Dealing with lithium-ion/EV battery fires: safety guidelines

May 29, 2024 EV battery, Lithium-ion batteries 11 min read

FIRETECH HCT has over three decades of combined experience developing firefighting solutions for critical and hazardous applications. Abhishek Bagwe (L) is the Director of FIRETECH HCT. Adish Bhamte (R) is an Engineer at FIRETECH HCT with around 5 years of experience designing firefighting solutions for industrial applications.

In this article for EVreporter, the authors discuss the best practices and safety guidelines for handling lithium-ion/EV battery fires, outlining both do’s and don’ts to ensure maximum safety for individuals and property.

Introduction

Lithium-ion Batteries (LIBs) are becoming extremely popular in energy storage applications, but a substantial fire risk is associated with their use. In recent years, concerns about battery safety have become increasingly significant with the proliferation of electric vehicles (EVs) and the widespread adoption of lithium-ion batteries in various applications. While lithium-ion batteries offer numerous advantages, incidents of battery fires have raised questions about the appropriate methods for dealing with such emergencies. Let’s dive right in to understand some of these methods.

Understanding Lithium-ion battery fires

Mechanical abuse (dropping, breaking, smashing, piercing), electrical abuse (overcharging, discharging) and thermal abuse (excessive heating) lead to internal short circuits in the battery cell. Once a single battery cell undergoes an internal short circuit, it produces a rapid heat and releases a large amount of gases (off-gases), causing a small explosion. This extreme heat and pressure buildup leads to a phenomenon called thermal runaway. Thermal runaway is a chain reaction process. During thermal runaway, the temperature of cells and modules increases abruptly and can result in an explosion. Lithium-ion battery fire is a complex phenomenon because it involves graphite anode (flammable solid material), organic electrolyte (flammable liquid), combustible gas (flammable gas) and small quantities of lithium metal (combustible metal).

Generally, the thermal runaway phenomenon is unavoidable after the first cell failure. Since LIB fire generates oxygen during combustion, it becomes even more complex to extinguish.

Effect of conventional firefighting media for LIB fire extinguishment

Several studies have been conducted to study the impact of conventional firefighting media on Lithium-ion Battery fires.

Carbon Dioxide (CO₂) is not an effective agent for LIB fire as burning of LIB will produce oxygen and cause reignition, reducing the smothering effect of CO₂.

Dry chemical powder is one of the most used firefighting media across the globe due to its application in multiple types of fire. However, it fails to extinguish the LIB fire.

Firefighting foam is used to fight hot-temperature liquid fuel fires. It blankets the fuel and flames, thus smothering the surface of the fuel. The presence of jet fires and high-velocity flammable gas venting during the thermal runaway stage in LIB disturbs the blanket created by the firefighting foam, thus not providing the smothering effect required for extinguishment.

Other firefighting media, such as chemical gases and inert gases, have also not shown consistent and significant fire extinguishment results.

As of now, the only conventional media that helps control LIB fire is water. The study on the extinguishment of LIB fire using water shows that a large amount of water is required to extinguish LIB fire, and it can still exhibit thermal runaway up to 72 hours after initial extinguishment. A thumb rule indicates that around 300 – 700L water is required to extinguish the fire in a 1kWh LIB.

Image Source: BatterySafety

What is the most effective solution for Li-ion battery fire?

Spherical Micelle technology-based Encapsulator Agents are the only media suggested by NFPA (National Fire Protection Association), the world’s leading fire protection body, for Li-ion battery fire. NFPA 18A Standard on Water Additives for Fire Control and Vapor Mitigation, in section A4.3, highlights the effectiveness of an encapsulator agent on Li-ion battery fire, including BESS.

In India, FIRETECH HCT has developed an encapsulator agent named F500EA, which has been deployed to suppress LIB fires in several applications. F500EA is UL listed agent and conforms to NFPA 18A. F500 EA is a multiclass firefighting agent. Various third-party testing organizations, including KIWA, DEKRA, Daimler, Bosch, Fraunhofer University, TU Clausthal, Bureau Veritas and IRClass, have extensively tested F500 EA for its effectiveness on Li-ion battery fires and have validated its performance for extinguishment as well as for prevention of re-ignition.

How does it work?

