Winder: Precision craftsman for battery molding

The winding machine is the core equipment that makes the positive and negative electrode sheet and diaphragm wind into cell in a specific sequence during the manufacture of lithium battery. Its winding precision is very important, which directly affects the internal structure and performance consistency of the cell. With the development of technology, today's winding machines are moving in the direction of high speed, high precision and intelligence. The new winding machine adopts advanced tension control technology, which can accurately adjust the tension of the positive and negative electrode sheet and diaphragm during the winding process, ensure that the winding is tight and uniform, avoid wrinkles, dislocation and other problems, so as to effectively improve the energy density and safety of the cell.

Coater: key equipment for electrode coating

The coating machine is responsible for uniformly coating the positive and negative electrode materials on the collector fluid, and its coating quality has a decisive influence on the charge-discharge performance and life of the battery. In recent years, the coating technology has been continuously innovated, from the traditional scraper coating to the slit coating, transfer coating and other more advanced methods. Slit coating technology has become the mainstream because of its high precision, high speed and good coating uniformity. It can precisely control the thickness and width of the coating, and the coating thickness deviation can be controlled within a very small range, so that the consistency of the electrode coating is greatly improved. At the same time, the intelligent degree of the coating machine is also improving, through the automatic control system, can realize the real-time monitoring and adjustment of the coating process, effectively improve the production efficiency and product quality stability.

Key Manufacturing materials: Determinants of battery performance

Positive electrode material

The cathode material is the key material that determines the energy density and output voltage of the lithium battery. Common cathode materials are ternary materials (such as lithium nickel-cobalt manganate, lithium nickel-cobalt aluminate) and lithium iron phosphate. Ternary materials have a high energy density and can provide more powerful power output for batteries, which is suitable for fields such as electric vehicles with high mileage requirements. The lithium iron phosphate material, with its excellent safety, long cycle life and low cost advantages, occupies an important position in the field of energy storage and some cost-sensitive application scenarios. With the deepening of technology research and development, new cathode materials continue to emerge, such as the research and development of high-nickel ternary materials is committed to further improve the energy density, and the modification of lithium iron phosphate materials is focused on improving its low temperature performance and electrical conductivity, in order to expand its application range.

Anode material:

The negative electrode material mainly plays the role of storing lithium ions, and its performance affects the charge and discharge efficiency and cycle life of the battery. At present, graphite anode materials occupy a dominant position in the market because of their advantages such as low cost, high crystallinity, low lithium potential and stable platform. However, in order to meet the increasing demand for high energy density, silicon-based anode materials have become a research hotspot. The theoretical specific capacity of silicon is as high as 4200mAh/g, which is much higher than graphite, but silicon will have a large volume expansion during the charge and discharge process, resulting in the destruction of the material structure and affecting the battery life. To this end, researchers modified silicon-based materials through technical means such as nano and composite to improve its cycle stability, and some of the results have begun to be gradually applied to actual production, which is expected to significantly improve the overall performance of lithium batteries in the future.

Electrolyte:

Electrolyte acts as the medium of ion conduction in lithium battery, and its performance has an important influence on the charge and discharge speed, high and low temperature performance and cycle life of the battery. The electrolyte is generally composed of lithium salts, solvents and additives. New lithium salts have been developed to improve the conductivity and stability of the electrolyte, such as lithium difluorosulfonimide (LiFSI), which has higher conductivity, better thermal stability and hydrolysis resistance than the traditional lithium hexafluorophosphate (LiPF6), and can effectively improve the performance of the battery in high temperature environments. In terms of solvents, the optimization of the mixed solvent system is constantly carried out to balance the solubility, volatility and safety of the electrolyte. Additives play a key role in improving electrode interface performance and inhibiting side reactions, and the comprehensive performance of lithium batteries can be significantly improved by reasonable selection and proportion of additives.

The continuous innovation and development of lithium battery manufacturing equipment and materials provides a solid guarantee for the improvement of lithium battery performance and the reduction of cost. In the context of the global acceleration of the transition to new energy, continuing to promote the intelligent upgrading of manufacturing equipment and innovative research and development of materials will be the core of the lithium battery manufacturing industry to maintain a strong momentum of development and achieve sustainable development. This is not only related to the wide application of lithium batteries in electric vehicles, energy storage and other fields, but also has far-reaching significance for the optimization of the global energy structure and the realization of green development goals.