Two Critical Pre-Steps for Safe and Profitable Recycling: Non-Negotiable Discharging and Capacity Grading Before Spent Lithium-Ion Battery Shredding

Discharging and capacity grading are core pre-processing steps prior to the shredding and recycling of spent lithium-ion batteries. They directly determine the safety baseline and economic benefits of recycling operations, and are essential for standardized industry practices.

Discharging is an inviolable safety threshold. Even if spent battery cells appear visually defective, they still retain considerable residual charge. Shredding charged cells poses a high risk of internal short circuits caused by mechanical impact, which triggers thermal runaway. This can lead to fires, explosions, and the release of toxic and harmful gases, resulting in permanent equipment damage and severe casualties. Thorough discharging eliminates such safety hazards at the source.

Capacity grading is the key to maximizing resource value. By accurately testing core parameters such as remaining capacity and internal resistance of each cell, scientific value classification can be achieved: cells with over 80% remaining capacity are suitable for second-life applications, offering far higher value than direct shredding and recycling; low-capacity cells are more appropriate for shredding to extract valuable metals. Omitting this step not only causes severe waste of high-quality resources but also increases the difficulty and cost of subsequent sorting, significantly reducing overall recycling profits.

These two pre-processing procedures are fundamental industry operational standards and the core means for practitioners to balance safety, economic benefits, and compliance.