Production process and advantages of ternary lithium ion battery cathode material

Production technology of cathode materials for ternary lithium-ion batteries

The three important links in the production of ternary cathode materials for lithium-ion batteries are abrasive mixing, high-temperature sintering, crushing and decomposition. The control of each link and the performance of the equipment will have a direct or indirect impact on the final product. Among them, grading, screening, and packaging are the final links of ternary materials. Let’s take a look at these links.

The particle size distribution of ternary lithium-ion battery materials will affect the specific surface area, compaction density, processing performance of the pole piece and the electrical performance of the battery. However, the crushing equipment can only control the particle size of the material, not the particle size distribution of the material. In order to control the particle size distribution of the material, classification equipment is required. The classification of ternary materials is generally to add an airflow classification device after the airflow pulverizer to directly classify the crushed products. According to the particle size distribution requirements of ternary materials, different air classifiers and classification processes can be selected.

In order to prevent the material from containing foreign matter or coarse particles, it is necessary to screen the ternary materials of lithium-ion batteries. The Dmax of ternary materials is at least less than 50m, but sometimes Dmax exceeds the standard. The screening efficiency of the vibrating screen is relatively high, generally 80%-95%; the raw material size range after screening is large, from 250 mm or more to 0.1 mm or 0.01 mm; the output per unit area is large; the adjustment is convenient, and the screen hole is less clogged. This screen requires special transmission equipment and consumes power.

　　
As far as the overall work of the vibrating screen is concerned, the most important components are the screen, motor and bearing. In the use of ternary cathode materials for lithium-ion batteries, the choice of the screen is very important. Because the manufacturing process of the ternary material should prevent iron impurities or other metals from being brought in, the screen should be made of non-metallic materials and should be resistant to alkali corrosion.

The packaging of ternary lithium-ion battery materials is generally vacuum packaging or filled with inert gas after vacuum. There are many types of vacuum packaging machines, usually divided into mechanical extrusion type, intubation type, box conveyor belt type, turntable type and thermoforming type. The principle of mechanical squeeze vacuum packaging is: After the packaging bag is full, 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 is low, so it is used where the vacuum is not high.

　　
One of the important quality indicators of ternary lithium ion battery cathode materials is particle size and particle size distribution, which will affect the specific surface area, tap density, compaction density, processing performance and point chemical properties of the ternary material. Therefore, the size and distribution of ternary materials for lithium-ion batteries should be strictly controlled.

The advantages of ternary cathode materials for lithium-ion batteries

1. The ternary cathode materials used in lithium-ion batteries are cheap and low-cost

2. Cycle performance is better than ordinary lithium cobalt oxide

3. The gram capacity is slightly higher than that of lithium cobalt oxide

4. Capacity and safety are relatively balanced

5. Good overcharge resistance, easy to synthesize

6. When charging and discharging with high current, the polarization is small. The battery can be charged at 3C and discharged continuously at 5C.