Globally Recognised Safety Features Assure Safe Travel Amidst The News Of EVs Catching Fire

Smit Kant Raturi Jul 27, 2022

The news of EVs catching fire from different parts of the country flared up questions among EV enthusiasts regarding the tenability of such vehicles. Last month, a short video clip of an EV on fire was shared from Pune, followed by another similar footage in Vellore (Tamil Nadu). The stakeholders of the EV industry and their customers have expressed immense concern towards such incidents. The poor thermal management system of EV vehicles coupled with extreme summer temperature has been anticipated as the cause of such EV fires by many. However, owing to such instances, the public at large is starting to talk about better safety mechanisms and protocols while using EV vehicles.

But are problems pertaining to thermal management the entire story? Well, not really. Let us delve deep into understanding the issue and reflect on globally recognized safety patterns that bring down the prevalence of EV fires.

What Starts The Fire?

Climate change, indeed, is an alarming threat to the entire genus of living species. However, the realisation that the hot, sultry summer is the cause of EV fires is a misconception. The fact that EV-comprising lithium-ion (Li-ion) cells require a temperature close to a few hundred degrees celsius before suffering a ‘thermal runaway incident’ reinstates that these generally conceived notions do not cause EV fires. There may be an overall negative impact on the performance and short life of the EV due to inadequate thermal management systems, but they do not cause fires.

In recent times, most of the EV fires have been due to short circuits leading to uncontrolled current. Under such circumstances, the cells heat themselves beyond 100 degrees celsius. One of the major causes of internal short circuits is the poor cell quality of the battery. Limitations in the manufacturing of the battery cause the accidental connection of cathode and anode, which fails to maintain the regular path of current. Therefore, unless the battery packaging is solid, there is a chance of fire due to a short circuit. Another common cause of EV fire is overcharging. The maximum voltage for NMC (nickel, manganese and cobalt) is 4.2V, and for LFP (lithium ferro phosphate) is 3.6V. Overcharging even marginally by 0.05V shall initiate the formation of dendrites, which cause an internal short circuit by connecting the cathode and the anode.

Globally Recognized Safety Features and Preventive Measures

Considering the safety concerns of driving an EV, adopting various failsafe measures shall reduce the possibility of EV fires. A temperature measurement system with a built-in sensor can be incorporated, automatically cutting off power and immobilising the vehicle if the cell picks up a certain temperature. In emergencies, the system also pushes a notification to the customer to take the vehicle to a secluded place if there is a possibility of the vehicle catching fire.

Measures can be taken to prevent short-circuiting from overcharging too. There are smart charges available that can communicate with the battery pack to get the data on temperature and battery health. However, it must be noted that EV batteries were never formulated to suit Indian climatic conditions or the usage patterns of Indian vehicles. Therefore, a sustainable solution to such a problem would either require building battery chemistries from the ground up, on par with the climatic conditions of India or investing in upgrading to fill in the gaps in existing technology to efficiently suit the customer's usage needs at large.

Conclusion

While EV charging infrastructure is still under development, Original Equipment Manufacturers (OEMs) should self-regulate to fill their existing shortcomings. This may entail a re-evaluation of their existing vehicles and their battery systems. Only then can we make the EV sector a haven of safety for existing and potential EV enthusiasts.