The serious problem with Lithium-ion batteries

It seems like hardly a fortnight goes by when a fire at a recycling plant involving lithium-ion batteries isn’t in the headlines. We’ve had the devastating fire at the Abilities Group operation in April, and in May Simsmetal Industries was fined $30,000 for a fire at its scrap-metal yard in Favona in July 2023.

What exactly are lithium-ion batteries, why are they such a fire hazard, and what are we doing about them?

Lithium-ion batteries became commercially available in the 1990s and are now widely used to power a range of portable electronic devices, from e-cigarettes, hearing aids and cameras to laptops, e-bikes, electric vehicles, and sub-grid energy storage systems. It is likely an increasing number of electronic devices will continue to adopt this technology because of their superior battery properties compared with other forms of batteries, such as lead-acid or nickel-metal batteries.

It’s also more than apparent that New Zealand needs to take urgent action to standardise protocols for the disposal of lithium-ion batteries; without more regulation we’re going to have more fires caused by them.

There are two main reasons. First, lithium-ion batteries contain highly flammable components, which means that overheating, physical abuse, or short-circuiting can make them catch fire. Second, improper recycling practices often damage the protective casing of lithium-ion batteries, which also creates conditions that make them catch fire.

These batteries must be properly disposed of at designated collection facilities.

Additionally, those lithium-ion batteries built into electronic devices are not safe for untrained consumers or individuals to remove, and should be handled by a professional and certified lithium-ion battery recycling team.

Lithium-ion rechargeable batteries consist of six main components: a graphite anode, lithium compounds (containing nickel, manganese, iron, cobalt, etc) as cathode materials, an electrolyte, a separator, current collectors, and a protective casing.

Most electrolyte in lithium-ion batteries is a solution of lithium salts, dissolved in an organic solvent, which is extremely sensitive to moisture and oxygen in the air. This is why they are wrapped in protective steel or aluminium casing.

However, when that casing is compromised, the batteries can release toxic, flammable, and explosive gases, such as carbon dioxide, carbon monoxide, hydrogen, hydrocarbons, and hydrogen fluoride. The mixture of these gases creates conditions ripe for intense, self-sustaining and explosive fires.

Large batteries, such as those used in electric vehicles, are equipped with a battery management system, which ensure the batteries operate within safe limits. However, they are still inherently hazardous because of their use of highly reactive lithium metal (in non-rechargeable lithium batteries) and organic-based electrolytes.

There have been great efforts made to design and develop safer lithium-ion batteries, such as all-solid-state batteries. In these batteries, thin ceramic-based or polymer-based solid materials are used instead of the highly flammable and sensitive organic electrolyte used in conventional lithium-ion batteries. These emerging technologies have shown promising performance in the lab but there is a long way to go before they can be commercialised and adopted for industrial use.

If we really want to prevent fires caused by lithium-ion batteries in the recycling process, they should be identified and fully discharged before being carefully placed in designated collection facilities, and waste collection and processing workers should receive proper training on how to safely handle discarded batteries.

We also need to establish more battery collection facilities that are easily accessible and regularly monitored. Lithium-ion battery fires differ significantly from regular fires in terms of causes, behaviour, hazards, and suppression methods.

Lithium-ion battery fires are chemical-based and self-oxidising. They can go from smoke to full ignition extremely quickly (often in less than 10 seconds), and are difficult to control. They also release highly toxic gases during combustion. Therefore, each recycling or waste plant should have a professional team to manage the disposal and recycling of these batteries, and which should work closely with fire management services, battery recycling facilities, and battery manufacturers – especially those dealing with large-scale batteries.

Traditional fire extinguishers, such as water, foam, or dry chemicals, are ineffective at extinguishing lithium-ion battery fires, so those working with such batteries need a particular type of fire extinguisher, and workers must be able to access them within seconds.

Some local councils websites have listed locations to dispose of used batteries on their website, including Auckland Council. Several companies also offer information on how to safely dispose of batteries, such as Cell Supply NZ, Phoenix Recycling and wasteMINZ.

But these locations are more suitable for conventional batteries, such as AA-size alkaline batteries or coin-cell batteries, but not for modern electronic devices with integrated lithium-ion batteries.

Because of the superior battery properties of lithium-ion batteries, they have been increasingly used in portable electronic devices, and we should prioritise proper disposal and recycling protocols for these technologies, if we don’t want more fires caused by them. (It is not safe to remove pouch-cell lithium-ion batteries from smartphones, whereas in older Nokia or Samsung mobile phones, we could remove the lithium-ion batteries easily and safely.)

The rapid adoption and widespread use of lithium-based batteries across a broad range of electronic devices pose increasing challenges for disposal and contribute to the growing risk of lithium-ion battery fires.

In the short term, councils and local communities need to invest more in lithium-ion battery disposal facilities and public education.

In the long term, battery manufacturers – as well as companies that produce electronic devices with integrated lithium-ion batteries – should take greater responsibility for the proper disposal and recycling of these batteries. Manufacturers should adopt a closed-loop system that includes battery manufacturing, regular operation guidelines, and disposal protocols. All batteries would be labelled with a barcode, which could be scanned to access essential information such as disposal instructions and designated drop-off locations.

In a few decades, we have developed the technologies to deploy lithium-ion batteries in a myriad way, and we also have the capacity to develop the technologies to get rid of them.