Last reviewed 2 October 2013
Caroline Hand discusses how to dispose of waste lithium batteries.
Lithium batteries come in a variety of shapes, sizes and chemistries. Besides the use of small lithium button cells used in watches, digital cameras and other consumer appliances, there are many specialised batteries for scientific, military, aerospace and commercial applications. There are two basic categories of lithium battery: non-rechargeable batteries containing lithium metal, and rechargeable batteries containing salts of lithium. Rechargeable lithium ion (li-ion) batteries are used in mobile phones and laptops, and larger versions power electric cars. Lithium polymer batteries are a category of li-ion rechargeable batteries, which have a range of laboratory and scientific applications, as well as being used in consumer electronics such as laptops and tablets.
Hazards of waste lithium batteries
Lithium metal heats up when exposed to water and can easily catch fire. Lithium-ion batteries were implicated in a plane crash in Dubai in 2010 and consignments of these batteries are now banned from UK and US aircraft, although individual passengers are still allowed to take their laptops on board.
Those responsible for workplace health and safety should be aware that batteries containing metallic lithium become hazardous when the outer casing is damaged and the contents exposed. If improperly disposed to landfill, the batteries can catch fire below the surface of the landfill; landfill fires can burn for a long period and are very difficult to extinguish. However, most consumer batteries still end up in landfill and this is not regarded as a serious risk to the environment. Lithium batteries should never be incinerated due to the risk of explosion.
Lithium batteries can provide extremely high currents and can discharge very rapidly when short-circuited. A too-rapid discharge of a lithium battery can result in overheating of the battery, rupture, and even explosion. Lithium-thionyl chloride batteries are particularly susceptible to this type of discharge. Consumer batteries are much safer, as they incorporate overcurrent or thermal protection or vents in order to prevent explosion.
Pros and cons of recycling
With the exception of lead acid vehicle batteries, battery recycling has not been an economic option in the past as it costs much more to recycle a battery than to dispose of it to landfill. Furthermore, although battery recycling conserves valuable metals, according to US statistics recycled lithium is five times more expensive than lithium obtained through mining and uses six times as much energy as the processing of virgin ore. Lithium-ion batteries only contain a very small percentage of lithium, which is not economic to recycle.
Strategic value of lithium
One of the key justifications for recycling waste electrical and electronic equipment is that it conserves valuable metals such as rare earths, which are either scarce or can only be found outside the EU — whether in China or in politically unstable regions. In the case of lithium batteries, there is not such a strong rationale for recycling.
Lithium is not included in the EU's list of critical raw materials because, compared with other metals, both the supply risk and economic importance are relatively low. However, it was classified as a strategically important metal by the UK Parliament's Science and Technology Committee on account of the projected growth in demand for vehicle batteries. In 2011, the University of Michigan carried out a study into the availability of lithium and concluded that global resources are adequate to meet the demand for electric vehicles throughout this century; looking further ahead, though, an EU study predicted that reserves could be exhausted by 2050 if there is high market penetration of electric vehicles. Over 40% of the world's lithium reserves lie in Bolivia and Chile, but Bolivia has not yet allowed overseas companies to mine the salt flats in which the deposits are found.
The Batteries Regulations 2009
It is important to know the impact of the Batteries Regulations 2009. The EU Batteries Directive, implemented in the UK by the Waste Batteries and Accumulators Regulations, introduced a producer responsibility regime for batteries by which manufacturers and importers of batteries pay for their collection and recycling. Retailers and other suppliers who sell more than 32kg of batteries each year must take them back from consumers free of charge, and battery collection bins are now seen in most stores. The UK as a whole was set a target of 25% collection of consumer batteries by 2012, rising to 45% by 2016. DEFRA's statistics indicate that the initial target has been met, with a provisional figure of 27.71% of batteries collected for recycling in 2012.
The actual recycling is organised by compliance schemes such as BatteryBack, which collects batteries on behalf of its members and ensures that they are recycled to the standards laid down in the directive. For lithium batteries, at least 50% of the collected batteries must be recycled (the targets are higher for lead-acid and Nickel Cadmium (NiCd) batteries).
This legislation has created a market for battery recycling and has resulted in the development of new infrastructure. Until recently, all collected batteries were sent to other European countries, such as Belgium, for recycling. However, UK capacity is now set to grow significantly. Europe's first facility for the recycling of lithium ion batteries was opened at Golspie, Scotland in 2004 by AEA Technology and, in October 2010, Veolia unveiled its plans to build a recycling facility for portable (consumer) batteries. This new capacity should reduce the cost of recycling relative to disposal.
Recycling of lithium batteries
Lithium battery recycling is well established in the USA and an American company gives the following description of their recycling process:
“Lithium ion batteries are recycled in a specialised 'room temperature, oxygen-free', mechanical process during which the battery components are separated into three end products. These items are cobalt and lithium salt concentrate, stainless steel and copper, aluminium and plastic. All of these materials are then put back on the market to be reused in new products.”
To recycle batteries containing lithium metal, ferrous and non-ferrous metals are recovered using an alkaline solution, and the lithium is converted to lithium carbonate, which can be used again in batteries.
Another US company uses liquid nitrogen to freeze lithium-based batteries before shredding, crushing and removal of the lithium, as well as other battery components. The lithium is dissolved in a solution to make the metal non-reactive and is sold for producing lubricating greases. Similarly, the cobalt is separated, collected and sold.
Practical guidance on management of waste lithium batteries
Ideally, all waste batteries should be collected separately and sent for recycling. Free collection services are offered by the battery compliance schemes and waste contractors. With lithium batteries, care must be taken to ensure that the batteries are not damaged while awaiting collection. On no account should these batteries be incinerated.
Special precautions and procedures are necessary for lithium polymer batteries. Undamaged batteries should be discharged and stored safely in salt water; the detailed procedure is given below.
Place the Lithium Polymer battery in a fireproof container or bucket of sand.
Connect the battery to a Lithium Polymer discharger and discharge safely until its voltage reaches 1.0V per cell or lower. For resistive load type discharges, discharge the battery for up to 24 hours.
Prepare a bucket or tub containing three to five gallons of cold water, and mix in 1/2 cup of salt per gallon of water. This container should have a lid, but it does not need to be airtight.
Drop the battery into the salt water. Allow the battery to remain in the tub of salt water for at least two weeks.
Remove the Lithium Polymer battery from the salt water and dispose of as hazardous waste.
Damaged batteries should be placed directly into salt water and disposed of as hazardous waste.
Hazardous waste classification and transport
Workplace management may be somewhat surprised to know that lithium batteries are not classified as hazardous waste by the Hazardous Waste Regulations 2005. The European Waste Catalogue lists NiCd and mercury-containing batteries as hazardous, but there is no specific category for lithium batteries, merely a category of “other batteries” classified as non-hazardous.
Lithium is, however, mentioned in the Environment Agency's guidance on hazardous waste as a substance whose presence could render a waste hazardous on account of its flammability.
Waste management companies are likely to err on the side of caution where batteries are concerned: for example Wastecare, which is a partner in the Batteryback scheme, consigns all batteries as hazardous waste. Where lithium batteries are mixed with other types of battery the consignment should be classified as hazardous waste.
The Environment Agency, in its guidance on battery returns, explains that although non-hazardous in terms of the 2005 Regulations, lithium batteries still present a risk. It should be realised that they should not be put in the post (and are banned from air mail) and are subject to dangerous goods legislation when transported by road, rail or sea. Lithium batteries are classified by the ADR Regulations as Class 9 (other dangerous goods) and must be packaged in a UN container conforming to Packing Group II specifications.