Influence of Low Pressures on the Performance of Lithium Ion Batteries for Airplane Applications

Abstract

The electrification of aircrafts is a recent trend in aviation and with it the use of batteries as energy carriers at high altitudes. These batteries can be exposed to low pressures and it is crucial to understand the influence of low pressures on the battery behavior. In this study, commercially available lithium ion batteries were examined experimentally at low pressures down to 25 kPa. Discharge curves and impedance measurements were performed at 23 °C for each pressure level. Cylindrical Lithium Nickel-Cobalt-Aluminum Oxide (NCA) and Iron-Phosphate (LFP) cells did not show any pressure influence, while Lithium Nickel-Manganese-Cobalt Oxide (NMC) pouch cells showed some performance variation with reduced pressure. The ohmic resistance increased by around 0.1 mΩ per 25 kPa and at 25 kPa the charge transfer impedance increased for low SOCs. The results show that no strong change in performance is to be expected for low pressure applications in airplanes, however further research is needed with respect to long term effects, thermal management and safety.