CATL tests 350 Wh/kg battery for eVTOLs
CATL has passed a demanding safety test with a battery system for electric aircraft. The manufacturer says thermal runaway did not spread to other cells after two adjacent cells were deliberately triggered simultaneously.
Chinese battery manufacturer CATL has developed a battery system for passenger eVTOLs using prismatic cells with an energy density of 350 Wh/kg. According to CATL, it is the world’s first aviation battery system with prismatic cells at this energy density to pass the specified safety test.
According to a report by CN EV Post, two adjacent cells were deliberately triggered into thermal runaway simultaneously, both in the centre and at the corners of the battery pack. In none of the tests did the thermal runaway propagate to other cells. Such tests typically trigger only one cell, meaning that simultaneously triggering two adjacent cells significantly increases the test conditions. China’s aviation authority CAAC was involved in the manufacturing, inspection and testing of the cells and battery system. The stringent test is intended to lay the groundwork for meeting civil aviation safety requirements, although passing it does not constitute approval for commercial flight operations.
CATL says the battery system is ready for series production, with Chinese eVTOL developer AutoFlight as its first customer. The relationship between the two companies extends beyond a supplier agreement: in August 2024, CATL invested several hundred million dollars in AutoFlight as a strategic investor.
Energy density is particularly important for electric aircraft, as battery weight directly affects both range and payload. At 350 Wh/kg, CATL’s aviation cells significantly exceed the energy density of current EV batteries. At the same time, aviation imposes particularly stringent safety requirements, making the prevention of thermal propagation within the battery pack a key factor in its eligibility for certification.
CATL expands beyond electric vehicles
With aviation, CATL is expanding its battery technology into another application area. In its core vehicle battery business, the company has further strengthened its leading position: according to SNE Research, CATL supplied 242.7 GWh of batteries installed in electric and hybrid vehicles worldwide in the first half of 2026. That represents an increase of 25.3 per cent year-on-year and a global market share of 39.9 per cent. Together with BYD, CATL now accounts for more than half of the global market.
Aviation represents the next step in CATL’s diversification, which also includes battery solutions for electric ships. However, despite the aviation battery system being ready for series production, CATL must complete further approval and certification steps before it can be used to carry passengers in commercial operations.