Invoering
Biomass hard carbon precursor is a primary carbon material. It is obtained from natural biomass (e.g., rice husk, wood, coconut shell). The process uses pyrolysis and carbonization under an inert atmosphere. The temperature range is medium (500–1200°C). It has the disordered carbon layers and nano-porous structure of hard carbon initially. But it usually contains impurities. Its surface chemical properties are unstable. The particle size distribution is uneven. So it cannot be used directly for lithium/sodium battery anodes. It needs fine subsequent processing.
In the industrialization of hard carbon anode materials, processing bulk or coarse-grained precursors into micron-sized powders is crucial. These powders need uniform particle size, extremely high purity and regular morphology. Qingdao Epic Powder Machinery Co, Ltd. is a professional manufacturer of powder processing equipment. It has a thorough grasp of the performance of various powder processing equipment. The air classifier mill it produces is highly suitable for processing biomass hard carbon precursors.
Why choose an air classifier mill for processing?
The air classifier mill integrates mechanical impact grinding and air classification. Its working principle aligns perfectly with the stringent processing requirements of hard carbon materials. It has four key advantages:
1. Extreme purity: effective prevention of metal contamination
Battery materials have strict limits on metal impurities (e.g., Fe, Ni, Cr). These impurities can severely damage battery cycle life and safety.
Advantage: The ACM grinds based on particle-to-particle or particle-to-liner collision. It does not need metal grinding media (e.g., steel balls in a ball mill). This fundamentally prevents metallic contamination from media wear.
2. Precise classification: achieving a narrow particle size distribution
Hard carbon anodes need a highly uniform and controllable particle size distribution (PSD). Excessive fines reduce first-cycle efficiency and increase side reactions. Too many coarse particles affect electrode coating uniformity and ion transport.
Advantage: The equipment has a built-in dynamic classifying wheel. By adjusting the speed, it can control product fineness (D50, D97) in real time and precisely. Oversized particles are separated and returned to the grinding zone. This ensures only qualified particles are discharged. It guarantees exceptional batch-to-batch consistency.
3. Low-temperature processing: preserving the delicate microstructure
The electrochemical performance of hard carbon is closely linked to its unique disordered nano-porous structure. Excessive heat during processing may alter or damage this critical structure.
Advantage: The air classifier mill generates a large volume of air during operation. This air quickly carries away heat from grinding. It keeps the system at a relatively low temperature. Thus, it effectively preserves the inherent porous structure of the hard carbon precursor.
4. Morphology modification: increasing tap density
The impact and friction of high-speed airflow can “trim” the sharp edges of hard carbon particles. This makes their morphology more regular.
Advantage: This morphology optimization helps increase the material’s tap density. During electrode fabrication, more active material can be filled per unit volume. This ultimately enhances the battery’s energy density.
Practical application guidelines of ACM
To fully leverage the equipment’s potential, consider these points when processing biomass hard carbon precursors:
Control feed moisture: Dry the precursor to a moisture content of ≤5-8%. This prevents material adhesion and equipment clogging. It ensures continuous operation.
Optimize classifying wheel speed: Determine the optimal speed based on the target particle size (e.g., D97=15μm, 20μm, 30μm). Tests can help find this speed. Higher speeds generally yield finer products.
Select wear-resistant solutions: For highly abrasive raw materials with high ash content (e.g., rice husk-based precursors), use wear-resistant materials. Tungsten carbide or ceramic are good choices. They can make liners and grinding components. This minimizes the risk of contamination from equipment wear.
Conclusie
Looking ahead, market demands for batteries are rising. They need higher energy density, longer cycle life and better safety. This increases the need for high-performance, low-cost hard carbon anodes. It also imposes higher requirements on anode material consistency, purity and processing efficiency.
The air classifier mill has many core capabilities. These include contamination prevention, precise classification, low-temperature processing and morphology modification. These make it an indispensable key equipment in the biomass hard carbon industry chain. It provides reliable technical support for improving the overall performance of the final anode product.
Qingdao Epic Powder Machinery Co., Ltd. has profound technical expertise. It is committed to providing comprehensive support to global customers. Services include equipment selection, process solution design, installation, commissioning and after-sales service. It helps customers maximize the value of their hard carbon projects. For more information about our Air Classifier Mills (Models: MJW-A, MJW-W, MJW-L, MJL-W, En ACM-lab), please contact Epic Powder team.
