How We Recycle Batteries

Lithium batteries come in several forms, but in everyday life you mainly encounter two types: Lithium-ion, which are rechargeable, and primary lithium, which are not. Lithium-ion batteries are found in modern laptops, phones, game consoles, and electric vehicles. They are both powerful and more environmentally friendly than earlier options, such as cadmium batteries. Up to 90 percent of them can be recycled. Primary lithium batteries are smaller and less common, found in items such as watches and toys, and are difficult to recycle – which is why we instead recover energy from them.

Contents of a lithium-ion battery:

Aluminium – 15–25%
Copper – 5–15%
Lithium – 1–10%
Cobalt – 1–15%
Nickel – 1–15%
Iron – 1–20%
Paper and plastic – 6–15%

Cadmium batteries, also known as nickel-cadmium batteries, contain the hazardous heavy metal cadmium. They sometimes appear in older electronics, especially tools – but are generally rare in today’s collection due to bans that have been gradually implemented in Sweden and the EU since the early 2000s. Some exceptions to the ban have existed in legislation. Today, the only remaining exceptions apply to certain industrial products where no good alternatives are available, such as emergency lighting, alarm systems, and certain medical devices.

Contents of a nickel-cadmium battery:

Iron – 40%
Nickel – 22%
Cadmium – 15%
Paper and plastic – 23%

When cadmium batteries were phased out, they were replaced by nickel-metal hydride batteries. These are often cylindrical and can look like ordinary alkaline batteries, but they are rechargeable. Nickel-metal hydride batteries contain no heavy metals but should still be returned for recycling when they can no longer be charged. They can be recycled to up to 90 percent.

Contents of a nickel-metal hydride battery:

Nickel – 33%
Iron – 30%
Lanthanides – 10%
Cobalt – 3%
Manganese – 1%
Zinc – 1%

Lead batteries are large, heavy batteries commonly found in cars, mopeds, and garden equipment. Large batteries like these are returned directly to a recycling centre – or to a store or petrol station when you purchase a new one. At the recycling facility, the batteries are drained of sulphuric acid, which can be neutralised into water using sodium hydroxide. The lead cell is fed into a blast furnace. In this pyrometallurgical process, lead, matte, and slag are extracted. The lead is alloyed and sold, while the slag and matte are deposited in Boliden-Bergsöe’s own landfill site. The legally required recycling rate for lead batteries is 65 percent, but the actual rate is often higher.

The battery can account for up to 30 percent of the total weight of an electric passenger car. It’s not uncommon for a standard EV battery to weigh between 300 and 600 kg. In electric trucks, forklifts, and machinery, the battery weight can vary even more. EV batteries are handled in a specific way during the recycling process and are transported only by specially trained carriers. The battery is discharged, and if possible, any remaining electricity is used locally. The battery is then manually dismantled. The different components are sorted and processed in several steps to recover as much material as possible. Any material that cannot be reused is recycled or otherwise managed according to environmental requirements.

Batteries containing the heavy metal mercury are mainly found in certain button cell batteries. These are small and round and can be used in anything from watches to singing birthday candles and remote controls. Mercury is an element that cannot be broken down and instead accumulates in soil, water, and living organisms. It is hazardous to both the environment and human health. Since October 2015, it has been prohibited in Sweden to sell batteries and products with built-in batteries containing more than 0.0005% mercury by weight.

El-Kretsen collects these batteries partly via the country’s battery collection boxes and partly by manually removing them from collected products. Different battery types are sorted according to their chemical content so that they can be recycled – or in the case of mercury, managed for phase-out from the lifecycle. Button cell batteries are sorted using a shaking table, which separates out those below a certain size into their own fraction. As a precaution, all small button cells are handled in the same process, even though only some contain mercury.

To give an idea of how common mercury is among ordinary batteries: of 2,000 kg of mixed batteries received at El-Kretsen’s sorting facilities, approximately 1 kg contain mercury. The amount of metallic mercury in this kilo is just a few percent. In total, around 3,500 tonnes of batteries are handled each year, with barely two tonnes containing mercury.

For waste containing mercury above a certain threshold, laws govern how it must be permanently stored. In Sweden, deep geological storage is required, but such a facility does not yet exist in the country. Since 2014, all mercury-containing batteries collected by El-Kretsen are sent to Fortum Waste Solutions in Kumla, where they are stored pending mercury stabilisation and eventual final disposal. Former salt mines in Germany are among the facilities used for final storage.