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Battery black mass: The metal-rich powder produced from shredding spent batteries
Black mass is a metal-rich, dark powder produced by mechanically processing spent lithium-ion batteries such as those in EVs, e-bikes and smartphones.
This guide explains what black mass is, what it is made from, how it is produced and recycled, the key actors involved, and how the process is regulated in the UK.
Contents:
- What is battery black mass?
- Which batteries produce black mass?
- What is battery black mass made from?
- How is battery black mass produced?
- How is black mass recycled?
- How is battery black mass recycling regulated in the UK?
What is battery black mass?
Black mass is a metal-rich, dark powder produced by shredding, milling and sieving spent or faulty lithium-ion batteries, from devices ranging from EVs to smartphones.
Its exact composition depends on the feedstock batteries, but typically includes lithium, cobalt, nickel and manganese, along with graphite.
It is produced in the UK in modest quantities and largely exported, mainly for the production of new batteries in China and other parts of Asia.
Its production follows the highly regulated end-of-life cycle of spent batteries, starting with their collection, continuing through their transportation, sorting and the removal of non-battery components by licensed parties, before their final mechanical breakdown.
Which batteries produce black mass?
Black mass can be produced from almost any lithium-ion battery, so its feedstock can be variable. The most common types of batteries used as raw material are:
Electric vehicle (EV) batteries
EV battery packs are substantial and the largest and fastest-growing feedstock for black mass by volume.
Their scale means they can have their own dedicated, single-feed process, producing a consistent, high-quality, single-stream black mass.
Each pack can weigh several hundred kilograms, and as the first generation of EVs reach their end-of-life, these packs are becoming the dominant raw material for specialised recyclers.
The chemistry varies by vehicle, with many using nickel- and cobalt-rich formulations, while a growing share relies on cobalt-free lithium iron phosphate (LFP) batteries.
Consumer electronics
Smartphones, laptops, tablets, cameras and other everyday devices all run on small lithium-ion cells, typically built around cobalt-heavy chemistries.
Individually each battery is tiny, but the sheer number discarded every year makes this a significant and remarkably steady stream, albeit of variable cell chemistries.
It is also one of the hardest to capture, as these batteries are frequently sealed inside devices and often end up in general waste rather than being collected for recycling.
Power tools and cordless equipment
Cordless drills, saws, garden tools and similar equipment rely on robust lithium-ion packs designed for high output and repeated heavy use.
They are a common feature of commercial and business waste streams, and their relatively standardised pack format makes them straightforward to feed into the recycling process.
As cordless technology continues to displace corded and petrol-powered tools, the volume reaching end-of-life continues to increase.
Energy storage systems
Home battery units and large grid-scale installations increasingly depend on LFP cells, prized in this setting for their long cycle life and stability.
Their volume as a black mass feedstock is expected to keep increasing as renewable generation and domestic solar storage expand.
However, these chemistries tend to lack cobalt or nickel, so their use as feedstock sits at the lower-value end.
Micromobility batteries
The lithium-ion packs powering electric bikes, e-scooters and similar vehicles are a smaller but rapidly rising source, particularly in towns and cities.
They are recycled through the same process as larger batteries, but yield a poorer-quality feedstock and carry a higher fire risk, which makes their safe collection, storage and recycling a growing priority for waste operators.
What is battery black mass made from?
Black mass is made of the materials that make up a battery’s electrodes (cathode and anode), ground into a fine powder, along with residues of the electrolyte and binders.
Its make-up varies with the types of batteries being recycled, but typically blackmass is composed of the following materials:
| Component | Indicative content (by weight) | Importance |
|---|---|---|
| Cobalt | 0–20% | Often the single most valuable metal present. Scarce, costly and subject to ethical-sourcing concerns, which makes recovered cobalt particularly sought after by manufacturers. |
| Nickel | 0–20% | A major driver of black mass value, especially from EV battery feedstock. Demand is closely tied to electric vehicle growth, though the rise of cheaper cobalt- and nickel-free LFP cells is tempering it. |
| Lithium | ~2–7% | The defining metal of the battery and a priority for recovery across every chemistry. Prices have been volatile, but long-term demand is expected to climb sharply as electrification accelerates. |
| Graphite | ~30–50% | Usually the largest portion. Long treated as low-value filler, it is now classed as a critical raw material and increasingly recovered in its own right, as trade tensions and export controls tighten global supply. |
| Manganese | 0–10% | Lower value than nickel or cobalt but still worth recovering, and a steady presence in the widely used NMC chemistry. |
| Copper & aluminium | ~5–15% | Carried over from the battery's internal foils during shredding. Recoverable in their own right, but within black mass they are usually treated as contaminants to be separated out. |
| Binders, electrolyte & other residues | ~5–15% | The remaining fraction, made up of salts, polymers and additives. These hold little recovery value and are removed as impurities during refining. |
How is battery black mass produced?
