Battery safety in aviation

Whether in personal devices or as a power source for future electric aircraft, the safety of batteries is a critical factor in aviation. The increasing number of incidents shows how great the risks are.

Fraunhofer EMI is working with Airbus and EASA on innovative solutions to prevent battery fires and make aviation safer.

Thermal runaway: Why battery fires in airplanes are particularly dangerous

In recent years, the number of incidents involving batteries catching fire in home storage units or electric cars has risen alarmingly. These incidents are often due to production errors, improper handling or overcharging and result not only in material damage but also in risks to personal safety. This phenomenon, also known as “thermal runaway”, which occurs particularly in lithium-ion batteries, is critical and can lead to dangerous situations. It describes an uncontrolled rise in temperature in the battery cell that can trigger a chain reaction, causing the battery to overheat, burn or even explode. This issue is particularly relevant in aviation, as a battery fire in an aircraft can have catastrophic consequences. The confined space in the cabin, limited fire-fighting resources and long flight times to the nearest airport make fires in airplanes particularly dangerous. The effects of a fire in the air include danger to passengers and crew and the possibility of loss of control of the aircraft. It is therefore crucial to understand the risks of thermal runaway and the likelihood of occurrence in order to derive appropriate safety measures to ensure safety in aviation.
 

How dangerous are risk factor personal electronic devices?

Every passenger carries one or more personal electronic devices such as cell phones, tablets or notebooks. These devices often contain lithium-ion batteries, which can thermally runaway if damaged, overheated or faulty. An example of the risks of smartphone batteries occurred in 2016, when the FAA (Federal Aviation Administration) banned Samsung Galaxy Note 7 cell phones due to reports of overheating and fires. After numerous incidents of the devices bursting into flames or exploding, Samsung initiated a global recall. The FAA then issued a regulation prohibiting passengers from bringing the Galaxy Note 7 on board airplanes. This heightened concern about the safety of lithium-ion batteries in portable devices. 

This incident highlights the need to raise safety standards for batteries in portable electronic devices. This includes raising passenger awareness of potential risks to ensure safety on board. 

Together with the Fraunhofer Institute for Building Physics IBP and Airbus, Fraunhofer EMI is investigating the risks posed by battery fires in modern smartphones or tablets on board aircraft. This research project, called LOKI-PED, is funded by the European Union Safety Agency (EASA). 

The future: (hybrid) electric propulsion

The climate-neutral aviation of the future will be significantly shaped by technological innovations, in particular hybrid-electric and all-electric propulsion systems. These propulsion systems are crucial for achieving the ambitious goals of Flightpath 2050, which aims to reduce CO2 emissions from aviation by up to 75 %. In view of the growing challenges of climate change and the need to minimize the environmental impact of aviation, hybrid-electric engines offer a promising solution. They combine the efficiency of conventional engines with megawatt-class electric drives. Fully electric drives go one step further by enabling emission-free mobility. These developments are not only technologically fascinating, but also necessary to create a sustainable aviation industry that meets the requirements of the future. 

Megawatt drives in aircraft: enabling change with batteries

Electric flight with megawatt-class drives poses a considerable challenge for battery technology, as the required energy density, weight efficiency and charging times far exceed the capacities currently available. For the realization of all-electric aircraft that offer greater ranges and payloads, batteries must achieve an energy density that is far higher than that of today’s lithium-ion batteries. In addition to issues of weight efficiency and charging times, the service life and safety of these high-performance batteries pose major challenges for research and development.

With its combination of outstanding technical test facilities for investigating the thermal runaway of large batteries, including the ability to look inside the battery during thermal runaway using imaging X-ray techniques, and its expertise in simulating the thermal runaway of battery cells, modules and packs, Fraunhofer EMI is ideally positioned to support the aviation industry on the road to electric flight. 

The aviation industry benefits from the expertise of the scientists at Fraunhofer EMI, which has been built up over many years in the context of the mobility transition. A first reference project in which this knowledge is being transferred to aviation is the HYDRO project funded by the Federal Ministry of Economic Affairs and Climate Action as part of the German government’s aviation research program Lufo VI-3. As part of this project, EMI scientists are working with engineers from Airbus Helicopters to investigate the safest way to integrate large batteries for an electric motor into a helicopter.