Battery Recycling Claims Need Black-Mass Chain-of-Custody
Lithium-ion battery recycling is often described as a circular-economy win: spent batteries become critical minerals for new batteries. That description is directionally correct but operationally incomplete. This paper synthesizes U.S. hazardous-waste and transport guidance, EU battery regulation, battery-passport guidance, European black-mass waste-code changes, IEA and USGS mineral evidence, national-lab modeling work, OECD trade analysis, and a peer-reviewed recycling-technology review. The evidence shows that recycling value depends on more than collection volume or nominal recycled content. Batteries must be safely identified, transported, sorted, processed into intermediate fractions such as black mass, assayed, legally classified, and linked to recovery yields and recycled-content claims. The contribution is a black-mass chain-of-custody model that connects safety status, chemistry, processing step, hazard determination, destination, material assay, recovery pathway, and claim boundary. The conclusion is practical: battery circularity claims should be accepted only when the evidence follows the material through the hazardous middle of the recycling chain, not merely from collection event to marketing claim.
Introduction
Lithium-ion batteries are central to electric vehicles, consumer electronics, and stationary storage, and their end-of-life management now sits at the junction of safety, waste law, material security, and circular-economy accounting. EPA says used lithium-ion batteries contain critical minerals needed for new batteries and should be recycled rather than placed in household garbage or municipal recycling streams [[cite:epa_used_lib]]. IEA likewise treats battery recycling as a major future source of metal recovery for lithium, nickel, cobalt, and related minerals [[cite:iea_recycling_critical_minerals]].
The public narrative often compresses that chain into a simple statement: batteries are collected and recycled into new batteries. The evidence base shows a more demanding sequence. End-of-life batteries can be ignitable and reactive hazardous waste; transport is regulated as hazardous-material movement; damaged, defective, or recalled batteries need special treatment; shredded battery intermediates become black mass; and recycled-content claims depend on chemical-element accounting, not only on whether a pack was accepted by a recycler [[cite:epa_lib_recycling,phmsa_transport,battery_pass_guidance]].
This matters because black mass is both valuable and awkward. EPA defines it as a filter-cake-like material made from anode and cathode materials after shredding, while stressing that it is no longer a battery and not universal waste [[cite:epa_lib_faq]]. The European Commission moved in 2025 to classify black mass from batteries as hazardous waste, aiming to control shipments and keep critical raw materials in the European economy [[cite:ec_black_mass_codes]]. The same material can therefore be framed as resource, waste, hazard, trade object, and evidence-bearing intermediate.
This paper asks: what evidence should connect lithium-ion battery recycling claims to the black-mass and recovery steps that make those claims credible? The answer proposed here is a chain-of-custody model for the hazardous middle of battery circularity. The model does not replace legal obligations, transport rules, recycler permits, or battery passports. It specifies the evidence fields that should travel with the material so that safety decisions, recovery accounting, and recycled-content claims remain tied to the same physical stream.
Method
I used a conceptual-synthesis method. The source base combines AlexandrAI graph search, official U.S. and EU sources, international organization reports, national-lab modeling descriptions, one peer-reviewed technology review, and policy analysis on trade and circularity. Searches were conducted on 2026-06-26. Sources were included when they supported one of four questions: how batteries and black mass are classified, what safety controls apply before processing, what recycling and recycled-content claims require, and what evidence gaps prevent reliable circularity claims.
The screening rule favored primary or near-primary sources. EPA, PHMSA, EUR-Lex, the European Commission, IEA, USGS, DOE, ReCell, OSTI, RSC, and OECD sources were full-read. Vendor explainers, law-firm summaries, trade press, and industry position papers were screened for terminology and query expansion but excluded from load-bearing claims when official or peer-reviewed evidence was available.
The synthesis coded each source into chain stages: collection and first handling, transport, safety status, sorting and chemistry identity, black-mass generation, hazard determination, trade or destination control, processing route, recovery yield, recycled-content claim, and passport or product-data link. Claims about legal status, dates, targets, and reported percentages are treated as factual claims tied to cited sources. The chain-of-custody model is an inference from recurring dependencies across those source families.
Recycling claim confidence = f(safety status, chemistry identity, processing step, hazard determination, assay, recovery yield, destination, claim boundary)
Equation (1) is not a numerical estimator. It states the analytic premise: a recycling claim is weak when it identifies only the collection event or the final marketing statement, and stronger when it preserves evidence through the intermediate stages where safety, waste status, chemistry, and yield are determined.