Black mass production starts with the disposal and collection of a spent battery and ends with a refined powder ready to be shipped on for metal recovery.
Here it is, step by step:
1. Collection of spent batteries
Spent batteries are collected in various ways in the UK, depending on the type of battery, the volume involved, and for households, the council they fall under. The main options, ranked by volume contribution, are:
- Producer take-back (EV & industrial): Spent automotive and industrial batteries follow a tightly controlled route through authorised treatment facilities, with free producer take-back and Environment Agency tracking.
- Commercial waste collection: Businesses that generate substantial volumes of spent batteries, such as power tools, e-bike fleets and industrial cells, arrange collection through licensed waste providers.
- Household waste recycling centres: Council tips take batteries alongside bulkier items, so they gather a meaningful share of the larger household batteries as well as everyday ones.
- In-store take-back (drop-off): Shops selling above a set volume of batteries must provide spent battery drop-off tubs (note that these are separate from electronic waste tubs), such as those found in supermarkets and electronics stores. The network is widespread, but it mostly gathers small, low-weight cells.
- Kerbside collection: The council picks batteries up from the doorstep on normal bin rounds. Only around a quarter of councils offer it, reaching roughly 23% of households, and it captures mostly small portables.
- Recovered from electronic waste: Although not a collection route itself, many spent batteries come from the electronic waste stream (WEEE), as they are manually removed during treatment and diverted into the battery stream.
2. Transporting, sorting, testing and second-life triage
Batteries collected from mixed-battery streams (e.g., drop-off points, kerbside collection) are transported by licensed waste carriers, since they are classed as hazardous waste.
They are taken to sites run by licensed treatment operators, known as ABTOs, because spent batteries cannot legally be handled by a general waste contractor.
At these sites, they are sorted, screened and assessed:
- Sorting by chemistry: At dedicated, permitted facilities, batteries are separated by type, since lithium-ion, lead-acid and alkaline cannot be processed together. This is done by hand or, increasingly, by automated commercial recycling technologies such as optical and X-ray systems.
- Safety screening: Damaged, swollen or leaking cells are set aside for specialist handling, as they carry the highest fire risk.
- Second-life triage: Batteries that still hold usable capacity, most often EV packs, may be diverted into “second-life” uses such as energy storage rather than being recycled straight away.
3. Making cells safe to break down
Batteries have to be made safe before they can be physically broken open, as the energy and reactive materials inside them make shredding a fire and explosion risk.
The Environment Agency’s guidance explains this in more detail, but typically two approaches exist depending on the type of battery:
- Large batteries (EV, industrial & storage): Tested individually and, where needed, discharged early, before dismantling and sometimes even before transport, since a high-charge pack holds a dangerous amount of energy and is hazardous to move.
- Small portable batteries: Made safe at the shredding stage itself by doing so under inert gas, under vacuum, or submerged in water, so that charged cells cannot ignite.
4. Dismantling (For larger batteries)
Larger batteries, especially EV and industrial packs, are dismantled down from pack level into modules and individual cells.
This stage separates out the high-value structural components (i.e., wiring, casings and battery management electronics) and prepares the cells for shredding by removing unwanted parts.
Small portable batteries arrive separate from their original devices as these were removed upstream (either handed over as loose cells, or extracted from electronic waste during treatment).
5. Mechanical processing into black mass
The stream of dismantled bare cells (the feedstock) then goes through a shredding, milling, sieving and separation process to produce black mass:
- Coarse shredding: The cells are broken open by a slow, high-torque shredder into fragments of a few centimetres. When the feedstock is mixed, this is done under inert gasses, vacuum or immersion to avoid fire and explosion risk. The electrolyte released at this point is captured and drawn off for treatment.
- Size reduction: The fragments are milled down further, which frees the fine electrode powder from the metal foils and plastics it was coated onto. This liberated powder is the black mass.
- Sieving: The milled material is screened by particle size. The fine fraction that passes through is largely black mass; the coarser fraction holds the foils, casing and plastics that need further separation.
- Magnetic separation: Magnets pull out the ferrous metals, chiefly the steel from casings.
- Eddy current and density separation: The remaining non-ferrous fractions are split apart, using eddy current separators and density-based methods to recover the copper and aluminium foils and remove the lighter plastic separators.
How is black mass recycled?
Black mass is a valuable, imperishable, transportable material, but it requires further processing to become the raw metals necessary for manufacturing new products.
This process is called refining, and there are three principal routes:
Hydrometallurgy
This is the dominant method industrially, and the one most new plants are built around. The black mass is dissolved in acids to produce a metal-rich solution, from which lithium, cobalt, nickel and manganese are selectively extracted and precipitated out as salts or hydroxides.
