The mechanical decomposition method, with its unique physical processing approach, has demonstrated certain advantages and disadvantages in the field of used lithium battery recycling. The following is a detailed analysis of the pros and cons of this method:
Notable Advantages
Prominent Environmental Characteristics
The mechanical decomposition method mainly relies on physical means to process batteries, without the need for large amounts of chemical reagents. This significantly reduces the generation of wastewater and waste gas. Compared with wet recycling, its pollution risk is reduced by approximately 40%. Moreover, this method can directly separate materials such as plastics, copper, and aluminum for direct recycling, effectively reducing resource waste.
High Recycling Efficiency
With the aid of intelligent sorting technology, the recovery rate of iron-based materials can reach over 98%, and the purity of copper and aluminum metals can reach 99.6%. For positive and negative electrode materials, electrostatic separation technology is used, achieving a recovery rate of key metals exceeding 92%. If combined with hydrometallurgy, the recovery rate of lithium can reach as high as 98.5%.
Low Processing Cost
The mechanical method has a relatively simple process, mainly including crushing and sorting steps. The maintenance cost of the equipment is 30% - 50% lower than that of the chemical method. Additionally, its processing speed is fast. For example, equipment certified by the EU CE can process up to 5 tons per hour, making it highly suitable for large-scale industrial production.
Good Safety Performance
During the pre-treatment stage, deep discharge technology (such as resistance discharge boxes) is used, reducing the risk of battery short circuits by 63%. Moreover, the use of laser cutting or mechanical fixtures to remove the casing effectively avoids the risk of electrolyte leakage that may occur during manual disassembly.
Limitations
Incomplete Material Separation
The mechanical method cannot separate metals such as lithium and cobalt in the electrode coatings, requiring subsequent extraction through chemical leaching. Additionally, plastic separators can produce micrometer-sized debris during the crushing process, which can affect the purity of metal separation to a certain extent.
Poor Adaptability to Battery Types
Different types of batteries have significant structural differences, and the mechanical method requires frequent mold changes, reducing production efficiency.
Safety Risks
If the discharge is not thorough, short circuits may occur during the crushing process, potentially causing fires. Residual electrolytes may also release harmful gases such as HF, thus requiring a corresponding exhaust gas treatment system.
High Equipment Investment Cost
High-precision sorting equipment can cost over 2 million yuan per unit, and wear-resistant parts need to be replaced regularly, incurring certain maintenance costs.
The mechanical decomposition method in lithium battery recycling is characterized by its environmental friendliness and high efficiency, making it a core technology for large-scale battery recycling. However, it needs to be combined with chemical methods to fully extract the value of precious metals in batteries. When choosing a recycling process, enterprises should consider the economic and environmental aspects based on their production capacity and technical conditions.
