Battery production process

　　1. (positive, negative) dry mixing → wet mixing → rolling paste on the conductive substrate → three-step drying → winding → trimming (cut to a certain width) → rolling → winding (standby) dry mixing ball mill, the ball is Glass balls or zirconia ceramic balls;

　　Wet mixing. Planetary mixer, the blades are installed on 2-3 shafts, the mixing effect is better. The amount of solvent in the wet material should be appropriate to form proper flow deterioration to obtain a smooth coating. The paste is coated on both sides of aluminum foil or copper foil. The thickness of the coating depends on the type of battery. Then pass through three heating zones to dry sequentially. NMP (or water) is evaporated from the coating by the flow of hot air or dry nitrogen, and the solvent can be recycled and reused. The purpose of rolling is to increase the density of the coating so that the thickness of the electrode meets the size of the battery assembly. The pressure in the rolling stage should be moderate to avoid loose powder during the coiling process.

　　2. Battery assembly

　　The assembly process of the cylindrical battery: the bottom of the insulated coil enters the cylinder → winding cell cylinder → inserts the mandrel → welding-collector enters the cylinder → inserts the insulating ring → tube rolling line → vacuum drying → liquid injection → assembly cap (PTC components, etc.) and Weld front lead→seal→x-ray inspection→→→→cycle aging formation quantity.

　　Square battery assembly process: from the bottom of the insulation to the steel frame tube composed of the battery pieces, the cathode current collector block welding the steel box gasket, the electrode guide combination cover (PTC element, etc.) of the anode current collector, welding and combination cover rotation laser Welding position, vacuum dryer, sealing-x-ray inspection-quantity-cycle aging.

　　Assembly process description: Take cylindrical battery as an example (the basic process of square battery is the same). Before winding the core material into the cylinder, the aluminum tape (0.080.15mm thick, 3mm wide) and nickel tape (0.040.10mm thick, 3mm wide) are ultrasonically welded on the positive and negative conductive substrates at the designated positions as collectors. lead.

　　The battery separator is generally composed of PE/PP2 layer or PP/PE/PP3 layer. The separator is heat treated at 120°C to improve its wear resistance and safety.

　　The positive electrode, separator, and negative electrode are superimposed and then wound into the drum. As the paste electrode is used, the paste material must be well combined with the substrate to form a high-density electrode. In particular, it is necessary to prevent the powder from penetrating the membrane, causing a short circuit inside the battery.

　　Before the winding unit is inserted into the cylinder, an insulating bottom is placed at the bottom of the cylinder to prevent short circuit inside the battery, which is the same as a normal battery.

　　The electrolyte is generally LiPF6 and non-aqueous organic solvents. Before vacuum injection, the battery should be vacuum dried for 24 hours to remove the moisture and moisture in the battery components, so as to prevent LiPF6 from reacting with water to form HF and shorten the battery life.

　　The battery seal adopts sealant, insert gasket, coil and cross-section shrinking process, and the basic principle is the same as that of alkaline rechargeable batteries. After sealing, the battery uses a mixture of isopropanol and water to remove oil stains and spilled electrolyte before drying. Use an odor sensor or sniffer element to check for battery leaks.

　　After the entire battery is assembled, the battery should use X-rays to determine whether the internal structure of the battery is normal, and check whether the battery is core line, steel shell cracks, welding points, short circuits, etc., to eliminate the above-mentioned defective batteries and ensure battery quality.