Lithium batteries occupy a place in people's daily life, but where does it come from? What are the links in the lithium battery production process? Although the lithium battery production process depends on different lithium battery manufacturers, there are some differences, but the principle is the same, so the main Lithium battery production process is also basically the same, generally have: ingredients, coating, rolling, cutting, slitting, welding ear, winding, packaging, baking, liquid injection, chemical formation, molding, volume detection, etc. Process.
In the above-mentioned steps necessary for the production process of the lithium battery, attention should be paid to five aspects from the selection of the material to the measurement of the volume after the molding:
First, improve the physical and chemical structure of the positive and negative active materials, which is the basic link of the lithium battery production process:
1. Proper ion doping of the material, 2. Improve the particle size distribution of the active material, and avoid excessively wide particle size distribution of the active material. 3. Use materials with disordered layer structure or thin layer structure as much as possible. Improving the surface structure of the electrode material;
Second, the high bond strength of the electrode coating is beneficial to reduce the cycle capacity drop rate, which is the most technical process in the lithium battery production process, so pay attention to:
1. The binder and solvent for forming the adhesive material should be pure, and the coated pole piece should not be stored for too long. 2. The ratio of the adhesive used in the mixture of the positive and negative electrode coating film and the active material should be appropriate to ensure the coating film. Do not drop the powder afterwards;
Third, the optimization of electrolyte composition, lithium battery production process for the electrolyte requirements is to maintain capacity and extend battery life:
1. Improve the conductivity of the electrolyte and reduce the polarization by optimizing the lithium salt, solvent and additives. 2. Inhibiting the reaction between the positive electrode material and the electrolyte. 3. Controlling the appropriate specific surface area and coating the carbon negative electrode material. Surface treatment such as film formation and surface chemical reaction to improve the surface structure of the anode material;
Fourth，After the preparation of the battery material is completed, the lithium battery production process enters the assembly process. At this time, it is necessary to pay attention to:
1. The capacity of the negative electrode is slightly larger than the capacity of the positive electrode. 2. After winding the positive and negative electrodes and the separator, the gap size between the positive and negative electrode sheets and the separator is not more than 0.5 mm, and the upper and lower deviations are not more than 0.5 mm.
Fifth，When measuring the volume, it is advisable to charge at a low rate according to national standards, generally 0.2C.
In general, in the process manufacturing stage should pay attention to the following proportional relationship: pole surface and pole piece compaction density, anode excess ratio, formulation process, electrolyte and positive and negative with the appropriate amount.
There are differences in each step of the lithium battery production process. Under normal circumstances, the ingredients, baking, and formation time are long, and the time is as little as 10 hours. The more time is two days and two nights; the other processes are faster, with an average of 5 or 6 hour. The entire lithium battery production process takes about 15 days.