Caroline Hand discusses the options for dealing with waste lithium batteries, and advises on their safe and legal handling and disposal.
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.
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. Currently, there are an estimated 80 different li-ion battery chemistries in production.
Lithium polymer batteries are a category of li-ion rechargeable batteries. They have a range of laboratory and scientific applications, as well as being used in consumer electronics such as laptops and tablets. These batteries need to be disposed of with particular care (see below).
Hazards of waste lithium batteries
Lithium metal heats up when exposed to water and can easily catch fire. Li-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. Passengers may take spare batteries in their carry-on luggage if precautions are taken to prevent short circuits.
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 was not an economic option in the past. The introduction of the Batteries Directive created an incentive to recycle the majority of consumer batteries, and has resulted in the development of battery recycling infrastructure in Europe, but while nickel-cadmium (NiCd) and other chemistries are being successfully recycled, it is still not economic to recycle lithium batteries. In consequence, a mere 5% of lithium batteries are currently recycled in the EU.
Li-ion batteries only contain 3% of lithium, and 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.
Speaking at the International Battery Recycling Congress in 2016, the Secretary-General of the European Battery Recycling Association (EBRA), said at the present point in time conditions for a closed loop system have not yet been met. However, the technology to recycle these batteries does exist (see below) and there are a small number of recycling plants worldwide. Europe’s first facility for the recycling of li-ion batteries was opened at Golspie, Scotland in 2004 by AEA Technology.
Strategic value of lithium
One of the key justifications for recycling waste electrical and electronic equipment (WEEE) is that it conserves valuable metals such as rare earth, 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. Recent estimates indicate that there is more than enough lithium in the world’s reserves to last until 2050 and beyond, even with the projected growth in electric vehicles.
The problem of electric vehicle batteries
By 2040, there will be no more diesel and petrol powered vehicles on sale in the UK and France. As “greener” electric vehicles take over from the traditional models, industry is having to work out what to do with the lithium batteries once they reach the end of life. Recent predictions indicate that there could be 11 million tonnes of spent li-ion batteries in need of recycling between now and 2030. The large size of the batteries makes it impracticable for the car owners to store or dispose of them, but the recycling of lithium from car batteries is just as uneconomic as the recycling of small lithium cells, for the reasons given above.
However, because vehicle batteries also contain valuable cobalt, there is an incentive for the battery industry to develop recycling technology. The Belgian recycling company Umicore has developed a process to recycle batteries for Tesla and Toyota: this reclaims cobalt and other metals, but unfortunately, the lithium itself is left as a byproduct rather than a saleable material.
Another solution, which is perhaps more practicable, is to use the spent vehicle batteries as electricity storage units either for homes or for the grid. Waste car batteries still have 70% of their capacity and are suitable for storing electricity generated by solar panels or wind turbines. Nissan is currently pursuing this route, in partnership with specialist power storage companies.
Significance 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. Available statistics indicate that the 2016 target has not been met.
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 NiCd batteries); the point to note is that most lithium batteries are not actually collected for recycling and go straight to landfill.
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 USA 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.
The Canadian recycling start-up Li-Cycle claims it can recycle all types of li-ion batteries, recovering up to 90% of materials including lithium, cobalt, copper, and graphite. They are optimistic that this process will be economic because it recovers the more valuable and scarce cobalt alongside lithium.
Practical guidance on management of waste lithium batteries
Ideally, all waste batteries should be collected separately. 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.
Safety precautions for lithium polymer batteries
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 (WM3) 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. They should not be put in the post (and are banned from airmail) 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.