Hydrometallurgical Battery Recycling: The Critical Link in Circular Battery Supply Chains
Hydrometallurgy has emerged as the dominant process route for recovering high-purity cathode metals from spent lithium-ion batteries. Unlike pyrometallurgy, which smelts batteries at extreme temperatures and typically loses lithium to slag, hydrometallurgical processes dissolve electrode materials in aqueous solutions—enabling selective extraction of lithium, nickel, cobalt, and manganese at recovery rates exceeding 95%.
Global Capacity and Market Structure
Global lithium-ion battery recycling capacity reached approximately 1.6 million tonnes annually in 2025, with hydrometallurgical plants accounting for a growing majority of new capacity additions. China dominates with roughly 70% of global capacity, driven by companies like Brunp (CATL), GEM, and Ganfeng Lithium. Europe follows at ~200,000 tonnes, with Fortum, Umicore, and Northvolt-affiliated Revolt Ett among the leading operators. North America sits at ~144,000 tonnes, anchored by Redwood Materials, Li-Cycle, and Aqua Metals.
| Region | Estimated Hydro Capacity (2025) | Key Players |
|---|---|---|
| China | ~800,000+ t/yr | Brunp/CATL, GEM, Ganfeng Lithium, Huayou Cobalt |
| Europe | ~120,000 t/yr | Fortum, Umicore, Revolt Ett (Northvolt), SungEel HiTech (Hungary) |
| North America | ~80,000 t/yr | Redwood Materials, Li-Cycle, Aqua Metals, ABTC |
| Rest of Asia-Pacific | ~60,000 t/yr | SungEel HiTech (Korea), Dowa (Japan), TES (Singapore) |
Process Variants and Technology Differentiation
Not all hydrometallurgical plants are identical. The core process—acid leaching of black mass followed by solvent extraction and precipitation—varies significantly in implementation:
- Conventional Hydro (acid leaching + SX/precipitation)
- Used by Brunp, GEM, and most Chinese operators. Sulfuric acid leaching with H₂O₂ as reductant, followed by co-extraction of Ni/Co/Mn and selective lithium recovery via carbonate precipitation.
- Electro-hydrometallurgy
- Aqua Metals\u2019 Li AquaRefining process replaces chemical precipitation with electrochemical deposition, producing battery-grade metals directly from solution with lower reagent consumption.
- Hybrid Pyro-Hydro
- Umicore\u2019s approach smelts batteries first (pyro step) to produce a Ni-Co-Cu alloy, then uses hydrometallurgy to refine individual metals. Trades lithium recovery for higher throughput on mixed-chemistry feeds.
Expansion Wave: 2025–2028
The industry is undergoing a massive capacity buildout driven by EU Battery Regulation mandates (minimum recycled content thresholds from 2031), US IRA incentives, and China\u2019s growing wave of first-generation EV battery retirements. Notable expansions include:
- Umicore — 150,000 t/yr European mega-plant targeted for 2026
- Fortum — Harjavalta expansion from 3,000 to 28,000 t/yr (black mass), with a long-term goal of 200,000 t across Europe by 2030
- Redwood Materials — South Carolina campus for integrated recycling + cathode/anode manufacturing on 600+ acres
- Ganfeng Lithium — New 100,000 t facility commissioned in Xinyu, Jiangxi; total capacity reaching 200,000 t
- GEM — 100,000 t NMC plant in Sichuan + 50,000 t LFP-dedicated plant
Key Metrics for Procurement Due Diligence
When evaluating hydrometallurgical recyclers as supply chain partners, EV OEMs and cathode manufacturers typically assess:
- Metal recovery rates — Best-in-class plants achieve >99% for Ni/Co/Mn and >96% for Li
- Output purity — Battery-grade sulfates (Ni ≥22%, Co ≥20%) vs. intermediate products requiring further refining
- Feedstock flexibility — NMC-only vs. multi-chemistry (NMC + LFP + NCA)
- Traceability and chain-of-custody — Increasingly required under EU Battery Passport regulations
- Wastewater and reagent management — Acid neutralization costs and environmental permitting status