High Speed Shredder in Retired Lithium-Ion Battery Recycling

Time:2025-11-03

With the explosive growth of the new energy vehicle and energy storage industries, the demand for recycling retired lithium-ion batteries (in cylindrical, pouch, prismatic, and other forms) has entered a critical phase. However, the dual-shaft slow shredding technology that once dominated “electrode sheet line recycling” has exposed shortcomings such as high thermal runaway risks, low efficiency, and poor economic viability, as it struggles to adapt to the characteristics of retired lithium-ion batteries—enclosed in shells, charged, and with compact structures. Against this backdrop, the high speed shredder (high speed shearing and crushing machine) has become a core equipment to address industry pain points through targeted technological innovations, driving retired lithium-ion battery recycling from “extensive” to “safe, efficient, and refined”.

Dual-Shaft Slow Shredder VS High Speed Shredder

Dual-Shaft Slow Shredder

The greatest risk in retired lithium-ion battery recycling lies in “thermal runaway under charged conditions”. The dual-shaft slow shredder (with a rotational speed of only 5-70 rpm) operates at a low speed, which leaves ample time for temperature rise after battery short-circuiting. Once the separator is damaged and a short circuit occurs, the SEI film decomposes, the electrolyte comes into contact with lithium metal, and the positive and negative electrodes interact to release oxygen—eventually leading to inevitable fires (for ternary batteries) or gas emission and smoking (for lithium iron phosphate batteries).

High Speed Shredder

The core breakthrough of the high speed shredder lies in its ultra-high-speed operation design (rotational speed far higher than that of dual-shaft machines): by significantly shortening the temperature rise window after battery short-circuiting, it fundamentally inhibits the initiation of the thermal runaway chain. This feature eliminates the need for pre-discharge treatment of retired lithium-ion batteries, directly meeting the industry’s mainstream demand for “charged crushing”. It not only avoids the time and cost consumption of the discharge process but also enables the safe crushing of various retired lithium-ion batteries, completely resolving the fatal safety hazard of dual-shaft technology.

Core Advantages of High Speed Shredders in Battery Recycling

For retired lithium-ion battery recycling, the value of high shear shredders lies in their ability to address the industry’s most pressing challenges—safety, efficiency, and resource recovery quality—through technological design that aligns with the unique properties of retired batteries. Unlike dual-shaft slow shredders, which are limited by their low-speed and rolling-based crushing mechanism, high shear shredders deliver multi-dimensional advantages that underpin the entire recycling chain: they eliminate fatal thermal runaway risks during charged crushing, optimize material processing to boost subsequent process efficiency, ensure the integrity of recyclable metals (copper and aluminum) to enhance recovery purity, and resolve detailed engineering pain points to meet refined recycling demands. These advantages collectively make high shear shredders an irreplaceable core equipment in modern retired lithium-ion battery recycling lines.

The Process of Battery Shredding and Separation

Retired lithium-ion battery recycling is not a single crushing step, but a continuous process that links “shredding” to “pyrolysis” (for removing electrolytes and binders) and “metal separation” (for recovering copper and aluminum). The role of high shear shredders is to lay a solid foundation for the entire process by optimizing the state of crushed materials—making the otherwise complex multi-step workflow more efficient and reliable.

Step 1: Targeted Shredding by High Shear Shredders

The first and most critical step is breaking down the retired battery’s structure. High shear shredders use optimized shear blades and adjustable force control to accurately break through the battery’s high-strength shell and disperse its internally wound or disc-shaped electrode materials. Unlike dual-shaft slow shredders, which often leave “unbroken shells” or “unexpanded internal materials”, high shear shredders ensure full tumbling and expansion of materials. This not only avoids the need for secondary crushing but also maximizes the exposed surface area of materials—preparing them for efficient pyrolysis.

Step 2: Pyrolysis

After shredding, materials enter the pyrolysis stage, where electrolytes and binders are removed by heating. The expansion of materials from high shear shredding directly translates to a more than 30% increase in pyrolysis efficiency: the fully exposed material surface ensures uniform heating, avoiding the “local overheating” or “incomplete pyrolysis” issues caused by wrapped materials from dual-shaft shredding. This not only shortens pyrolysis time but also reduces energy consumption, laying the groundwork for high-purity subsequent separation.

Step 3: Copper-Aluminum Separation

The final key step is separating copper and aluminum foils from the pyrolyzed “black powder” . The integrity of copper and aluminum foils is critical here—and high shear shredders excel at preserving this integrity. Unlike dual-shaft machines, which crush via low-speed rolling, high shear shredders use precise shear force to avoid foil damage. This makes physical separation more efficient, reducing the need for costly hydrometallurgical impurity removal. The result is higher copper and aluminum recovery rates, lower processing costs, and ultimately, better economic returns for recycling operations.

Conclusion

The application of high shear shredders marks a pivotal shift in retired lithium-ion battery recycling technology: from “adapting to waste electrode sheets” to “tailoring to retired batteries”. By integrating core advantages in safety, efficiency, and resource recovery, and by optimizing the entire shredding-separation process, high shear shredders have become the backbone of the industry’s transition to refinement. As the new energy sector pursues a “full-lifecycle green closed loop”, high shear shredders will continue to evolve—further enhancing recycling efficiency and sustainability, and providing a solid technological foundation for the industry’s long-term development.