AVD: Advanced Fire Protection for Lithium Batteries

From the battery in your home to the world's largest energy-storage systems

Lithium-ion batteries have transformed the way we live, work and move.

They power phones, laptops, power tools, e-bikes and mobility devices. They are increasingly used in commercial energy storage, electric vehicles, marine propulsion, rail transportation and large-scale Battery Energy Storage Systems (BESS).

But as batteries become larger and more energy-dense, the consequences of a battery fire become increasingly serious.

A lithium battery fire is fundamentally different from an ordinary combustible-material fire. When a battery enters thermal runaway, cells can generate intense heat, release flammable gases and potentially propagate the failure from one cell to another.

The challenge is therefore not simply to extinguish the visible flame.

The challenge is to control the battery, manage the heat and prevent propagation.

This is where Aqueous Vermiculite Dispersion (AVD) provides a powerful additional layer of protection.

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What is AVD?

Aqueous Vermiculite Dispersion (AVD) is a water-based mineral fire-suppression agent formulated with finely processed vermiculite.

When applied to a burning or overheating lithium battery, AVD provides two important functions.

First, the water component absorbs heat from the battery and surrounding materials.

Second, as the water evaporates, the mineral component remains on the heated surface, forming a protective layer that helps reduce heat transfer and isolate the affected area.

AVD therefore does more than attack the visible flame.

Its purpose is to help cool, contain and control the thermal event at the battery itself.

That distinction is critical when dealing with lithium-ion batteries.

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Lithium battery fires are not ordinary fires

With a conventional fire, extinguishing the flame can often mean that the fire has been controlled.

A lithium battery can be very different.

A battery may continue to generate dangerous heat after the visible flames have been suppressed. A cell undergoing thermal runaway can transfer heat to neighbouring cells, potentially causing further failures and propagation through the battery pack.

This creates a sequence of challenges:

Thermal runaway → heat generation → cell propagation → fire → re-ignition

Effective lithium battery fire response therefore needs to address more than the flames.

It needs to address the thermal event itself.

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The LithMag two-fire approach

LithMag's approach recognises that a lithium battery incident can involve two interconnected fires.

Fire 1 — The peripheral fire

The first is the fire surrounding the battery.

This may involve plastics, wiring, vehicle interiors, equipment, furnishings, fuels or other combustible materials.

A suitable firefighting foam such as Trident PFAS-free foam can be used to rapidly attack this external fire.

Fire 2 — The battery core

The second is the battery itself.

Even when the surrounding flames have been controlled, the battery may remain extremely hot and capable of continuing to propagate.

This is where AVD is designed to play its role.

AVD is applied directly to the affected battery to provide cooling and thermal protection while helping isolate the battery from its surroundings.

Extinguishing the flame is not necessarily the same as controlling the battery.

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Protection that scales with the battery

One of the advantages of AVD technology is that the underlying firefighting principle can be applied across a remarkably wide range of battery systems.

The risk changes as battery capacity, energy density and installation complexity increase.

Home and personal equipment

Lithium batteries are now found throughout the modern home.

Examples include:

• E-bikes

• E-scooters

• Power tools

• Laptops

• Portable power stations

• Mobility equipment

• Consumer electronics

For smaller battery systems, the priority is rapid intervention before a developing battery fire can spread to the surrounding home or workplace.

Portable AVD extinguishers provide a targeted means of attacking the battery itself.

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Commercial and workplace batteries

The same risk exists in offices, workshops, warehouses, construction sites, retail environments and industrial facilities.

Here the number and size of batteries can increase significantly.

A workplace may contain charging stations, power-tool batteries, mobility equipment, battery storage cabinets or other energy-storage systems.

Fire protection therefore needs to move beyond simply placing an extinguisher on the wall.

Where are the batteries?
How much energy is stored?
What happens if one enters thermal runaway?
Can personnel safely intervene?
What happens after the visible fire has been extinguished?

