery production process is divided into three sections, one is pole piece production, the other is battery cell production, and the third is battery assembly. In the lithium battery production process, the production of pole pieces is the foundation and the production of battery cells is the core. Battery assembly is related to the quality of the finished lithium battery. The specific steps of the lithium battery production process flow include positive electrode slurry drawing, negative electrode slurry drawing, positive electrode sheet, negative electrode sheet, steel shell assembly, liquid injection and testing, and packaging.

　　Introduction to the process flow of lithium battery production is well known, the process flow of lithium battery production is quite complicated. After all, the safety performance of lithium ion battery products is directly related to the life and health of consumers. Natural lithium battery production and manufacturing on the equipment performance, accuracy, stability and automation The level has higher requirements. Take the preparation of electrode slurry in the lithium battery production process as an example. This link is the foremost link in time and is also the most important link in the entire production process. After all, the electrode slurry mixing and dispersion process has an impact on product quality greater than 30 %. What's the reason?　　The reason is that the preparation of the positive and negative slurry of lithium batteries includes a series of processes such as the mutual mixing, dissolution, and dispersion of liquid and liquid, and liquid and solid materials, and is accompanied by changes in temperature, viscosity, and environment. In the positive and negative electrode slurry, the dispersion and uniformity of the granular active material directly affects the movement of lithium ions between the two electrodes of the battery, so the dispersion quality of the electrode slurry directly affects the product performance of the lithium battery. It can be seen that each production link of the lithium battery production process is closely related to product quality and safety. Every link in the lithium battery production process must be strictly and carefully managed, so as to improve the safety performance of lithium battery products. .