Supplementary Evidence – Robin Brundle – Chairman Technology Minerals PLC (ELV0139)
Could you send through your top three specific recommendations in the area of recycling, regulation, and EV end-of life waste management?
- Separate by chemistry the evidence of end-of-life batteries. In essence stop lead-acid batteries from being used to evidence Li-ion battery end of life.
- Enforcement of current legislation and near-term legislation changes by increasing the resources within the EA.
- Legislate to prevent repaired batteries from being sold or re-used unless certified/warranted by the OEM.
Why do some catch fire and others don't? What makes them more vulnerable to catching fire? Is there more of a risk of fire than with ICE vehicles and can this risk be eliminated?
- In the whole of 2022, there were 18,991 road vehicle fires in the UK. This represented a 4.7% increase from 2021 (18,139 fires) but an 18% decrease from 2017 (23,024 fires) and a 10% decrease from 2012 (21,176) [1]. Clearly, the long-term trend is downward, even though battery powered vehicles (including e-scooters, e-bikes, EVs) have come into prominence in the last few years.
- Battery related fires accounted for 239 fires of the 18,991 total fires in 2022, representing 1.25% of all the fires. The 239 fires were not all EVs as the figures also include e-scooters, e-bikes, electric motorbikes, electric forklift trucks etc [2]. The data also does not differentiate between plug in vehicles or hybrid vehicles
- From 2017 – 2022, there were 735 incidents of battery related fires across the UK. London had the highest density of battery related fires; the chart below shows breakdown of the type of vehicle in London [2]
Chart from [2]
- Data from the US shows that hybrid vehicles are the most prone to fire. For every 100,000 vehicles sold, hybrid vehicles caught fire at 3474.5 per 100k sold, gasoline vehicles at 1529.9 per 100k sold and EVs at just 25.1 per 100k sold [3]
- Since 2013, there have been 204 cases of Tesla’s catching fire worldwide [4]. Given that Tesla has sold over 4 million vehicles worldwide, the rate of Tesla vehicles catching fire is extremely low.
- Clearly, EVs are safer than conventional vehicles when it comes to catching fire. Hybrids on the other hand are not and this may be due to the combination of high voltage electricity and gasoline. In the event of a crash, any gasoline leakage or vapour can easily catch fire if the high voltage battery creates a spark at any junction along the HV cabling of the car
When EVs do catch fire, they are harder to put out as they contain more chemical energy. The chart below shows the amount of chemical energy in a 50L tank for ICE vehicles Vs an 85kWh battery pack (based on a Tesla Model S). As shown, most of the energy in a battery pack is the chemical energy from the chemicals within the battery that allows it to work. Chemicals such as the graphite, electrolyte, plastics all lead to the intense fires caused by the battery burning. The electrical energy, which accounts for less than 10% of the total energy acts as the spark, setting off the chemical energy. The fires are hard to put out as the batteries cause a chain reaction with one heating up the one next to it, etc.
Source: [5] WMG
Batteries catch fire for a number of reasons.
- When the car is involved in a crash and the battery has been damaged
- A battery pack can have hundreds or thousands of cells, the more cells there are, the more likely something can go wrong
- A pack has thousands of electrical connections, if any one of these connections experiences a fault, it can lead to a fire
- The customer can abuse the battery by overcharging it or over-discharging it or over-burdening it
- Overheating of the battery can cause fires
- Use of impure chemicals within the batteries – this is a quality control issue and more likely to be an issue associated with cheap imported EVs from certain parts of the world. This could cause a problem in the near future as the UK is Europe’s largest importer of Chinese EVs
How can we eliminate EV fires? EV fires can never truly be eliminated as the battery will always contain enormous amounts of energy and anything that contains that much energy has the ability to release that energy in a short space of time – i.e., fire. The risk can be reduced firstly by understanding what it is that causes the fire and then designing the battery to avoid that issue. This has already led to safer EVs but now new mechanisms of how the EVs are catching fire are beginning to come out and such mechanisms are less well understood as of now. Through better design and the use of less volatile chemistries, EV vehicles will become even safer than they already are (as shown by the statistics).
[2] https://cesafety.co.uk/news/data-reveals-extent-of-electric-vehicle-fires-around-the-uk/
[3] https://www.autoweek.com/news/a38225037/how-much-you-should-worry-about-ev-fires/
[4] https://www.tesla-fire.com/
[5] Anwar Sattar. Recycling of Lithium-ion Batteries. Warwick Manufacturing Group (WMG)