Battery Recycling : The Hidden Danger: Li-ion Batteries as Fire Hazards in Waste Management Facilities

In an age dominated by portable electronics and electric vehicles, lithium-ion (Li-ion) batteries have become ubiquitous. These powerhouses of energy storage have revolutionised our daily lives, offering efficient, rechargeable energy solutions. However, their widespread use comes with a hidden danger, especially when improperly disposed of in waste management facilities.

When damaged, overcharged, or exposed to extreme temperatures, Li-ion batteries can undergo thermal runaway—a chain reaction where the battery overheats, leading to the release of flammable electrolytes and potentially causing a fire or explosion. In the controlled environment of a device, safety mechanisms help mitigate these risks. However, once discarded and mixed with other waste materials in landfills or recycling facilities, these safety measures are often compromised. The fire departments in New York and San Francisco alone report over 669 such incidents combined since 2019.

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The main problem here is obviously the incorrect dispose of the batteries. Waste management facilities are generally not equipped to handle the unique hazards posed by Li-ion batteries. When batteries are improperly discarded and end up in waste streams, they can come into contact with other metallic objects, causing short circuits and sparking fires. The volatile nature of Li-ion battery fires makes them difficult to extinguish and can lead to catastrophic consequences, including property damage, environmental pollution, and even injury or loss of life.

Moreover, the recycling process for electronic waste (e-waste) presents its own set of challenges. Li-ion batteries are often not properly segregated from other materials during recycling, increasing the risk of thermal events. The mechanical shredding and sorting procedures used in recycling facilities can further exacerbate these dangers by puncturing batteries and triggering thermal runaway.

The most effective form of risk mitigation is eliminating the hazard, as Gregory Maines, Lead Engineer at Jensen Hughes, an expert in safety, security and risk-based engineering and consulting, says: "Consumers must be provided with a convenient alternative for their e-waste disposal and be aware that this alternative exists in order to change their behaviour. E-waste disposal programs which incur charges to the consumer at the point of disposal or require transportation to a depot are a disincentive to proper disposal, which is being recognised in the development of extended producer responsibility (EPR) programs that require producers to consider the costs of disposal and share some of these costs in their up-front pricing."
More and more countries implement EPR policies giving manufacturers a financial incentive to make their products easier and safer to dispose of at the end of their lifecycle and to work proactively with the waste management industry to achieve these goals. EPR regulations for Li-ion batteries have been adopted in New York and California and are being developed by the European Union for implementation in 2025. "In the long term, these regulations should reduce improper disposal of lithium-ion batteries to ensure that processing and recycling occur at facilities designed for this hazard," says Gregory Maines.

But as long as not all batteries end up in the correct waste management plant, especially material recovery facilities (MRF) have to deal with improperly discarded Li-ion batteries. "Material recovery facilities appear to be the most heavily affected, in part due to a widespread mistaken belief among consumers that lithium-ion batteries are recyclable as part of typical household collection programs and the additional processing steps that occur at these facilities,", explains Greogry Maines.
Contrary to "conventional" fires at waste management plants - plastics or cellulosic, can be difficult to ignite and may encounter a prolonged period of smouldering prior to the outbreak of a flaming fire - the intensity of lithium-ion battery fires can accelerate the ignition of other materials, giving facility operators less time to respond before a fire grows beyond their ability to control.

Therefore employees must be provided with training to identify hazardous materials of all kinds and appropriately respond to observations of these materials during all stages of the waste management cycle, Mr Maines explains: "Fire growth potential is dictated by several factors, but the primary considerations are the heat of combustion and exposure to oxygen in the air. The heat of combustion is the net amount of energy released by a fuel source; this is generally highest for plastics and cellulosic and can be reduced with increasing moisture content. Management of pile size, composition, and moisture content must consider the potential for fires, particularly at intake facilities and when processing waste streams into segregated piles of materials with high fire growth potential. In this context, lithium-ion batteries should be considered as an ignition source, while the fire growth potential of the surrounding waste pile is what defines the upper-limit consequence of ignition."

Remaining vigilant and segregating materials is a labour-intensive process. "One interesting area of development is the integration of machine learning algorithms (often termed "AI") to identify and reject hazardous materials from waste streams," Gregory Maines says. "While these solutions are not yet in widespread use, they may one day allow a much smaller team of facility operators to supervise the robots in doing the tedious work of watching the waste stream and separating high-risk materials for special processing."

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For facilities that are not intended to handle Li-ion batteries, passive fire management practices along with active systems designed to mitigate fire growth in surrounding combustible materials are generally sufficient. But of course, not only MRFs have to be aware of the fire hazard. Facilities that are intended to handle Li-ion batteries and other potentially hazardous wastes, specialised protection systems play an important role in the overall protection scheme. "Automatic detection devices including heat, smoke, spark, or flame detectors can be used to notify facility operators of incipient fire events or shut down equipment to prevent the spread of burning materials through a facility prior to emergency response actions. These detection devices can also be used as the initiating devices for integrated fire protection systems to suppress fire growth," Gregory Maines says.

In conclusion, addressing the fire hazard posed by Li-ion batteries in waste management facilities requires a multi-faceted approach. Public awareness campaigns are essential to educate consumers about the proper disposal methods for batteries and the importance of recycling e-waste responsibly. Enhanced collection systems, such as designated drop-off locations for hazardous materials, can help prevent batteries from entering the waste stream. Additionally, investment in advanced sorting and recycling technologies that can safely handle Li-ion batteries is crucial for mitigating risks within recycling facilities.

Furthermore, industry standards and regulations must be updated to reflect the growing prevalence of Li-ion batteries in consumer products and the unique hazards they pose. Manufacturers should be incentivised to design products with easier battery removal and recycling in mind, reducing the likelihood of batteries being improperly disposed of in the first place.