As electric vehicle (EV) production ramps up, the fire service is still grappling with how best to approach EV fires, which are not as straightforward as internal combustion engine (ICE) fires.
As those efforts continue, a new study published by Clemson University showed researchers’ successful attempt to design a “self-extinguishing rechargeable battery.”
The research premise was to determine if any existing fire extinguishing agents could be placed into the lithium-ion (Li-ion) battery without interrupting the flow of the Li-ion charged molecules from the anode to cathode under normal operating conditions and serve to self-extinguish the battery if it went into thermal runaway.
Using Novec 7300 – a low-toxicity, environmentally-friendly, nonflammable electrolyte – prevented the flames from spreading from one battery cell to the next by transferring heat away from the battery pack.
Researchers continue to test other alkali metals that are more readily available than lithium, including potassium and sodium. The new goal is to develop not only a self-extinguishing Li-ion battery, but to find an electrolyte that will also suppress fires in both potassium- or sodium-ion batteries should they be used in the future.
EV alternatives: Compressed hydrogen
To avoid the issue of EV fires, some researchers are experimenting in other areas as well. Instead of an EV, Toyota, in partnership with Yamaha, designed a new V8 combustion engine that runs on compressed hydrogen, with virtually no environmental impact except water as its only by-product.
However, Toyota’s technological advancement raises a new question: Will compressed hydrogen create another set of issues for the fire service to deal with during a vehicle fire? It’s certainly known that hydrogen burns at a high temperature with a nearly invisible flame. (In fact, I can remember training on such fires at the former Fernald Atomic Energy facility. A firefighter at the front of the advancing crew would extend a broom as they moved. When the broom started to burn, we knew where to attempt to control the fire, as extinguishment meant turning off the hydrogen at the source, if possible.)
To answer that question, Toyota’s shared three hardened and tested fuel tanks where hydrogen is stored in liquid form. Researchers believe this new vehicle configuration will be less susceptible to fire or damage, as well as an environmentally friendly alternative to electric vehicles.
The future of vehicle science
So, while we may have a long-term answer to Li-ion battery fires with the self-extinguishing fire agent, there are still questions, like how to dispose of the batteries in a way that’s safe for the environment. Though hydrogen appears environmentally friendlier and more plentiful than lithium-ion, we in the fire service may need more convincing from manufacturers like Toyota on the fire potential in vehicles using compressed hydrogen.
Stay safe.
