Mechanical Battery Recycling

During shredding, all battery materials—including active materials, current collectors, plastics, and binders—are mixed together. These must be separated in downstream processes. However, depending on the separation technologies used, some materials can be recovered more efficiently than others. Particular attention should be paid to copper and aluminum, which originate from the anode and cathode foils. If not properly separated, these metals can contaminate the black mass, reducing its purity and value.If batteries with different chemistries (e.g., NMC, LFP, NCA, LCO) are shredded together, the resulting black mass will be cross-contaminated, lowering its value and reducing the efficiency of downstream hydrometallurgical recovery processes.

Battery shredding introduces major safety hazards, including the risk of fire, harmful gas release, and airborne particulate matter. These risks are caused by residual electric charge, flammable electrolyte solvents, and reactive salts. Additionally, fine dust generated during shredding can pose health hazards to workers and environmental risks. Proper safety measures—such as fire suppression, gas filtering, dust collection systems, and PPE—are essential to mitigate these risks.

Shredding lithium-ion batteries places significant mechanical and chemical stress on key components—particularly the knives. Hard metals like stainless steel and chemically aggressive substances such as electrolyte salts contribute to rapid degradation. As a result, shredders require frequent maintenance, reducing overall operational uptime and increasing costs.

Vacuum drying is typically a batch process, whereas shredding is a continuous process. This creates a mismatch in throughput and may require buffering systems in between, introducing inefficiencies and additional complexity in the overall process flow.

The drying process needs to be designed to fit different electrolyte mixtures (expecting to process different batteries). In addition to that each electrolyte solvent mixture is kept confidential by the cell producer. Especially because of that processing parameter flexibility is required to ensure that all battery shreds are properly dried.

Effective electrolyte removal depends heavily on drying temperature. Higher temperatures improve solvent evaporation, while lower temperatures increase energy efficiency—so finding the right balance is critical. Typical electrolyte mixtures include solvents like dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), and ethylene carbonate (EC). Among these, ethylene carbonate has the highest boiling point. If drying temperatures are too low, EC may not fully evaporate, leaving behind residues that interfere with downstream processing.

During drying, battery solvents evaporate and are treated as off-gases in specialized systems. These vapors—including decomposition products from electrolyte salts like lithium hexafluorophosphate (LiPF₆) or fluorinated binders such as polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE)—are highly aggressive toward materials. Components such as vacuum pump seals and any materials in contact with the off-gases must be carefully selected to ensure durability and system reliability.

Decisions must be made about how pure each separated stream needs to be. For example, is it sufficient to recover a mixed metal fraction, or should ferrous metals, aluminum, and copper be separated individually? Higher purity increases the complexity, cost, and energy demand of processing. A cost-benefit analysis should guide these decisions to balance recovery quality with operational efficiency.

Each separated material stream results in some loss of valuable cathode active materials—often in very small amounts. The challenge lies in maximizing impurity removal while keeping these losses to an absolute minimum.

The composition of input batteries vary in materials used, leading to fluctuation in process efficiency and separation quality. The goal is to implement adaptive sorting and separation technologies. This could be either technologies where processing parameters can be adapted easily or potentially AI-driven process controls. In any case – pre-sorting batteries by chemistry and processing same batteries in one campaign helps reduce variability and enhance process stability.