Most types of batteries can be recycled. However, some batteries are recycled more readily than others, such as
lead–acid automotive batteries (nearly 99% are recycled) and
button cells (because of the value and toxicity of their chemicals).
Rechargeable nickel–cadmium (NiCd),
nickel–metal hydride battery (NiMH), lithium-ion (Li-ion) and nickel–zinc (NiZn), can also be recycled. Disposable alkaline batteries make up the vast majority of consumer battery use, but there is currently no cost-neutral recycling option. Consumer disposal guidelines vary by region. An evaluation of consumer alkaline battery recycling in Europe showed environmental benefit but at significant expense over disposal.
Lead–acid batteries Lead-acid batteries include but are not limited to:
car batteries,
golf cart batteries,
UPS batteries, industrial forklift batteries,
motorcycle batteries, and commercial batteries. These can be regular
lead–acid, sealed lead–acid,
gel type, or
absorbent glass mat batteries. These are recycled by grinding them, neutralizing the acid, and separating the polymers from the lead. The recovered materials are used in a variety of applications, including new batteries. The lead in a
lead–acid battery can be recycled. Elemental
lead is toxic and should therefore be kept out of the waste stream. The casing of a
lead–acid battery is often made of either
polypropylene or
ABS, which can also be recycled, although there are significant limitations on
recycling plastics. Many cities offer battery recycling services for lead–acid batteries. In some jurisdictions, including
U.S. states and
Canadian provinces, a refundable deposit is paid on batteries. This encourages recycling of old batteries instead of abandonment or disposal with household waste. Businesses that sell new
car batteries may also collect used batteries (or be required to do so by law) for recycling. A 2019 study commissioned by battery-industry promotional group, the
Battery Council, calculated battery lead recycling rates in the United States in the period 2014–2018, taking into account battery scrap lead import/export data from the
Department of Commerce. The report says that, after accounting for net scrap battery lead exports from the United States, 99.0% of the remaining lead from lead-acid batteries in the United States is reclaimed. The
Battery Council figures indicate that around 15.5 billion pounds of battery lead was consumed in the USA in that period, with a net amount of approximately 2 billion pounds battery scrap lead being exported. Of the 13.6 billion pounds remaining after exports, 13.5 billion pounds were recycled. The U.S.
Environmental Protection Agency (EPA), has reported lesser and varying levels of lead-acid battery recycling in the United States in earlier years, under various administrations, Republican and Democrat. The EPA reported in 1987 that varying economics and regulatory requirements have contributed to rates of 97 percent in 1965, above 83 percent in 1980, 61 percent in 1983, and around 70 percent in 1985. According to a 1992 EPA
Superfund report, lead batteries account for about 80% of the lead used in the United States, of which about 60% is reclaimed during times of low lead prices, but more in times of high lead prices; it reported that 50% of the nation's lead needs are filled from recycled lead.
Silver-oxide batteries Used most frequently in watches, toys, and some
medical devices,
silver-oxide batteries contain a small amount of
mercury. Most jurisdictions regulate their handling and disposal to reduce the discharge of mercury into the environment. Silver oxide batteries can be recycled to recover the mercury through the use of both
Hydrometallurgical methods and
pyrometallurgical methods. More recent silver oxide batteries no longer contain mercury and the process of recycling them does not give cause for concern for releasing mercury into the environment. They contain lithium and high-grade
copper and
aluminium. Depending on the active material, they may also contain
cobalt and
nickel. Many products use lithium-ion batteries from
electronics and handheld power tools to
electric vehicles (EVs) and electrical energy storage systems. To prevent a future shortage of cobalt, nickel, and lithium and to enable a sustainable life cycle of these technologies, recycling processes for lithium batteries are needed. These processes have to regain not only
cobalt,
nickel,
copper, and aluminium from spent battery cells, but also a significant share of lithium. Other potentially valuable and recoverable materials are graphite and manganese. Recycling processes today recover approximately 25% to 96% of the materials of a lithium-ion battery cell. In order to achieve this goal, several
steps are combined into complex process chains, while ensuring safety. These steps are: • Metal recovery processes (including
hydrometallurgical processes,
pyrometallurgical processes, or direct recycling) It is expected that a market for lithium recycled from batteries will exist by 2040, and this could add pressure on
hard-rock lithium mining which produces relatively expensive lithium compared with lithium from
brines.
