What are eVTOLs?
Standing for 'electric Vertical Take-Off and Landing vehicles', eVTOLs are playing an increasingly important role in ensuring sustainability within the aviation sector. They are billed to be at the core of reshaping the industry, with businesses around the world investing in their development and associated infrastructure.
This is demonstrated by the UK government's Future of Flight Action Plan, published in March 2024. eVTOLs are at the heart of this Plan due to their sustainability and cost-effectiveness. They are less expensive, noisy and polluting than helicopters. The Flight Action Plan outlines aims for eVTOLs to be airborne as flying taxis in the next two years, and to become commonly used for transporting passengers and cargo by 2028.
How do eVTOLs Work?
The vehicles are operated by electric motors and propellers that enable them to take off and land vertically, hence their namesake-acronym. Batteries, typically lithium-ion, give them the energy they need to operate, and the configuration of the rotors allows the craft to move, tilt, and lift at all the required angles. eVTOLs are directed by in-built, autonomous computer systems, or, if not fully autonomous, through pilot code.
Originally conceptualized in 2009 by NASA engineer Mark Moore, eVTOLs have been a work in progress for many years. Thanks to ongoing investment and continued R&D, they are now becoming practically applicable as the greenest addition to the aviation sector.
Transforming the Aviation Industry
eVTOLs are incredibly exciting for the potential they offer to revolutionize the aviation industry. Vertical take-off, pilotless eVTOLs and aerial taxis are the stuff of sci-fi – yet they could soon become a day-to-day reality!
For example, at the forefront of the development in the eVTOL sphere is German-based Lilium, who are working on the certification of their 7-seater Lilium Jet. They are aiming to have this airborne and in commercial operation by as early as 2025. In another example, earlier this year, Vertical Aerospace received £8 million of government funding to support development of their VX4 eVTOL aircraft. The investment will cover the propeller and propulsion costs needed to make the vehicle lighter and quieter than previously developed technology.
These futuristic machines open up new opportunities for individuals living remotely, off-grid, or where old infrastructure affects connectivity. eVTOLs could be central to lessening congestion in heavily populated areas, while aerial taxis offer exciting prospects for use within the emergency, military and charitable sectors as sustainable tools to serve the public.
What About Thermal Runaway? Are eVTOLs Safe?
In the buzz surrounding eVTOLs’ capacity to transform the aircraft industry, the potential safety risks could be glossed over. However, it is important to outline the potential risks to ensure the safety of all those involved in their development, operation, and use.
Aerial taxis are battery powered - usually by lithium-ion batteries - and these come with a set of hazards. In the instance of a pressure build up, where the batteries produce more heat than they can efficiently distribute, thermal runaway can occur. If this happens, the excess heat energy and pressure may be released in an uncontrollable explosion and fire. Thermal runaway is a specific risk during lithium-ion battery charging or should a crash or other accident occur.
It is crucial to mitigate these battery fire risks, particularly in the case of powering up eVTOLs, when a large amount of power needs to be drawn from the li-ion battery in a short space of time during take-off.
Mitigating Li-ion Battery Fire
With these risks in mind, it is crucial to mitigate the possibility and effects of thermal runaway and li-ion battery fires onboard eVTOL aircraft. There are a range of safety measures that manufacturers can take to mitigate the risks of lithium-ion battery fires. These include rupture discs.
OsecoElfab produces a range of specialist rupture discs for lithium-ion batteries. The OE Lion™ brand offers a series of high-tech solutions, each of which is fully customizable to handle the unique and often challenging environments in which lithium-ion batteries operate in electric and hybrid vehicles. The rupture discs offer fast, reliable and accurate emergency pressure relief. There is the option of adding a breather membrane to each disc for ongoing pressure equalization. Combining these two pressure safety features in a single device enables battery manufacturers and integrators to design safer, simpler and more cost-effective li-ion batteries.
For more information on our OE Lion™ range please visit our product pages to view the full OE Lion range and learn more about our lithium-ion battery pressure safety solutions for eMobility.
