Spent batteries enter a shredder, then pass through magnetic and density-based separators that sort shredded "black mass" into recoverable material streams (lithium/cobalt/nickel compounds, steel, plastics).
recovered = Σ mass_i · sortEfficiency_i
E_used ∝ throughput · shredderSpeed²
CO2_avoided ∝ recovered_metal_mass
- Throughput — batteries fed into the line per second; more throughput needs more shredder/separator energy.
- Sorting efficiency — how cleanly the separators split materials; higher efficiency recovers more usable material per battery.
- Shredder speed — faster shredding increases energy draw roughly with the square of speed (kinetic energy).
- Mechanical / Hydrometallurgical toggle — mechanical shredding is fast and low-energy but recovers coarser material; the hydrometallurgical route dissolves black mass chemically for higher-purity, higher-value recovery at more energy cost.
Real application: recycling plants recover 80-95% of a lithium-ion battery's cobalt and nickel this way, cutting demand for newly mined ore.