The burning question – do we have a Li-Ion problem?

Author : Pablo Martinez-Moore, North Ridge Pumps

17 November 2022

There are now over 600,000 Electric cars registered in the UK. Sales have surged in recent years and with Petrol/Diesel Driven Cars expected to be banned from 2030, it is unsurprising to see Reuters reported this month that over 43% of sales for new cars in the EU during the last quarter were Hybrid and Electric.

Car being extinguished – Image: Brandweer Midden-en West-Brabant (Facebook)

Increased Lithium-Ion usage has not just been confined to cars, its popularity as a powering medium has surged in recent years, with it now being used in a variety of everyday appliances from power tools, lawnmowers, and scooters to Ebikes, forklift trucks and increasingly energy storage projects where renewably generated electricity is stored.

One unintended consequence of their surge in use has been the occurrence of EV or Lithium-Ion Fires, which often gives rise to the burning question - how to extinguish and contain such fires?

Causes of Lithium-ion fires:

Lithium-Ion fires usually start due to 5 reasons:

1. Battery is damaged

2. Short Circuit

3. High or Low Temperatures

4. Overcharging

5. Manufacturing Defect

Once a battery becomes damaged thermal runaway can occur. Thermal Runaway is caused during battery overheating, where the internal energy of the battery rapidly dissipates causing a release of Hydrogen Cyanide and carbon Monoxide gasses, melting of the surrounding structures, ignition of adjacent battery cells with the possibility of explosion.

How to extinguish & contain a lithium Ion Fire

Traditional extinguishers containing either water, powder and CO² are not designed for lithium fires. They may be suitable for small EV fires, but due to the energy present in larger battery packs, complexity of access which is usually deep within a car chassis and number of Li-Ion cells which can reach over 7000 cells per EV vehicle, a different approach is required.

A typical Petrol or diesel vehicle fire requires around 1500 litres of water to extinguish, however an EV battery fire requires in the region of 2000- 90,000 litres of water for a single EV car fire to be extinguished.

Some fire brigades have been known to place cars into water filled shipping containers or can as a method of fire suppression due to the reignition of batteries or continuous dousing of battery fires being time consuming.

Easy to maintain high pressure peristaltic pump

Water penetration to cool affected battery cells to prevent thermal runaway is not only difficult due to the tight and robust construction of battery packs which are difficult to access, but it is also possible for water to fuel fires as it reacts with lithium producing hydrogen gas which is highly flammable and explosive.

Furthermore as up to 90,000 litres of water can be used to cool fires, generating a slurry of chemicals containing liquids such as lithium hydroxide - a highly toxic yet clear, innocent looking liquid. These high alkaline, corrosive and toxic chemicals will flow into storm drains before spreading into rivers, streams, lakes or the sea as there is no effective way of stemming their flow when such quantities are produced.

When you consider that 90,000L of waste can be produced by a single vehicle, great consideration should be given to EV fire suppression technology, and how the lack thereof can halt your process, destroy assets, disrupt your supply chain and impact the environment.

Pumps for Lithium-Ion & EV Fire Suppression

So what technologies should be used to suppress lithium-ion fires and with what media?

There are a number of engineered liquids currently available for the suppression of such fires – liquids such as Aqueous Solutions or Aqueous Vermiculite Dispersion (AVD) fluids consisting of approximately 80% water and Vermiculite – a naturally occurring substance which creates a film over a batteries fire (similar to how platelets form in blood after a cut), preventing reignition and thermal runaway. Such aqueous solutions are chemically inert, non toxic and are applied in much lower volumes than that of water quickly extinguishing fires.

The fluids are applied as a mist via a jet or by sprinklers to deeply penetrate confined spaces, and battery pack structures. Due to their viscous nature, handling Aqueous Vermiculite requires a positive displacement pump such as a Peristaltic Pump which can produce high pressures and low flows producing the pressurised spray as required as in this case study.

A peristaltic is preferred as it operates without a mechanical seal, requires very little maintenance when stood for long periods without use, they can operate without fluid (run dry), are easily reversible and contain only one working part which requires very little maintenance. When maintenance is required it can be performed by one person without special tools or equipment making it the ideal pump for this application.

If you haven’t already, now is the time to review any existing Lithium Ion Fire Suppression System which relies solely on water, or powder extinguishers. With over 200 Ebike battery fires in New York alone this year, waste battery fires costing businesses over £150M in 2021 and increasingly reported safety concerns involving the shipping of vehicles, it is only a matter of time before such incidents experience their own thermal runaway.

If you are looking to implement a Lithium Ion Fire Suppression System, are finding traditional fire suppression technologies are not suitable and want to understand which pump technology may be most suited for your process, speak to us on 01773 302 660 or visit www.northridgepumps.com to see how we can help.

This article has been written by Pablo Martinez-Moore of North Ridge Pumps who has been involved in the pump industry for over 12 years and become a specialist in a range of pumping applications. Quite often Pablo works with customers from concept design, right through to project installation then completion or with customers who aren’t quite achieving the results expected or want a review of their aging process equipment.