Revealing the Degradation Mechanism of Lithium-Ion Batteries for Electric Aircraft.

The widespread adoption of electric vehicles has spurred the exploration of airworthy lithium-ion batteries (LIBs) for electric-powered aircraft. However, LIBs used for aviation exhibit rapid aging and shortened service life due to the harsh conditions of aviation, posing significant risks to flight safety. In this study, a comprehensive analysis is conducted under simulated flight conditions to reveal the degradation mechanism of aviation batteries. Low-temperature and low-pressure lead to a sluggish kinetics and hinder thermodynamic process. As the reversibility of Li-ions insertion and extraction is deteriorates, residual Li-ions accumulate and plated-Li on the anode, accelerating the aging process and arising the issue of internal short circuits. Additionally, the interatomic distance of Ni-coordination induces significant stress variations, which drives an expanded occupation of porosity in the electrode under flight conditions, with 2.13% void spaces of cathode and 13.39% of anode. The formation and growth of cracks elongate the charge transfer pathway, increasing resistance and reducing rate capability. As a result, this study quantifies the degradation mechanisms of aviation batteries and establishes the relative impact weights of temperature and pressure factors, offering critical insights for optimizing future electric aircraft power battery designs.