On May 24, 2023, the EPA issued guidance for correctly applying hazardous waste and recycling regulations in the disposal of lithium-ion batteries.
These types of batteries are used in cars, electronics, lawnmowers, e-scooters, electric bicycles, and many other devices, and usage of these types of batteries continues to increase.
“The growth of the circular economy for lithium battery materials is vital as the focus turns to how to eventually manage lithium-ion batteries at the end of their lives. Recycling lithium-ion batteries returns valuable critical minerals to the economy, both conserving resources and reducing the overall energy use needed to produce new batteries,” states the guidance.
The typical structure of a lithium-ion battery cell includes an anode layer, a cathode layer, and a separator, all of which are in contact with an electrolyte, which is most often a liquid. These components are stacked or rolled together and placed in an outer packaging—either a steel can or an aluminum/polymer pouch material is common.
Common materials used in these batteries are lithium, nickel, cobalt, manganese, graphite, iron, copper and aluminum foils, and an electrolyte that’s frequently flammable and classified as an ignitable under the Resource Conservation and Recovery Act (RCRA).
“According to the United States Geological Survey’s 2022 list, of these commonly used materials, aluminum, lithium, nickel, cobalt, manganese, and graphite are all critical minerals,” the guidance notes.
“Despite all these variations, EPA has determined that most lithium-ion batteries on the market today are likely to be hazardous waste when they are disposed of due to the ignitability (D001) and reactivity (D003) characteristics,” according to the guidance. “Fires at end of life are common and mismanagement and damage to batteries make them more likely.”
So, while the EPA classifies these types of batteries as hazardous waste under RCRA, they “can be managed as ‘universal waste’ under 40 C.F.R. Part 273, which imposes a more ‘streamlined’ set of requirements than the standard set of hazardous waste requirements,” says a Loxology article by Covington & Burling LLP. “These determinations will have a significant impact on entities who dispose of lithium-ion batteries, as well as entities involved in battery end-of-life management activities, including recycling.”
Recycling guidance
End-of-life collection of lithium batteries often falls to retailers, storefront recyclers, IT asset dispositions firms, auto dealerships, or auto repair shops.
In all cases, batteries must be identified and sorted for proper recycling and may change hands several times in the process, getting shipped to other collection facilities before arriving at a processing facility.
Larger battery packs can be partially disassembled at any time in this process into cells or modules to facilitate transportation, storage, and processing.
Some battery packs or modules are evaluated for repair or reuse. For example, some companies are experimenting with repurposing used electric vehicle batteries for stationary energy storage. One or more underperforming modules may be replaced in battery packs that can be repaired before being put back into use in the original or another appropriate application.
Batteries slated for recycling are often pretreated or shredded. Depending on the size of the shredding equipment, part or all of the battery is shredded. In some cases, a portion of a device containing a battery may also be shredded. Shredding operations create several different streams, including the following:
- Black mass, a filter, cake-like material made up of the shredded cathodes and anodes of the batteries;
- Copper and aluminum foils onto which anodes and cathodes are coated;
- Separators;
- Plastics;
- Steel canisters; and
- Electrolytes.
“Black mass contains the materials that can be further processed to be made into new battery cathode and anode powders,” according to the EPA guidance. “Although the term ‘black mass’ is commonly used, as of today, there are not industry specifications for black mass and, depending on the inputs and the shredding process employed, there can be wide variation from site to site in the exact make-up and amount of liquid in this material. Black mass is frequently then sent to another facility for metals recovery and may be exported for this purpose.”
Other output materials, such as foils and steel canisters, may also be recycled through separate, dedicated pathways.
There are currently two main methods to recover the metals out of black mass:
- Pyrometallurgical recycling
- Hydrometallurgical recycling
Pyrometallurgy is defined as a “process or technique of refining ores (or recovered material) using heat to melt the metallic and burn the non-metallic content.” Hydrometallurgy is defined as a “process or technique of extracting material at ordinary temperatures by leaching ores (or recovered material) with liquid solvents.”
In some cases, pyrometallurgy can also be used to recover metals from batteries without an initial shredding step. Generally, pyrometallurgical recycling can recover cobalt and nickel, but it would take additional steps to recover other critical materials like lithium from the slag.
Those working in hydrometallurgical recycling technologies tout its ability to economically recover high amounts of cobalt, nickel, lithium, and manganese at the pilot scale and are working to commercialize their recycling technology more broadly, the guidance says.
After metals recovery, to complete the recycling process, the recycled materials can then be made into precursor cathode active materials (pCAM) and, finally, cathode active materials (CAM), which can go into manufacturing new lithium-ion batteries.
Direct recycling
Cathode-to-cathode recycling is known as direct recycling. The process saves energy by preserving the highly engineered cathode structure that’s the most valuable part of the lithium-ion battery and reducing the amount of manufacturing needed to return the materials to pCAM or CAM grade.
“Commercial-scale metals recovery recycling plants in the U.S. are still in development at the time of this memorandum, but multiple facilities are expected to be opening in the next few years, rapidly expanding domestic opportunities for recycling of lithium-ion batteries at end of life,” the guidance continues.
Recycling regulation advice
“EPA’s guidance clarifies that battery recycling facilities generally do not need to obtain RCRA permits in order to conduct recycling operations,” advises Covington & Burlington. “However, EPA cautions that recyclers may not ‘store’ batteries prior to recycling them without obtaining a RCRA permit. EPA declines to specify a permissible ‘holding time,’ which would not be deemed storage, prior to recycling commencing and instead leaves that determination to the regions or the states. EPA also explains that certain RCRA air emission requirements may apply to such operations, and that such operations must comply with the general recycling requirements at 40 C.F.R. § 261.6.
“As EPA notes, most states have delegated authority to implement their own RCRA programs and can impose more stringent requirements. Accordingly, generators, recyclers, and others who manage lithium-ion batteries at the end of their lives should carefully evaluate potential state requirements. Given the increased focus on the recycling of lithium-ion batteries, EPA and the states are likely to increase their compliance and enforcements efforts in this area, and so companies should take appropriate steps to ensure they remain in compliance.”