Weiran Jiang, Vice President of R&D at Farasis Energy: "The eVTOL battery has completed over 10,000 real-world test verifications and will be supplied in bulk this year."

In the low-altitude sector centered around eVTOLs, battery companies have made their moves earlier than the policy signals. It is worth noting that power batteries for low-altitude aircraft have all-round requirements for battery performance, with the difficulty level several orders of magnitude higher than that of batteries for EVs. Therefore, cooperation and installation in fields such as eVTOLs can better demonstrate a company's R&D and manufacturing capabilities.

"Farasis Energy's eVTOL batteries have undergone over ten thousand real-world tests and validations, and have entered Phase IV certification for aviation safety by the US Federal Aviation Administration (FAA)." Recently, at the Electric Aviation and Next-Generation Battery Technology (CIBF2025 Shenzhen) Symposium jointly hosted by the Power Battery Application Branch and China Battery Network, Jiang Weiran, R&D Vice President and Dean of the R&D Institute of Farasis Energy (Ganzhou) Co., Ltd., stated.

Thirteen Years of Layout: eVTOL Batteries to Be Supplied in Bulk

As one of the pioneers in the global manufacturing of green aviation power batteries, Farasis Energy began its R&D layout for eVTOL power batteries in 2012, completed sample supply in 2020, achieved mass production and installation of its first-generation products and verification of its second-generation product system in 2022, and assisted its customers in becoming the first eVTOL company to obtain FAA airworthiness certification.

"In 2022, we collaborated with low-altitude aircraft companies in China, Europe, Southeast Asia, and South America to verify our second-generation aviation battery system, and in 2023, we became the world's first battery company to deliver eVTOL products to terminal customers." Jiang Weiran stated that in 2024, Farasis Energy's eVTOL batteries have been delivered to the top five domestic complete aircraft customers. Currently, the product has also received orders from well-known domestic research institutes, AeroHT Technology, and several other leading domestic low-altitude aviation enterprises.

The outstanding performance of Farasis Energy's power batteries for the low-altitude sector, particularly in the eVTOL field, has also garnered widespread attention in the flying car industry. In March this year, Farasis Energy received a nomination development notice from a leading domestic flying car enterprise. According to informed sources, after a comprehensive analysis of Farasis Energy's quality assurance system, technological R&D, production organization capabilities, and other factors, the flying car R&D enterprise decided to choose Farasis Energy as the supplier of high-voltage power batteries, high-voltage connectors, and low-voltage connectors for its next-generation principle prototypes.

During the speech, Jiang Weiran also revealed that this year, Farasis Energy will supply batteries in bulk to leading global eVTOL customers.

Maximizing Performance: Farasis Energy Creates "6H Technology" Low-Altitude Power Batteries

"We now feel that the competition in the EV power battery sector is fierce, with numerous demands. However, in fields such as eVTOLs, not only are there numerous demands, but even more are required. It can be said that all key performances need to be maximized."Jiang Weiran stated that low-altitude batteries must meet higher requirements than EV batteries in terms of safety performance, energy density, cycle life, low-temperature performance, charging, high power, and flexible assembly. "It's not about achieving a certain threshold for a single indicator; rather, all indicators must meet very high requirements."

Taking the eVTOL battery with a mass-produced energy density of 350Wh/kg as an example, when enhancing energy density, it also achieves over 10,000 actual test cycles under eVTOL flight conditions, with excellent low-temperature performance and charge-discharge rates. It supports 8C continuous long-pulse discharge for 60 seconds at 30% SOC, and 15-minute rapid charging meets quick energy replenishment needs for passenger boarding and disembarking, enabling it to handle high-intensity eVTOL operating conditions and pass FAA aviation safety certification.

Based on a profound understanding of low-altitude power batteries and application scenarios, Farasis Energy has proposed a 6H low-altitude battery system characterized by "high safety, high energy density, high charge-discharge rate, wide temperature range operation, long cycle life, and high-quality standards":

High Safety: "When flying in the sky, batteries cannot have any accidents. There is zero tolerance for battery safety risks, so the requirements for battery safety, whether intrinsic or assembly safety, are extremely high." According to Jiang Weiran, Farasis Energy has designed a very strict product manufacturing process in terms of material system safety, battery cell intrinsic safety, assembly safety, and software control safety. Currently, the company's eVTOL batteries have met safety certifications in major international markets such as China, the US, and Europe, reaching international battery safety standards. After undergoing nail penetration tests, the battery cells show no significant changes in voltage and temperature, and there is no open flame after 24 hours. By adopting new-type phase change material technology, the surface temperature of thermally runaway battery cells can be continuously suppressed below 100°C for over 5 minutes. The BMS system adopts a dual-redundancy architecture design, ensuring the integrity of the discharge circuit and system-level safety and reliability even in the event of a single-point failure.

