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.
