Production process of cathode material for ternary lithium ion battery
●Grading
The particle size distribution of ternary lithium-ion battery materials will affect the specific surface area, compaction density, pole piece processing performance and electrical performance of the battery. The pulverizing equipment can only control the particle size of the material, but cannot control the particle size distribution of the material. For the classification of ternary materials, an air classification device is generally added after the air pulverizer, and the pulverized products are directly classified. According to the particle size distribution requirements of ternary materials, different air classifiers and classification processes can be selected.
●Sifting
In order to prevent the material from containing foreign matter or coarse particles, it is also necessary to sieve the ternary material of the lithium-ion battery. The Dmax of the ternary material is at least less than 50μm, but sometimes the Dmax exceeds the standard. The screening efficiency of vibrating screen is high, generally 80%~95%; the range of sieving raw material particle size is large, from more than 250mm to 0.1mm or 0.01mm; the output per unit area is large; it is easy to adjust, and the screen holes are less blocked. This kind of sieve requires special transmission equipment and consumes power.
Regarding the whole work of the vibrating screen, the most important parts are the screen, the motor and the bearing. In the use of ternary cathode materials for lithium-ion batteries, the selection of screen mesh is critical. Because the process of ternary material should prevent the introduction of iron impurities or other metals, the material of the screen should be non-metallic and resistant to alkali corrosion.
●Packaging
Ternary lithium-ion battery materials are generally packaged in vacuum or filled with inert gas after vacuum. There are many varieties of vacuum packaging machines, which are usually divided into mechanical extrusion type, intubation type, chamber conveyor belt type, rotary table type and thermoforming type. The principle of mechanical extrusion vacuum packaging is: after the packaging bag is filled, use elastic items such as sponges on both sides to remove the air in the bag, and then seal it. This method is the simplest, but the vacuum degree is low, and it is used in occasions where the vacuum degree is not required.
One of the important quality indicators of cathode materials for ternary lithium ion batteries is particle size and particle size distribution. Particle size and particle size distribution will affect the specific surface area, tap density, compaction density, processability and spot chemical properties of the ternary material. Therefore, ternary materials for lithium-ion batteries need to strictly control the particle size and particle size distribution.
Advantages of ternary cathode materials for lithium ion batteries
1. The ternary cathode material of lithium ion battery is not expensive and the cost is low
2. The cycle performance is better than normal lithium cobalt oxide
3. The gram capacity is slightly higher than that of lithium cobalt oxide
4. Balance between capacity and security
5. Good resistance to overcharge, easy to synthesize
6. When charging and discharging at high current, the polarization is small. The battery can be continuously charged at 3C and discharged at 5C with high input and output capability.
Under the general trend of the ternary lithium-ion battery industry, many domestic cathode material companies are facing huge foreign patent fees in the development. Domestic patent applications for ternary materials are relatively scattered, especially the leading companies are less involved, and the overall research atmosphere is not strong. Domestic companies should pay attention to the research and development of cathode materials and the protection of intellectual property rights; second, the safety and cost of ternary materials, etc. There is a large room for development.
与此原文有关的更多信息要查看其他翻译信息,您必须输入相应原文