CATL Aviation Battery System Passes Dual-Cell Thermal Propagation Test

Contemporary Amperex Technology Co Ltd (HKEX: 3750), the world's largest power battery maker, said its CATL aviation battery system developed for passenger eVTOLs (Electric Vertical Takeoff and Landing) has passed a verification test demonstrating no thermal runaway propagation when two adjacent cells were triggered. The result represents a significant safety milestone for aviation batteries, where high energy density creates demanding thermal management requirements. The company said the system is the world's first aviation battery system using prismatic cells with an energy density as high as 350 Wh/kg to pass this type of test.

During the verification test, two adjacent cells were simultaneously triggered at different locations within the battery pack, including the middle and corner areas. No thermal propagation occurred during the test, according to the company. The production, inspection and testing of both the cells and the battery system were witnessed by designated representatives of the Civil Aviation Administration of China (CAAC). CATL said the verification provides groundwork for passenger eVTOL aircraft to meet civil aviation safety standards. The result is particularly relevant to aviation because thermal runaway propagation remains one of the core risks associated with high-energy-density battery systems.

Dual-Cell Testing Raises Aviation Battery Safety Requirements

The industry typically verifies that thermal propagation does not occur after a single battery cell is triggered. CATL's test introduced a substantially more demanding condition by triggering two adjacent cells simultaneously at different locations in the battery pack. The company said this test showed no thermal propagation, including when cells positioned in the middle and corners of the pack were triggered. Such testing is important for aviation applications because battery safety requirements are especially sensitive when high-energy-density systems are deployed in aircraft. The verification therefore addresses a critical safety challenge associated with the use of advanced battery technology in passenger eVTOL operations.

Battery System Ready for eVTOL Mass Production

CATL said its aviation battery system is ready for mass production and will first be used in passenger eVTOL aircraft from Autoflight, a company backed by CATL. The move extends CATL's battery technology beyond conventional electric vehicles into emerging transportation applications. The company is seeking to expand its technology into additional areas, including electric vessels and electric aviation. For passenger eVTOL manufacturers, battery performance and safety are central to the development of commercially viable aircraft because the technology must combine high energy density with stringent thermal safety requirements.

CATL and Autoflight Expand eVTOL Partnership

In August 2024, CATL signed an agreement with Shanghai-based Autoflight to become a strategic investor, exclusively investing hundreds of millions of dollars in the eVTOL maker. It was the first publicly disclosed CATL investment in an eVTOL company. The partnership subsequently expanded into integrated infrastructure for eVTOL operations. In November last year, the two companies jointly unveiled a floating vertiport, described as a battery-powered vessel integrating an eVTOL takeoff and landing platform with photovoltaic energy storage and charging systems. The project was billed as the eVTOL industry's first integrated sea-air solution.

Autoflight Builds Commercial eVTOL Position

Autoflight was founded in 2017 and is one of the earliest companies in China's eVTOL sector. Its cumulative commercial orders reached 2,000 aircraft as of November last year, highlighting the company's position in the emerging commercial eVTOL market. CATL's decision to make Autoflight the first customer for its aviation battery system connects the battery manufacturer's high-energy-density technology with an eVTOL platform that already has a substantial order base. The relationship also provides CATL with a direct route to apply its battery technology in passenger aviation as the eVTOL industry develops toward commercial-scale operations.

CATL Extends Battery Technology Beyond Electric Vehicles

CATL's aviation battery development forms part of a broader effort to extend its battery technology beyond conventional electric vehicles. The company has been pursuing opportunities in areas including electric vessels and electric aviation, where battery energy density, reliability and safety are important technology requirements. Aviation applications place additional demands on battery systems because thermal events must be tightly controlled within aircraft environments. The latest verification result therefore demonstrates CATL's focus on adapting advanced battery technology for applications where high energy density must be combined with stringent safety performance.

CATL Maintains Strong Global EV Battery Position

CATL remains the world's largest battery maker, with its existing electric vehicle battery business providing a substantial industrial base for expansion into new mobility sectors. Global EV battery installations reached 242.7 GWh in the first half, up 25.3% year-on-year, according to South Korean market research firm SNE Research. CATL held a 39.9% market share during the period. The company's expansion into aviation and marine applications therefore builds on an established position in EV batteries while opening potential new markets for high-energy-density battery systems and related technologies.

Frequently Asked Questions

What did CATL's aviation battery system test demonstrate?
CATL's aviation battery system demonstrated that two adjacent cells could be simultaneously triggered without causing thermal runaway propagation, representing a demanding safety verification for high-energy-density aviation batteries. The system uses prismatic cells with an energy density as high as 350 Wh/kg and was tested with designated Civil Aviation Administration of China representatives witnessing production, inspection and testing. CATL said the system is ready for mass production and will first be used in passenger eVTOL aircraft from Autoflight, supporting efforts to meet civil aviation safety standards.