Electric vehicle safety : concerns and considerations

As electric vehicles (EVs) trend from being niche to mass scale and the lines between EVs and their combustion engine (ICE) counterparts get blurred in terms of usability, consumers, automakers, governments and fire departments continue to have some apprehensions.

Amongst these, incidents of battery fires and explosions have caught considerable media attention. Big automakers are amidst this challenge which highlights that as car companies lower the costs of batteries and address range anxiety issues around EVs, safety considerations will be paramount. As with any new technology, it is important that the industry implements best practices and safety standards and deploys the right combination of battery chemistry, cell design and battery management system to minimize risks of such incidents.

Since EVs have not been around for too long, it may be hard to corroborate their safety profile with accurate data and reliable information and therefore make a sound comparison with ICE vehicles. Moreover, ICE vehicles have been around for well over a century and a lot is understood about fire risks they present and what it takes to mitigate them.

Li-ion batteries, and as a result EVs, are the safest technologies available today if used with proper risk management.

Fundamentally, lithium-ion batteries, and as a result EVs, are the safest technologies available today if used with proper risk management. Potential EV consumers are lost in the jargon of thermal runaway, spontaneous ignition, battery management system and find themselves in a quagmire of ambiguity around facts, figures, science and commercial interests which impacts decision making and EV uptake.

An example of lack of reliable information when it comes to EV fires is what causes battery fires. Li-ion battery fires are never spontaneous but rather caused by either physical damage, such as in a car crash, or because the batteries have exceeded their safe operating temperature which is possible if there was a catastrophic simultaneous failure of the battery management and thermal management systems.

Different cathode chemistries have different threshold temperatures at which a rapid decomposition can occur, but advancements in single crystal technology and passivating coatings on the cathode particle surface has dramatically increased the chemical stability of the cells even without cobalt.

In the case of a rare electric vehicle fire, it is the combustion of the liquid electrolyte that poses the greatest safety risk due to hydrogen fluoride gas being a product of combustion. This situation can be overcome with the development of new non-flammable electrolytes including the future solid-state electrolytes.    

©Alessio Lin - Unsplash
©Alessio Lin - Unsplash

Given that the EV industry is still in its initial stages of development, the most important concerns around its uptake are bringing the cost down and addressing range anxiety.

Safety may not be the first consideration, but it is the most important one. Safety will need to be understood from a vantage point that not only looks at Li-ion batteries of EVs but the entire ecosystem, such as charging stations and stationary grid-scale storage systems. Several considerations such as neighboring environment, proximity to populations and countermeasures undertaken by fire first responders will need to be factored in to minimize the impact of such fire risks.

Regulators around the world are pushing towards greater research to understand battery fires while simultaneously urging automakers to improve emergency response guides and fill any information gaps to mitigate risks of fire incidents or any other safety breaches.

Unarguably, understanding the safety profile of EVs and development of risk mitigation strategies is one of the main planks of EVs achieving the same comfort level as ICE. Once EV’s attain maturity, it is safety that will determine their dependability and reliability.