These questions form the basis of an effective lithium battery risk assessment.

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Electric vehicles and mobile energy systems

As battery systems become larger, the consequences of thermal runaway become correspondingly greater.

Electric vehicles, commercial vehicles, mobile equipment and other battery-powered platforms can contain substantial amounts of stored energy within tightly integrated battery packs.

Access can also be difficult.

A battery may be located beneath a vehicle, within a protected enclosure or inside a structure that makes direct firefighting challenging.

The objective is therefore not simply to attack the visible fire.

It is to control the thermal event and prevent propagation wherever practical.

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Marine and electric vessel applications

The next generation of marine transportation is bringing increasingly large lithium battery systems onto vessels.

Electric boats, hybrid propulsion systems, ferries, workboats and other vessels can carry substantial battery capacity in confined machinery spaces or dedicated battery compartments.

At sea, the consequences of a battery incident can be particularly serious.

Access may be restricted, evacuation options limited and external emergency assistance unavailable.

Battery fire protection therefore needs to be considered as part of the vessel's overall fire strategy.

AVD provides a means of directly attacking the battery thermal event while complementing conventional firefighting systems used to control surrounding fires.

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Rail and next-generation transportation

Rail transportation is also moving toward larger-scale electrification and battery energy storage.

Battery-powered and hybrid rail systems introduce many of the same challenges encountered in electric vehicles and marine applications, but often at a much larger scale.

Battery installations can be distributed across trains, contained within equipment compartments or integrated into propulsion systems.

For emergency responders, this creates a new requirement:

Understand where the battery is, understand how it can fail and have the equipment and procedures necessary to control the incident.

AVD forms part of the emerging toolkit for responding to these increasingly sophisticated battery systems.

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Battery Energy Storage Systems — BESS

At the largest end of the scale are Battery Energy Storage Systems.

BESS installations can contain enormous quantities of stored electrical energy distributed across hundreds or thousands of battery modules.

A thermal runaway event can potentially propagate from one cell to neighbouring cells and ultimately affect an entire module, rack or installation.

At this scale, firefighting is no longer simply an extinguisher problem.

It becomes an engineered risk-management problem.

Detection, isolation, ventilation, suppression, cooling, responder safety, contaminated firewater, site access and post-fire monitoring all become important considerations.

AVD can form one component of a comprehensive BESS fire-response strategy, particularly where direct cooling and thermal management of affected battery systems are required.

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One technology. Different scales of risk.

The battery may change.

The environment may change.

The scale may change.

But the fundamental challenge remains the same:

Control the heat. Control the battery. Prevent propagation.

From a single e-bike battery in a garage to a large-scale BESS installation, AVD provides a mineral-based approach to lithium battery fire suppression and thermal management.

The equipment and deployment strategy should always be matched to the battery, the environment and the potential consequences of failure.

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AVD is part of a complete fire strategy

AVD is not intended to replace every other firefighting system.

Lithium battery fire protection requires a layered approach that can include:

• Detection and early warning

• Battery isolation

• Ventilation and gas management

• Appropriate extinguishing agents

• Thermal monitoring

• Firefighter PPE

• Emergency procedures

• Containment

• Post-fire monitoring

• Safe recovery and disposal

The right question is therefore not:

“Which extinguisher should I buy?”

The better question is:

“What happens if this battery goes into thermal runaway — and are we prepared to control the entire event?”

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From risk assessment to response

LithMag works across the full spectrum of lithium battery fire risk.

From homes and small workplaces to industrial facilities, transportation, marine applications and large-scale energy storage, we help organisations understand their battery risks and develop appropriate response strategies.

Our approach combines risk assessment, equipment, training and practical response planning.

Because the best time to develop a lithium battery fire strategy is before the battery is burning.

Prepare for the battery you have today — and the battery systems of tomorrow.

LithMag
Lithium Battery Fire Safety

lithmag.ca