In the previous article, we've talked about the equipment related to the Anode Material, and today we would like to introduce the equipment used in Cathode Material.
Cathode materials are one of the main parts of Lithium-ion batteries, thus constitute the power battery of new energy vehicles.
Cathodes are mainly divided into Lithium Iron Phosphate(LFP), Lithium Manganate(LMO) and Ternary Lithium Batteries. LFP is cathode material of lithium-ion batteries, with the advantages of long cycle life, good safety performance, low manufacturing costs, but low energy density. Ternary Lithium Batteries is cathode material in a certain proportion of Nickel-Cobalt-Aluminum(NCA ) or Nickel-Cobalt-Manganese (NCM), which has become the main choice for new energy vehicles and reached about 60% cars installation for the feature of high energy density. At the end of 2018 the energy density of Chinese Monolithic Cells has reached 265Wh/kg. What's more, CATL launched the 811 Ternary Lithium Batteries in 2019 that up to 304Wh/kg. The high energy density of Ternary Lithium Battery makes mainstream electric vehicles achieved mileage of 400 km or more, and some models even up to 500 km, which effectively reduced the anxiety about mileage of electric vehicles.
Cathode Material Industry Chain
The upstream of cathode material is made of mineral raw materials such as Lithium, Cobalt, and Nickel, and other mineral raw materials, which are combined with conductive agents and binders to make precursors. The precursor is synthesized by a certain process to prepare cathode material used in different fields. The following is a structural diagram of the cathode material industry chain.
General Preparation Methods
1)Solid Phase Synthesis
Generally after grounding and mixing lithium salt such as Lithium Carbonate and Cobalt Compound or Nickel Compound, and then move to next step for sintering reactions.
The process is simple and raw materials are easy to find, which was extensively developed in the early stage of making lithium batteries. It also has weak points such as limited capacity, poor mixing homogeneity and stability, terrible quality consistency between batches, etc.
Use organic complexes to prepare complex precursors containing Lithium-ions, Cobalt or Vanadium-ions, and then make sintering reactions. The advantages are better mixing effect, greater uniformity and stability, and higher capacity than solid phase method.
Using the method of preparing ultrafine particles developed in the 1970s to produce cathode materials. Except for the advantages of complex method, the capacitance of the prepared electrode materials is greatly improved, which is developing rapidly at home and abroad.
4)Ion Exchange Method
As the LiMnO2 prepared by the ion exchange method has a reversible discharge capacity of 270mA•h/g, so it has become a new research focus with the features of stable electrode performance and high capacity. However, it's too far to implement due to some steps consuming time and energy such as recrystallization and evaporation.
The following chart is a typical production process. S&L provide mixing equipment for the step before 1st sintering, difference batch mixers for finished product, even for plough paddle dryer during the process for High Nickel Cathode Material.
1) Plough mixer -LDH Series
Plough Mixer is the essential choice for mixing lithium battery material like Ternary Precursor.
Plough mixer is composed of cylindrical body, plough agitator, chopper assembly, drive system and discharge valve. With the help of high-speed choppers to break lumps, the material forms a centrifugal convection movement during high-speed mixing, which can get perfect mixing homogeneity in a very short time. It has advantages mentioned below.
-Short mixing time and high efficiency
-Convenient for cleaning and maintenance
-High-speed chopper especially designed for lithium battery
-Wear-resistant ceramic ploughs or Tungsten Carbide coating to avoid lithium battery material & metal ion
-Wear-resistant vessel, Ceramic lining inside mixer body to isolate lithium battery material from metal ions
-Special seals for main shaft and choppers designed for lithium battery industry
-Customized discharge valve optional for lithium battery Industry
2)Plough Paddle Dryer-LPH Series
Drying process is essential in processing high nickel products. By adding heating jacket, vacuum design and dust filter to the original plough mixer, it can make the wet material forming convection mixing along the cylinder wall, and finally get uniform heating in a certain time. The mixer body is made of wear-resistant Titanium material, which is also anti-corrosion for quality assurance. It can also be equipped with mature blowback filter.
3)Ribbon Mixer- WLDH series
Horizontal ribbon mixer is widely used to reduce the batch mixing differences of the final product.
Ribbon Mixer consists of special U-shape body, ribbon mixing element, driving system and discharge valve. The outer ribbon pushes materials from two ends to the center and inner ribbon moves material from middle to two ends. The convection movement will be created to get perfect mixing homogeneity of the material. The features below give you great support during support.
-Soft mixing to avoid damaging the physical properties of the material
-Multiple choices of mixer body structure (U-shaped, droplet, cylinder shape)
-Double ribbons with Tungsten Carbide coating to isolate lithium battery materials from metal ions
-Special main shaft seal designed to avoid material leakage
S&L Group has been cooperated with SHANSHAN Technology Since 2018 and constantly provided equipment for anode and cathode materials including GBF reactor, horizontal ribbon mixer WLDH and plough mixer LDH. After close cooperation with the customer, we have developed a complete set of mixing solution for cathodes lithium battery, such as Ceramic Lining of mixer body, Tungsten Carbide Coating of agitator, mechanical seal of the main shaft and professional design of drive system.
After years of experience providing high quality and efficient mixing equipment for Umicore, LG, SK, Ronbay, Shanshan, Changyuan LICO and other leaders in lithium battery industry, S&L has successfully overcome various difficulties and acquired the core technology and material characteristics of the production for lithium battery raw material.