Characterization of Li-ion Batteries under Low Pressure for Electric Air Mobility

The aviation industry is committed to reducing emissions caused by the propulsion system through electrification that can enable a more sustainable transportation system. Lithium-ion batteries are one of the most promising enabling technologies for the transition to electrified air mobility. Despite their potential advantages, the operation of Li-ion battery cells in aircraft applications can pose significant hazards, especially in high-altitude and dynamic environmental conditions. Pouch cells, in particular, are known to be more vulnerable to failure modes due to their soft case, which can be prone to swelling mechanisms and electrolyte venting. Such failure modes can result in hazardous scenarios, such as thermal runaway and fires. Given that pouch cells are compact, lightweight, and capable of delivering high energy and power, they are increasingly being considered for electrified aviation applications. Therefore, it is crucial to establish a standardized testing procedure that can emulate the environmental conditions encountered in aviation. The goal of such a procedure is to investigate and characterize the performance of Li-ion battery cells at high altitudes, where environmental pressure and temperature can vary significantly. This paper aims at providing a testing procedure to characterize the performance of pouch cells for propulsion under low-pressure conditions, considering RTCA standard requirements as a reference. An experimental test setup able to control and monitor the cell temperature, external load, and environmental pressure is developed in order to conduct tests in a controlled environment.