Frank Brubakken, CEO and Product Designer at Bridgehill, highlights the development of fire blankets capable of withstanding extreme battery fire conditions
The inception of Bridgehill was primarily motivated by a desire to address fire safety in buildings.
My journey started following a small city fire in Norway, which led me to consider the possibility of creating materials that could prevent fires from spreading from one building to another.
This curiosity was the catalyst for an intensive research period where I dedicated over 2,000 hours, spanning more than a year, to learn about every type of textile available on the market.
However, around the same time, there was a significant amount of media coverage on the challenges associated with electric car fires.
This prompted me to delve into all the scientific research I could find, dating back to the 1970s, on lithium batteries—focusing on why they are particularly difficult to manage in fire situations.
I began to explore whether the solutions we were considering for buildings could also be adapted or improved for use with cars.
In 2015, there was a highly publicised incident involving a Tesla car that caught fire, which garnered attention worldwide.
This event received more media coverage than the combined incidents of nearly 800,000 fossil fuel car fires in the same period.
It highlighted the urgent need for effective fire safety solutions for electric vehicles (EVs).
Motivated by this, Bridgehill collaborated with SINTEF, a leading research institution in Norway, to test if the same fabric we used for buildings could be effective in containing EV fires.
The tests were successful.
Identifying limitations
The quest to create a superior EV fire blanket began when we recognised the limitations of the materials commonly used by our competitors.
Most of them rely on glass fibre, a material that’s widely available globally but only withstands temperatures up to around 530 degrees Celsius.
This level of heat resistance, we found, was insufficient for the kind of safety we aimed to ensure in EV fires.
We explored various options and even consulted with NASA to understand the materials they use in the extreme conditions of space.
This research led us to a recent SpaceX visit where we discussed potential applications of our technology in aerospace.
We discovered that while some manufacturers use silica-based materials, these tend to be brittle and can easily become compromised.
Each material we examined had its own set of advantages and disadvantages.
Through our research and development, we have engineered a fire blanket that significantly outperforms traditional materials.
Our most advanced blanket boasts a heat resistance that is does not only withstand with high temperatures but is also ten times stronger than steel, making it exceptionally durable and reliable in critical situations.
A key breakthrough in our research was the development of textiles made from graphite.
Graphite’s melting point is extraordinarily high, and it becomes especially effective in fire suppression when not exposed to oxygen.
By covering a car with a graphite-based blanket, we rapidly reduce the oxygen level, which is a critical factor in its effectiveness.
Additionally, we’ve incorporated another advanced textile capable of enduring temperatures two to three hundred degrees Celsius higher than traditional glass fibre materials.
At around 800 degrees Celsius, the performance requirements for a fire blanket become critical.
Below this threshold, the reliability of a blanket might not be absolute, but with our blanket we ensure effectiveness even beyond these temperatures.
Quality assurance
Currently, the industry lacks specific certifications for EV fire blankets – but this landscape is rapidly evolving as testing organisations delve deeper into understanding these new technologies.
We anticipate that a diverse range of standards will emerge, reflecting a better grasp of the product’s intricacies.
We are proactive in staying ahead of these developments.
We have established our own laboratory, equipped to test materials at extreme temperatures, up to 1,600 degrees Celsius.
This facility allows us to rigorously test new textiles and coatings, continually refining our products to ensure they meet the highest safety standards.
Our products undergo a variety of tests, tailored to their specific applications and the environments they are designed for.
We focus on both the materials’ ability to withstand high temperatures and their performance under different conditions.
For instance, we have specialised tests for materials exposed to both high heat and pressure, like the conditions experienced during a jet fire.
Designing the fire blanket
Since there are no definitive standards specifically tailored to this type of product, this absence of standards can lead to variability in the quality of products on the market, with some manufacturers opting for off-the-shelf fabrics that might not offer sufficient protection.
We have approached this challenge head-on by conducting extensive testing, far beyond what is typical within the industry.
Since our inception, we have tested our blankets on over 400 actual car fires.
This real-world testing is crucial because fires behave differently outside the controlled environment of a laboratory.
It allows us to observe and measure how our products perform under genuine conditions, which is essential for our development process.
In collaboration with one of Norway’s leading insurance companies, we have been able to test and refine our designs continuously.
This includes creating and assessing up to ten new coatings in response to real fire scenarios, repeatedly subjecting these innovations to the rigours of actual car fires.
Through these rigorous tests, we have learned that the future of fire safety technology may hinge less on the textile fabric itself and more on the development of advanced coatings.
The coatings are often the weak link in fire blankets, failing before the fabric under high temperatures.
We believe that the key to exceeding industry standards lies in innovating coatings that can withstand higher temperatures and provide superior protection.
A unique solution
What truly distinguishes our EV fire blankets is their reusability and the environmentally friendly aspect of their design.
The prevailing trend, particularly in the United States, is for insurance companies to provide fire departments with single-use blankets.
This practice, while effective in the short term, contributes to higher costs and environmental waste.
Our fire blankets are engineered to be ten times stronger than steel, making them capable of multiple uses.
While some may claim their products are reusable, few can match the longevity and resilience of our blankets.
Our testing and real-life applications show that our blankets can be used up to 30 times, if not more.
The future of EVs
With the continuous evolution of the EV market, particularly in terms of battery technology, we anticipate significant changes in fire safety requirements.
A key development is the shift towards solid-state batteries, which promise greater endurance and resilience, even in the event of a crash.
These batteries can last up to two and a half times longer than current lithium-ion batteries, which contain lithium salts.
The next generation of solid-state batteries will utilise lithium metal, which, while offering numerous benefits, also presents unique fire risks due to lithium’s highly reactive nature when it comes into contact with water.
In the event of a fire not originating from the battery itself, the use of water by fire departments could inadvertently ignite the battery.
As a result, the role of Bridgehill’s fire safety solutions, including our fire blankets, is expected to become increasingly critical.
With the upcoming shift in battery technology, traditional firefighting methods like using water may no longer be viable, amplifying the importance of alternative fire suppression techniques.
Our fire blankets, designed to smother fires without the need for water, are poised to play a pivotal role in addressing these emerging challenges.
Looking ahead
At Bridgehill, our vision for the future of fire safety extends beyond temperature resistance.
We’re particularly interested in enhancing the reusability of our fire blankets.
The real advancement, as we see it, lies not in withstanding higher temperatures but in the ability of our products to be effective over multiple fire incidents.
We are dedicating our research and development efforts towards innovating coatings that can sustain multiple exposures to fire without degrading in performance.
A key area of focus for us is the repair and maintenance sector, including garages where EV batteries are often exposed during servicing.
Unlike the enclosed environment of a car, an open battery presents distinct challenges during repair works.
To address this, we’ve developed specialised blankets designed for direct application on open lithium batteries.
We have also developed solutions for wildfires: a blanket that can deflect up to 96% of heat, effectively safeguarding properties.
Warehouses are another significant area of need, especially as more forklifts transition to lithium batteries.
We see the future of fire safety innovation not just in terms of technological advancement but also through the lens of sustainability.
The reusability of our products stands at the forefront of this vision.
By focusing on durable, multi-use solutions, we aim to contribute to the greener aspect of the automotive industry, reducing waste and enhancing safety in equal measure.
This article was originally published in the May 2024 issue of International Fire & Safety Journal. To read your FREE digital copy, click here.