CATL has announced a significant milestone in aviation energy storage, confirming that its 350 Wh/kg battery system has successfully passed a rigorous thermal runaway propagation test. This development marks a critical advancement for the airworthiness certification of electric vertical takeoff and landing aircraft.
The test protocols were particularly demanding, requiring the battery to withstand the simultaneous triggering of two adjacent cells without any thermal propagation. According to the company, this is the first time an aviation-grade battery using prismatic cells at this specific energy density level has successfully cleared such a test. Representatives from the Civil Aviation Administration of China (CAAC) oversaw the verification process, which included inspections of both production and testing procedures.
The technical achievement underscores a potential path toward safer high-capacity power systems for the burgeoning eVTOL market. CATL has confirmed the technology is now ready for mass production. The battery system is slated for initial integration into passenger aircraft produced by Autoflight, an eVTOL manufacturer supported by the battery supplier. This development provides a clearer benchmark for safety standards as the industry continues to navigate the transition toward commercial electric aviation.