CATL reports successful testing of a 350-Wh/kg battery for eVTOLs.

CATL has passed a rigorous safety test with a battery system for electric aircraft. Two adjacent cells were deliberately triggered to overheat, but according to the manufacturer, the incident did not spread to other cells.

The Chinese battery manufacturer has developed a system for passenger eVTOLs that uses prismatic cells with an energy density of 350 Wh/kg. The company claims this is the world’s first aviation battery system using prismatic cells at this energy density level to pass such a safety test.

According to a report by the portal CN EV Post, two adjacent cells were simultaneously targeted for thermal runaway in both the center and corner areas of the battery pack. The report states that in none of the tests did the “thermal runaway” spread to other cells. It is standard practice in such tests to trigger only a single cell; triggering two adjacent cells at once intensifies the test conditions accordingly. The Chinese aviation authority, CAAC, was also involved in the manufacturing, inspection, and testing of the cells and battery system, per the report. This intensified testing is intended to establish a basis for meeting safety requirements in civil aviation, though passing this test does not yet guarantee approval for commercial flight operations.

CATL has already labeled the battery system as ready for mass production. The first customer is set to be the Chinese eVTOL developer AutoFlight. The relationship between the two companies goes beyond a simple supply agreement: in August 2024, CATL became a strategic investor in AutoFlight with an investment of several hundred million dollars.

For electric aircraft, energy density is a particularly crucial factor, as the weight of the battery directly determines flight range and payload capacity. The 350 Wh/kg figure is significantly higher than what current vehicle batteries achieve. At the same time, the aviation industry has extremely high safety requirements, which is why preventing thermal spread within the battery pack is essential for the system’s approval.

CATL Expanding Beyond Electric Vehicles

With aviation, CATL is entering another application area for its battery technology. In its core business of vehicle batteries, the company has further strengthened its leading position: According to SNE Research, in the first half of 2026, CATL batteries with a capacity of 242.7 GWh were newly installed in electric and hybrid vehicles worldwide — 25.3 percent more than in the previous year, accounting for 39.9 percent of the global market share. Together with BYD, CATL now covers more than half of the global market. Aviation represents the next step in the company’s diversification efforts, which also include working on solutions for electric ships. However, before CATL’s new battery system can actually transport passengers commercially by air, further approval and certification processes are required despite its readiness for mass production.