As more electric trucks, SUVs, and sports cars are introduced to the market, the size and quantity of battery packs required to power them grow.
To achieve a power output of 170 to 215 kWh, battery packs typically contain over 1,000 individual cells, some of which, but not all, are grouped into dozens of modules. To put this into perspective, these vehicles’ largest commercial battery packs are comparable to a king-sized mattress and can weigh nearly 2,000 pounds.
Large battery packs of this scale pose considerable challenges when attempting to recover valuable materials during recycling, starting with the difficulties of lifting and integrating them into conventional battery recycling systems.
When this happens, recyclers must break down large packs into smaller components. However, this process is highly challenging because potting materials secure the components into a solid structure. This makes it difficult to cut, dissolve, or separate the pack into parts without causing damage. Attempts to do so risk puncturing or harming the cells, potentially leading to fire or thermal runaways that cannot be extinguished.
Just the act of shredding batteries that have not been fully discharged can introduce joules of energy into the system. Simply put, managing the immense heat and energy that can be released during recycling presents considerable technical challenges that must be addressed.
Experts in battery recycling highlight the need for a comprehensive, turnkey solution designed to safely and efficiently shred the largest commercial electric vehicle (EV) battery packs on the market without having to discharge the battery first. Fortunately, there’s a solution (Figure 1).
Figure 1. Battery recyclers require a specialized system that can safely and efficiently process large commercial EV battery packs without prior disassembly or discharge, optimizing material recovery and safety.
Advanced systems are now capable of processing large battery packs without the need for disassembly or discharge. Designed to integrate seamlessly as the “front end” of existing recycling processes, these systems are already in use by some of the world’s largest EV manufacturers. Production is currently underway in Germany, the UK, and the US.
These large battery pack systems allow EV manufacturers and major recyclers to efficiently and safely recover valuable ferrous metals and battery-grade black mass. This process extracts a complex mix of metals — including lithium, cobalt, nickel, and manganese — which can then be refined into precursor cathode active material (pCAM) through hydrometallurgical methods by the recycler or third-party black mass buyers.
Overcoming challenges
Safe shredding of large battery packs comes with considerable safety and processing challenges. Through extensive research, design, and production testing, at least one fully sealed system has been engineered incorporating a water-nitrogen blanket, lift-and-dump mechanism, three-part progressive shredding, air, and water treatment system, along with other unique design features.
The hydro-nitrogen “large pack” battery recycling systems can safely process anything from multiple smaller packs and modules to whole battery packs used in electric trucks and SUVs (Figure 2). Some of the largest EV manufacturers and recyclers use this system to process battery packs measuring 70” x 118” 15” and weighing over 1,700 pounds.
Figure 2. Large battery pack systems enable EV manufacturers and major recyclers to efficiently and safely recover valuable ferrous metals and battery-grade black mass that can then be refined by the recycler or third-party buyers.
A water and nitrogen-based environment regulates thermal activity throughout the shredding process, submerging EV battery packs to suppress or significantly reduce energy release, with most VOCs remaining in the water solution.
An inert nitrogen atmosphere prevents thermal runaway by reducing available oxygen concentration, which is crucial for combustion and fire propagation within a battery experiencing thermal runaway. This method can effectively “smother” the reaction and prevent it from escalating further.
Since the recyclable Li-ion battery black mass material does not readily absorb water, it can cool materials and extinguish potential fires.
Combined with nitrogen, this method controls and eliminates thermal events through a wet process. While pouch-style batteries contain water-absorbent materials, a system of this nature has been designed to accommodate these variations. This approach also enhances processing speed compared to dry systems, often presenting greater safety and air quality concerns.
A water and airtight system has been developed to accommodate lithium batteries of this size, density, and energy output. Since shredders are typically not designed for complete submersion in water, specialized seals and stainless-steel chamber liners have been incorporated into the primary shredder, allowing for either full submersion of the batteries or a robust spray system.
Loading tech
Whole charged packs up to 72 inches (6 feet) wide and 3,000 pounds are fed into the submerged primary shredder using a hydraulic dumper lift. The lift is designed to seal against the surface of the first chamber, open a tailgate, and slide the battery pack into the primary shredder.
The lift-and-dump mechanism is nonconductive, preventing electrical-thermal reactions that could occur if a battery were moved over metal rollers.
Progressive shredding
Breaking down large battery packs involves a three-step shredding process, which reduces individual battery cells to 5/8-inch discharged material while safely dispersing the stored energy into the system without effluent. This gradual shredding method ensures that all battery cells are entirely and effectively cut.
In primary shredding, processing dense, heavy ferrous metals requires larger, more durable knives. Thin knives are prone to deflection under the density of these materials, which can lead to blades rubbing against each other, ultimately causing damage or dulling the knife system.
Figure 3. Precision knife technology enhances wet battery recycling by ensuring uniform material reduction in a single pass.
Following the initial shredding process, EV battery materials are transferred to secondary and tertiary shredders equipped with airlocks and specially designed water-filled augers.
At a further secondary stage, progressively thinner knives are used to achieve the specified final material output and separation of metals, plastics, and remnant black mass. Knife technology tailored for wet battery recycling ensures materials are reduced to a consistent and uniform size in a single pass without screening.
A system like this is adaptable, allowing for processing smaller packs or modules as needed. Throughput is maximized because the shredding system can adjust to the demands of each load. This is accomplished using variable displacement hydraulics that can run between 9 and 28 RPM, changing quickly based on the hydraulic load.
Material recovery
A large-pack Li-ion reduction system of this nature processes entire EV packs to shippable, manageable 5/8-inch inert material, separating black mass and, with additional equipment, ferrous materials as well as non-ferrous metals such as copper and aluminum.
Recycling specialists indicate that the system can recover approximately 60% of the black mass, which is considered valuable due to the high demand for lithium, cobalt, and nickel to manufacture new batteries. However, additional secondary equipment can be incorporated to achieve a black mass separation rate of up to 95%.
A well-designed closed wet battery recycling system can capture black mass more effectively and at a much-improved purity level, enhancing its value and usability.
Figure 4. Battery pack recycling systems should incorporate fully automated, variable-speed control, allowing adjustments based on hydraulic load for optimized processing efficiency and safety.
All other particles besides the black mass are substantial, so it’s relatively easy to filter, press out, dewater, and dry. The result is an extremely clean, sellable black mass.
For industry professionals who need to safely and efficiently reclaim valuable materials from even the largest EV battery packs to increase profitability, adding a modular large-pack Li-ion reduction system to their existing process will likely become the best practice.
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