Silicon-Carbon Anode Materials Processing Technology

Among advanced anode materials applied to lithium-ion batteries, silicon–carbon anodes have been explored extensively due to their high capacity, good operation potential, environmental friendliness and high abundance. Silicon–carbon anodes have demonstrated great potential as an anode material for lithium-ion batteries because they have perfectly improved the problems that existed in silicon anodes, such as the particle pulverization, shedding and failures of electrochemical performance during lithiation and delithiation.

Li22Si5 is formed from silicon material at high temperature, corresponding specific capacity is 4200mAh/g, it’s 11.29 times that of graphite anode material. At present, TSLA 4680 battery, Amperex 265kWh/kg NCM ternary battery, Guoxuan High-tech 210Wh/kg LFP electric core and GAC Sponge silicon battery pack all use silicon carbon anode technology, and the driving mileage has been increased from 300km to 600km or even more than 1000km. There’s still a lot of development space with the progress of technology in the future.

China Minmetals
Institute of Chemistry Chinese Academy of Sciences
BTR Group

ALPA has provided solutions and equipment to more than 30 silicon carbon materials companies and achieved satisfactory results. 

ALPA has unique research results and practical experience in the field of grinding and classification of silicon carbon anode materials (monatomic silicon, silicon oxide). 

Production line is customized according to actual production situation. Compact design, small footprint, less peripheral equipment, high system stability, environmental protection. 

Grinding and classifying system adopts automatic PLC control, the technology is in line with the international advanced level. Clear process route, reliable system, high efficiency and energy saving, easy operation and maintenance of equipment, with high cost performance. 

The whole set of equipment is processed by precision CNC machine tools. Each production step has special production and assembly requirements. The machine is easy to disassemble. Combined with characteristics of materials to be ground, it can ensure the purity and output of final products.

Fluidized Bed Jet Mill Grinding Process

After the compressed air is filtered and dried, it is sprayed into the grinding chamber at high speed through the Laval nozzle. At the intersection of multiple high-pressure airflows, the materials are repeatedly collided, rubbed, and sheared to be crushed. The crushed materials rise with the suction of the fan. The airflow moves to the classification zone. Under the action of the strong centrifugal force generated by the high-speed rotating classification turbine, the coarse and fine materials are separated.The fine particles that meet the particle size requirements enter the cyclone separator and dust collector through the classification wheel for collection, and the coarse particles descend to the crushing zone and continue to be crushed.

– Achieve full ceramization, no magnetic substance.
– Overall sintering ceramic rotor up to the world’s advanced level, the line speed up to 65m/s.
– Control particle sizes precisely, available particle size D50:1~25μm.
– Zirconia ceramic nozzle.
– Australia imports LINATEX protection,seamless protection,wear- resistant.
– Recoil gas mantle sealing disc is sintered overall.
– German standards automatic controlling technology.
– Mettler Toledo weight sensor,precise control the feeding amount.
– Automatic regulator valve, pulverizer inlet pressure controlling constantly.
– Pressure difference sensors and automatic adjusting throttle, maintaining the stability of the system resistance.
– Siemens PLC automatic control, product quality consistent and stable.

Air Classifier Process

Under the action of the fan, the material moves to the classification area at a high speed from the lower inlet of the classifier with the updraft. Under the action of the strong centrifugal force generated by the high-speed rotating classification turbine, the material is separated, and the fine particles meeting the particle size requirements enter the cyclone separator or dust collector through the blade gap of the classification wheel for collection. The velocity of some fine particles entrained by coarse particles disappears after hitting the wall, and then decreases to the secondary air outlet along the wall of the cylinder. Through the strong washing effect of the secondary air, the coarse and fine particles are separated, the fine particles rise to the secondary classification in the classification area, and the coarse particles drop to the discharge port for discharge.

– Air sealing system brings classify accurateing.
– Accurate classifying thanks to high efficiency classifying rotor.
– Particle size adjustable between 2-74μm.
– Classifying flow distribution technology brings narrow particle size distribution.
– The whole system is running under negative pressure.
– Dust on filter bag is cleaned by automatic impulse.
– Filtration rate can reach 99.99%.
– Back up filter behind dust collector to prevent dust entering air compressor.
– Automatic PLC control system for the plant. Simple operation.