Lithium mining in Australia is in particular expected to be negatively impacted.
Pyrometallurgical method Similar to hydrometallurgical methods, the primary aim of most pyrometallurgical recycling processes is the recovery of valuable minerals (especially Li, Co, and Ni) from the cathode electrode. Thus, the first step is frequently the separation of the cathode material from the rest of the cell components (such as polymer binders, organic electrolyte solutions, and aluminum foil current collectors). In typical pyrometallurgical processes, this separation step can be divided into two categories: incineration (burning organic components in an oxygen rich environment) and pyrolysis (decomposition of organic components without oxygen). While incineration generally requires lower temperatures and shorter times than pyrolysis, pyrolysis offers the advantage of lower CO/CO2 emissions and the potential to recover some organic compounds (such as fluorine containing electrolytes) by capturing and processing the off-gases. After decomposing the organic components of the cell, the remaining cathode material can either be separated from the Al current collector for roasting or the cathode and current collector can be used together for smelting. However, while pyrometallurgy produces less hazardous waste than hydrometallurgical processes, it suffers from both high capital costs and high energy use, as well as substantial process-related CO2 emissions. This is distinct from existing hydro- and pyrometallurgical methods, which break down the cathode into precursors and require subsequent processing to regenerate cathode materials. Maintaining the cathode structure represents an important increase in efficiency, since it produces a higher-value product than other recycling methods. Identifying safer solvents which can effectively separate the black mass is a topic of current research. Compared to direct recycling, this method does not directly look to correct for structural defects in the cathode active material (CAM), such as the formation of inactive crystal structures, the trapping of lithium, or microfractures, but introduces additional lithium into the anode active material, correcting lithium deficiencies. This method does not require the complete disassembly of batteries but does require the exchange of electrolytes into and out of the cell, which would require a change in how cells are treated at a packaging level to accommodate for this. Due to the limited scope of correction that in-situ regeneration can make, it works well with materials whose degradation mechanism is often through the loss of trapped lithium such as lithium iron phosphate (LFP). One such regeneration method is the use of LiSO2CF3 dissolved in electrolyte, which decomposes as follows during charging: Li+(aq) + SO2CF3− (aq) → Li (in anode) + SO2 (g) + C2F6 (g) However, lithium extraction from Li-ion batteries has been demonstrated in small setups by various entities and
Redwood Materials, Inc. A critical part of recycling economics is the value of the recovered cobalt. Manufacturers working to remove cobalt from their products might produce the unintended consequence of reducing recycling. A novel approach is to maintain the cathode's crystalline structure, eliminating the significant energy expense of recreating it. While cathode materials are the focus of most recycling efforts due to their high economic value, recycling additional battery components could improve the overall sustainability of lithium-ion batteries. Studies have found that components such as the battery casing, current collectors,
electrolyte, and
separators have potential to be recycled given further research into processing methods. , several facilities are operating and under construction, including
Fredrikstad in Norway and a black mass facility in
Magdeburg, Germany in 2023. In early 2022, research published in Joule showed that recycling existing lithium-ion batteries by focusing on a method that refurbishes the cathode showed that this technique perform just as well as those with a cathode made from original materials. The study showed that the batteries using the recycled cathode charged faster and lasted longer than new batteries. By 2023, several companies had moved beyond research and had set up process lines to recycle commercial quantities of Li-ion batteries. In its Nevada pilot plant, the
Redwood Materials process had recovered more than 95% of important metals (including lithium, cobalt, nickel and copper) from of old
NiMH and Li-Ion packs. Recently, research from
Gunther Rupprechter laboratory published in Green Chemistry demonstrated that
Ni recovered from the cathode powder of spent
NiMH batteries can be upcycled into a catalyst (Ni/η-Al2O3), which enables the production of synthetic fuel (
methane) through
CO2 hydrogenation at a relatively low temperature of 250°C, reducing
e-waste while supporting clean energy and
CO2 utilization.
Battery composition by type Italics designates button cell types.
Bold designates secondary types.All figures are percentages; due to rounding they may not add up to exactly 100. ==Battery recycling by location==