Evidence Boundary
The evidence supports battery recycling as a real critical-minerals strategy, but it also rejects easy accounting. IEA estimates that recycled energy-transition minerals can have much lower greenhouse gas emissions than primary mining routes, and projects that end-of-life EV and storage batteries will become the dominant available battery-recycling feedstock after 2035 [[cite:iea_recycling_critical_minerals]]. At the same time, IEA reports that battery-metal prices fell sharply after recent surges and that low prices can weaken investment signals for new projects [[cite:iea_critical_minerals_2025]]. Recycling value therefore depends on both physical feedstock and market conditions.
Mineral context also matters. USGS Mineral Commodity Summaries 2025 provides comprehensive 2024 production data for more than 90 minerals and materials, which makes it a useful baseline for understanding why recovered lithium, cobalt, nickel, graphite, and related materials attract policy attention [[cite:usgs_mcs_2025]]. But mineral-supply context does not by itself validate any given recycled-content claim. The material must be traced.
The technology literature adds another boundary. The RSC review compares direct recycling, pyrometallurgy, hydrometallurgy, bio-hydrometallurgy, and electrometallurgy, and identifies unresolved issues such as full component recycling, thermal degradation intermediates, and environmental or safety monitoring in high-temperature processes [[cite:rsc_recycling_review]]. A claim that a battery was recycled is therefore incomplete unless it identifies the route and the material fractions actually recovered.
The Hazardous Middle
The hazardous middle begins before a recycler recovers metals. EPA states that most lithium-ion batteries are likely hazardous waste at end of life because they may be ignitable and reactive, and the 2023 RCRA memo says they can be managed as universal waste only until they reach a destination facility for recycling or discard [[cite:epa_lib_recycling,epa_lib_memo]]. EPA also says universal waste handlers may sort, mix, discharge, regenerate, remove batteries from products, and in limited cases remove electrolyte, but may not breach or open lithium cells to shred them into black mass [[cite:epa_lib_faq]].
Transport adds a second boundary. PHMSA states that lithium batteries are hazardous materials under DOT regulations when transported in commerce [[cite:phmsa_transport]]. Its disposal and recycling safety advisory says lithium batteries can cause fires whether new, used, defective, or damaged, and it highlights improper packaging, short-circuit risks, mixing damaged batteries with other batteries, and weak package identification as recurring problems [[cite:phmsa_safety_advisory]]. A chain-of-custody record must therefore capture damage status and packaging controls, not only weight.
Black mass changes the legal and technical object being tracked. EPA says black mass is no longer a battery and not a universal waste; it may or may not exhibit hazardous-waste characteristics, and generators remain responsible for accurate determinations [[cite:epa_lib_faq]]. The European Commission moved in the opposite direction from ambiguous resource framing by classifying black mass from batteries as hazardous waste in the EU waste-code system, explicitly connecting that choice to shipment control and retention of critical raw materials [[cite:ec_black_mass_codes]].
This crosswalk is the core result: chain evidence should attach at every boundary where the governing object changes. A battery pack, universal waste battery, damaged battery, black mass, hazardous black mass, recovered salt, and recycled-content input are not interchangeable labels. They are different evidence states in a material history.
Targets and Passports
EU law gives the clearest public example of why material claims require element-specific evidence. Regulation (EU) 2023/1542 establishes battery lifecycle obligations including producer registration, extended producer responsibility oversight, collection data, and information availability [[cite:eurlex_battery_reg]]. EUR-Lex summarizes recycling-efficiency targets including 65 percent for lithium-based waste batteries by the end of 2025, with higher targets later for some chemistries [[cite:eurlex_battery_summary]]. These are system-level targets, not proof that a particular claim about a particular battery lot is true.
Battery Pass guidance narrows the accounting question. It describes recycled-content targets for cobalt, lead, lithium, and nickel beginning in 2031, and higher cobalt, lithium, and nickel targets in 2036; it also recommends separating pre-consumer and post-consumer recycled-content shares [[cite:battery_pass_guidance]]. That creates a need for evidence about origin, element, manufacturing plant, battery model, and whether material came from manufacturing waste or post-consumer waste.
The prior AlexandrAI DPP paper argued that product passports become useful only when data carriers resolve into governed lifecycle evidence rather than static QR compliance [[cite:archive_dpp_lifecycle]]. The battery-recycling chain extends that logic downstream. A battery passport can identify the product, chemistry, and producer obligations, but recycling accountability needs updates after collection, sorting, black-mass generation, assay, and recovery. The passport is a bridge only if downstream events write back into governed records.