Its appeal is recovery and purity, with modern hydrometallurgical facilities able to recover up to 95-99% of critical metals such as cobalt and nickel, and capturing a significant portion of the lithium. It also runs at relatively low temperatures, so it uses less energy than smelting.
The trade-off is that it produces significant amounts of troublesome chemical waste which needs to be disposed of.
Pyrometallurgy
The traditional, more established route, based on heat. The black mass is smelted at high temperature, which melts the metals into an alloy that can then be separated.
Its appeal is robustness, since it is a simple process that handles mixed, variable feedstock with little sorting.
However, it is energy intensive, produces greenhouse gases, and the high temperatures mean lithium and manganese are largely lost into the slag, where recovering them is uneconomical.
Direct recycling
This is an emerging route which aims to recover and repair the cathode more or less intact, so it can be reused with far less reprocessing.
It only works with controlled inputs ( a clean, well-sorted, single-chemistry feedstock) and is still largely at pilot and demonstration stage.
How is battery black mass recycling regulated in the UK?
Battery recycling is highly regulated because of the fire, chemical and environmental risks involved.
The chain runs from the companies that first sell batteries, through the businesses that collect, transport and process them, to those that export the resulting material abroad.
The key rules for each actor are:
- Producers: The businesses that place batteries on the UK market, whether selling batteries themselves or products containing them (from phones to power tools to EVs). They carry the legal and financial duty to fund the collection and recycling of those batteries once they become waste, under current waste regulations.
- Businesses producing battery waste: Any business that generates spent batteries, including commercial operators clearing them from a site, must classify the waste correctly and use only registered carriers and permitted sites to move and treat it.
- Waste carriers: The operators who collect and transport spent batteries. They must be registered as licensed waste carriers, cannot pass batteries to a general waste contractor, and must move them under ADR dangerous-goods rules.
- Treatment operators: The permitted sites that sort, treat and recycle the batteries into black mass. Any such site must be an Approved Battery Treatment Operator (ABTO) holding an environmental permit; sorting alone counts as treatment in law, so even separating batteries by chemistry falls under this.
- Exporters: The operators who ship batteries or black mass abroad for refining, which is where much UK material currently goes. They must be an Approved Battery Exporter (ABE) and comply with international waste export and shipment controls.
Black mass recycling FAQs
Our business waste experts answer commonly asked questions regarding black mass production and recycling:
Is battery black mass hazardous?
Yes, black mass contains reactive metals and residual electrolyte, making it flammable and potentially harmful to health and the environment, and it is generally handled as hazardous waste.
Can black mass be used to make new batteries?
Yes, because it yields the raw materials necessary to make batteries. Once refined, the metals recovered from black mass (lithium, nickel, cobalt and manganese) are turned into battery-grade salts and compounds that go straight back into manufacturing new cathodes and cells.
Can battery manufacturing scrap be processed into black mass?
Yes, and it is currently the largest source. Battery factories generate substantial offcuts and reject cells (typically around 8–10% of production), which are much easier to recycle than end-of-life batteries.
Industry analysts expect manufacturing scrap to remain the primary feedstock for black mass until end-of-life EV batteries catch up in the mid-2030s.
Does black mass have a standard specification or grade?
Not in the way exchange-traded metals do. Its composition varies with the batteries it came from, so every batch is assayed (chemically analysed) and traded on its measured metal content rather than to a fixed grade.
Buyers pay on a “payable” basis, receiving a percentage of the value of the contained metals, and cleaner, higher-grade, single-chemistry black mass commands a premium over mixed, contaminated material.
What are the core problems when recycling black mass?
Several challenges shape the industry, namely:
- Feedstock is variable, as mixed chemistries complicate processing and pricing.
- It carries genuine fire and safety risks at every stage.
- Refining is chemically intensive and, for the UK, largely absent domestically, so material is exported.
- The economics are volatile, rising and falling with battery-metal prices.
- There is a global feedstock shortage, with refining capacity having grown faster than the supply of batteries reaching end of life.
Can graphite recovered from black mass be reused in new battery anodes?
In principle yes, though it is harder than recovering the metals.
Graphite is often the largest fraction of black mass and is now classed as a critical material, but reusing it in anodes demands very high purity, and residual metals and binders are difficult to remove.
Research has produced recycled graphite performing on par with virgin material, but commercial battery-to-battery graphite recycling is still emerging; much recovered graphite currently goes to lower-grade industrial uses instead.
Can black mass be transported between countries for refining?
Yes, and much of it is. Because the UK and Europe can produce black mass but have limited refining capacity, a large share is shipped abroad (principally to South Korea, with China reopening to imports and Southeast Asia emerging as a hub).
As hazardous waste, these movements are tightly controlled under international waste-shipment rules, and only Approved Battery Exporters may carry them out.
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