F500EA is an organic molecule with a polar head and a non-polar tail. When mixed with water, its polar head attaches itself to a water droplet with the non-polar tail sticking out. When applied to LIB fire, the non-polar tail rearranges itself to encapsulate the flammable electrolyte (fuel) present in the batteries, thus making it unavailable for the oxidation process and stopping the further propagation of the fire. F500EA also reduces the surface tension of water, and thus, water is able to penetrate the seat of the fire and absorb the heat of the fire. Since this phenomenon occurs at the molecular level, F500EA is able to break the chain reaction of free radicals and stop propagation. All these three effects together quickly knock down the fire, and encapsulation of fuel ensures there is no further re-ignition.

How to avoid Li-ion battery fires?

Thermal Management: Effective thermal management systems within battery packs can help regulate temperature and prevent overheating, reducing the risk of thermal runaway and fire. These systems can include thermal insulation, heat sinks, and active cooling systems.

Gas Release Mechanism: Incorporating mechanisms that allow for the safe release of gases generated during battery failure or overcharging can help mitigate pressure buildup within the battery enclosure, reducing the risk of explosion or fire.

Early Detection System: Advanced monitoring and detection systems can help identify potential battery issues, such as off-gas, overheating, or voltage irregularities before they escalate into a fire hazard. Early detection allows for prompt intervention and mitigation.

Emergency Response Protocol: Establishing clear protocols and procedures for responding to incidents is crucial for minimizing damage and ensuring the safety of personnel and property. This includes protocols for evacuations, fire suppression, and containment measures.

Regulatory Compliance: Adhering to relevant safety standards and regulations specific to lithium-ion batteries is essential for ensuring their safe use and handling. Compliance with standards such as UL (Underwriters Laboratories) and IEC (International Electrotechnical Commission) can help mitigate fire risks through rigorous testing and certification processes.

Do’s in case of an LIB fire

Safety first: The safety of individuals should always be the top priority. If a lithium-ion battery catches fire, evacuate the area immediately and ensure everyone maintains a safe distance from the fire to avoid exposure to toxic fumes and potential explosions.

Alert the authorities: Contact emergency services as soon as possible to report the fire and provide them with relevant information such as the location, type of battery, and any other pertinent details that can assist them in responding effectively to the situation.

Use suitable fire extinguishers: If it is safe to do so and you are trained in handling fires, use F500EA extinguishers specifically designed for LIB fires. Its Spherical Micelle technology encapsulates the fuel and vapours on a molecular level, making them non-flammable.

Control surrounding fires: If the battery fire spreads to surrounding materials or objects, use appropriate firefighting equipment to contain and extinguish these secondary fires while maintaining a safe distance from the battery.

Cool exposed batteries: If nearby batteries have not caught fire but are at risk due to heat exposure, use F500EA agents to dissipate heat and prevent further thermal runaway.

Follow manufacturer guidelines: If available, refer to the manufacturer’s guidelines or safety instructions for handling battery fires. These guidelines may provide specific recommendations tailored to the type of battery and associated risks.

Don’ts in case of an LIB fire

Do not approach unprotected fires: Do not attempt to extinguish a lithium-ion battery fire without appropriate protective gear and firefighting equipment. The intense heat and toxic fumes emitted during a battery fire pose significant health risks.

Do not ignore early warning signs: Take immediate action upon detecting signs of a potential battery fire, such as smoke, unusual odours, or thermal runaway indicators, such as rapid temperature rise. Ignoring these warning signs can lead to escalated emergencies.

Do not assume the fire will self-extinguish: While some battery fires may self-extinguish if the thermal runaway is contained within the battery, relying solely on this assumption is not advisable. Prompt intervention is necessary to minimize the risk of further escalation.

Do not attempt to disassemble batteries: Avoid attempting to disassemble or tamper with lithium-ion batteries, especially if they are damaged or compromised. Disrupting the battery casing can expose reactive materials to air and increase the likelihood of fire or explosion.

Do not reuse damaged batteries: Discard or recycle damaged lithium-ion batteries properly according to relevant regulations and industry standards. Attempting to reuse or repurpose damaged batteries can pose safety hazards and increase the risk of subsequent fires.

Concluding Remarks

Dealing with lithium-ion/EV battery fires requires a combination of preparedness, caution, and adherence to established safety protocols. By following the do’s and don’ts outlined in this article, individuals can effectively mitigate risks associated with battery fires and minimize potential harm to themselves and the surrounding environment. It is essential for stakeholders across industries, including manufacturers, emergency responders, and the general public, to remain vigilant and proactive in addressing battery safety concerns.