Batteries contain a range of metals which can be reused as a secondary raw material. There are well-established methods for the recycling of most batteries containing lead, nickel-cadmium, nickel hydride and mercury. For some, such as newer nickel-hydride and lithium systems, recycling is still in the early stages.

There are a number of different recycling processes for batteries, which are aimed at recovering a variety of materials:

• Lead can be recovered by either separating the different materials that make up the battery (lead, plastics, acid, etc.) prior to metallurgical processing. Alternatively, batteries can be processed as a whole through heat treatment in a particular type of furnace with metals being recovered at the end of his process.
• NiCd batteries can be reprocessed through a similar thermal technique, which recovers cadmium and iron-nickel for steel production.
• Batteries containing mercury (button cells) are most commonly processed using a vacuum-thermal treatment, in which the mercury vaporises. It condenses and eventually solidifies when temperatures are reduced and can then be reintroduced into the material cycle.
• NiMH batteries are reprocessed by mechanically separating the individual materials (plastic, hydrogen and nickel) within a vacuum chamber to prevent the escape of hydrogen. The output of this process is a product with high nickel content which can be used in the manufacture of stainless steel.
• Li-Ion batteries are currently reprocessed through pyrolysis (heat treatment) with the primary recoverable being the metal content.
• Zinc-carbon/air and alkaline-manganese batteries can be reprocessed using a number of different methods, which include smelting and other thermal-metallurgical processes to recover the metal content (particularly zinc).