Improving EV sales across the country and the environmental opportunities they offer is now being more fully embraced by Australians. As more councils and businesses develop and establish recharging networks, focus is now on day-to-day recharging. Whilst there is an underlying perception of increased risk associated with lithium-ion batteries it’s important to understand how to mitigate fire risks. Especially in the confined space of garages where the potential of fire is higher.
Lithium batteries are impacted by temperature. The most vulnerable part of the battery is the cathode. Typically, the cathode is made of either nickel manganese cobalt oxide (NMC) or lithium iron phosphate (LFP).
NMC is more cost-effective, but also more prone to thermal runaway. This is a hazardous reaction that triggers sudden fires in LiB batteries. Thermal runaway is often caused by overcharging, overheating, damage, or defects. Once started it can cause major fires that are difficult to extinguish.
Australian conditions different to Europe
One of the unknowns of EV’s in an Australian context is that our temperatures are often much higher than in Europe and America. Therefore the experience in terms of fire incident recording with LiBs is relatively new. A ‘Conversation” November 24 study of 100 brands and models of EVs revealed that 90% of those studied used NMC batteries.
An important issue for EV car manufacturers is the battery’s weight to efficiency ratio. In the models studied the ratio for NMC batteries was 6.74 kg per kWh. Only slightly heavier than LFP batteries at 6.51 kg per kWh. Studies on how quickly they burn, or the Heat Release Rate (HRR), reveal a notable difference in fire behaviour between NMC and LFP batteries as capacity increases. Essentially NMC batteries appear to pose greater fire risks at higher capacities than LFP batteries. Based on the study undertaken by article authors Gomez, Bin Mohd Tohir, and Debeure.
Beyond just battery type and capacity, the study also explored whether the level of charge in a battery, known as the state of charge (SoC), influenced the power released during a fire. The results showed that fire intensity remained stable. However, at full charge fire strength surged, aligning with the experiences of recorded fires occurring during vehicle charging.
The authors concluded that effective fire prevention systems at charging stations, particularly underground, to mitigate risks associated with charging EVs, especially those with high-capacity NMC batteries.
Ecobatt ahead of the curve
Ecobatt is ahead of the curve in looking at those electric vehicles that are damaged or involved in collisions. Arguably, with the only safe transport containers in the country damaged EV vehicles can be moved in a safe and efficient way. Special twenty -foot containers allow an impacted vehicle to be winched safely into the containers and be transported. The container also has a sophisticated fire suppression system to reduce the risks of fire occurring during transport
Ecobatt Safety also has the Australasian rights to leading international brands, ESE, Bebat and Cellblock. These products provide fire suppression capabilities that assist in safe recharging and containment of potential thermal runaway fires.
A new URT lithium battery recycling plant will be commissioned in 2026 by the group, which will increase capacity to process 30,000 tonnes of batteries per annum. Its main objective will be to urban mine critical minerals from lithium batteries including those recycled from older EVs.
