The manufacturing process of lithium-ion batteries varies slightly depending on the manufacturer, but since the principle is the same, the important manufacturing processes are basically the same, which generally include: material preparation, coating, rolling, cutting, slitting, welding of tabs, winding, packaging, baking, electrolyte injection, formation, molding, and capacity testing.
In the essential steps of the lithium-ion battery manufacturing process described above, there are five key issues to consider from material selection to post-molding capacity testing:
I. Improving the physicochemical structure of the positive and negative electrode active materials is a fundamental step in the lithium-ion battery manufacturing process. This involves appropriate ion doping of the materials, using materials with disordered layered structures or thinner layers whenever possible.
Second, the high adhesion strength of the electrode coating helps reduce the cycle capacity degradation rate, which is the most technically demanding process in lithium-ion battery production. The ratio of adhesive to active material used in the mixing of positive and negative electrode coatings must be appropriate to ensure that no powder falls off or detaches after coating.
III. Optimization of Electrolyte Composition: The requirements for electrolytes in lithium-ion battery manufacturing processes are to maintain capacity and extend battery life. This is achieved by optimizing lithium salts, solvents, and additives to improve electrolyte conductivity and reduce polarization.
IV. After the battery materials are prepared, the lithium-ion battery production process enters the assembly stage. At this time, it is important to note that after the positive and negative electrodes and the separator are wound, the particle size of the gap between the positive and negative electrode sheets and the separator should not be greater than 0.5 mm, and the vertical deviation should not exceed 0.5 mm.
5. When performing capacity testing, it is advisable to use low-rate charging, generally 0.2C, in accordance with national standards.