Figure 1 shows why chain evidence becomes more important over time. Manufacturing scrap can be closer to known production processes; end-of-life packs arrive from dispersed use, reuse, accidents, repairs, ownership transfers, and variable state of health. As post-consumer batteries dominate feedstock, the evidentiary burden shifts from factory scrap accounting to reverse-logistics chain-of-custody.
Black-Mass Accountability Model
The proposed model has seven linked records. The first is source identity: device or vehicle class, producer or importer where known, chemistry, and whether the battery is portable, industrial, LMT, EV, or SLI. The second is safety status: damaged, defective, recalled, swollen, leaking, burned, submerged, or unknown. The third is transfer control: handler, packaging, marking, mode, and destination. These three fields prevent a material-value claim from erasing fire and transport risk, and they align with the DOE Blueprint's emphasis on collection, sorting, transport, processing, and pack design for recycling [[cite:epa_used_lib,phmsa_safety_advisory,doe_blueprint]].
The fourth record is processing transformation: sorting, discharge, dismantling, shredding, and black-mass lot creation. The fifth is hazard and assay evidence: waste classification, contaminants, moisture, black-mass composition, and chemistry mix. The sixth is recovery route: direct recycling, hydrometallurgical recovery, pyrometallurgical recovery, combined route, refining destination, output purity, and residual treatment. The seventh is claim boundary: whether the recovered material is counted toward recycling efficiency, material recovery, recycled content, battery passport data, or a voluntary circularity claim [[cite:rsc_recycling_review,battery_pass_guidance]].
The model complements national-lab modeling. ReCell describes EverBatt, GCMat-Bat, and LIBRA as tools for evaluating cost, environmental impact, supply-chain behavior, and material flows across battery lifecycle stages [[cite:recell_modeling]]. The OSTI EverBatt report illustrates why pathway-specific modeling is needed as end-of-life EV batteries grow [[cite:osti_everbatt]]. A chain-of-custody ledger supplies the granular input that such models and compliance systems need.
Discussion
The central implication is that battery circularity should be audited at the hazardous middle, not only at the endpoints. EPA, PHMSA, and the European Commission all locate risk and control obligations before the final recycled-content claim: hazardous-waste status, packaging and damage status, black-mass classification, facility role, and shipment control [[cite:epa_lib_faq,phmsa_safety_advisory,ec_black_mass_codes]]. A circularity dashboard that begins with collection volume and ends with recovered-metal marketing misses the most decision-relevant evidence.
The model also explains why policy instruments are complementary. Universal waste rules can streamline collection and transport to appropriate facilities; hazardous-material transport rules reduce fire risk in motion; EU recycling-efficiency and recycled-content rules create pull for verified secondary materials; battery passports can carry product data; and trade rules affect where black mass can be processed [[cite:epa_universal_waste_proposal,eurlex_battery_reg,battery_pass_guidance,oecd_trade_lib]]. None of those instruments alone proves that a specific recovered element is traceable to a specific waste stream.
There are important limits. First, the paper is a conceptual synthesis, not a measurement of recycler performance. Second, current evidence does not support one universal recycling route: process choice depends on chemistry, contamination, economics, safety, and desired outputs [[cite:rsc_recycling_review]]. Third, IEA projections are scenarios, not guarantees; lower battery-metal prices can weaken investment and make some recycling claims less robust economically [[cite:iea_critical_minerals_2025]]. Fourth, EU black-mass classification and recycled-content rules do not automatically govern every jurisdiction, and U.S. black-mass hazard status remains characteristic-dependent under EPA interpretation [[cite:epa_lib_faq,ec_black_mass_codes]].
The recommended practice is therefore modest but concrete. Require chain-of-custody evidence whenever recycled battery material is used to support a public claim, procurement criterion, compliance report, passport entry, or critical-minerals strategy. The record should preserve what the material was, how it was moved, when it became black mass, how it was classified, what it contained, how it was processed, what was recovered, and what fraction was not recovered.
Conclusion
Lithium-ion battery recycling can reduce waste risk and contribute to critical-minerals supply, but only if the evidence follows the material through its hazardous middle. A collected battery is not yet recovered lithium. A black-mass shipment is not yet a recycled-content claim. A battery passport is not yet a recovery ledger unless downstream events update it.
The black-mass chain-of-custody model gives a practical accountability test: identify the battery, record safety status, control transport, document facility transformation, assay black mass, classify hazard status, track recovery route and yield, and state the claim boundary. When those links are present, recycling claims become inspectable. When they are absent, circularity may be more story than evidence.