High Energy Density: Farasis Energy's second-generation eVTOL semi-solid battery cells are expected to enter small-batch production soon, with energy density increased to 320Wh/kg and long-pulse power reaching up to 10C. According to Jiang Weiran, eVTOLs equipped with Farasis Energy's second-generation batteries have a maximum takeoff weight of over 2.4 mt, a payload of nearly half a mt, and can carry 5 passengers.

In addition, the second-generation Plus version of eVTOL semi-solid battery cells is expected to enter mass production in 2026, with an energy density greater than 350 Wh/kg. Farasis Energy is systematically advancing the R&D of third-generation semi-solid and all-solid battery cells, targeting an energy density of 400Wh/kg, with various testing work progressing steadily.

High Charge-Discharge Rate: It possesses ultra-high-performance charge-discharge characteristics, fully adapting to the operational needs of eVTOLs under all conditions. At an ambient temperature of 25°C, it supports continuous discharge at a high C-rate of 8C, with a capacity retention rate >94% and a temperature rise of the battery cell <25°C. Charging from 10% SOC to 80% SOC takes less than 15 minutes, significantly reducing the recharging time. Its ultra-high power density meets the vertical takeoff and landing power requirements under extreme conditions such as emergency landings.

Wide Temperature Range Operation: It can operate stably and efficiently within a temperature range of -40°C to 60°C, with a capacity retention rate ≥90% at -20°C. It is fully compatible with complex operating conditions across multiple seasons, flight altitudes, and geographical (spatiotemporal) regions. With its rapid recharging capability, it can efficiently respond to sudden weather conditions, ensuring the safe takeoff and landing of aircraft.

Long Cycle Life: By constructing a highly stable pole piece structure, optimizing the kinetic balance design of the anode and cathode, and reserving sufficient expansion space for silicon particles, an ultra-long cycle life for the battery cell is achieved.

High-Quality Standards: Through PPM-level manufacturing quality control, comprehensive environmental factor control, and PPB-level process precision control, a PPB-level production system is established to ensure that the performance, safety, and lifespan indicators of battery products comprehensively meet industry benchmark levels.

Jiang Weiran pointed out that batteries for the low-altitude economy must achieve zero defects. This not only requires PPB-level production control but also stricter measures. For the eVTOL battery production line, Farasis Energy has implemented very stringent upgrades. Each production segment not only undergoes regular inspections but is also equipped with CT detection and full inspection of batteries before they leave the production line, ensuring that every battery cell is flawless.

Based on the 6H development, design, and manufacturing philosophy, Farasis Energy has not only gained recognition from leading domestic and overseas aircraft customers in the eVTOL battery field but also holds a leading advantage in various application scenarios for its low-altitude batteries, including logistics transportation, agricultural plant protection, surveying and mapping, and special purposes. According to Jiang Weiran, Farasis Energy's dedicated semi-solid battery cells developed for drones used in logistics transportation, agricultural plant protection, and other fields will also enter the stage of mass production, thereby taking the lead in forming a low-altitude power solution matrix covering multiple fields within the industry.

Pouch Battery: A Key Choice for Low-Altitude Power Applications

Low-altitude flight has high weight requirements. For batteries, the current R&D direction is to provide high energy while reducing their own weight.

Jiang Weiran pointed out that the lightweight advantage of pouch batteries is crucial for the low-altitude economy: "When providing the same amount of energy, the lighter design of pouch batteries can significantly improve overall energy efficiency. Based on the first principles of the low-altitude industry, we believe that pouch batteries are a key choice for low-altitude power battery applications."

In addition, looking at low-altitude flight designs both domestically and overseas, there are significant differences in models, sizes, and specifications. Pouch batteries offer excellent flexibility, adapting to different aircraft models and matching customers' varying power and voltage platforms.

It is understood that, in response to the internal design of eVTOLs, to further enhance adaptability, Farasis Energy has also planned and designed modules suitable for aircraft, compatible with the main cabin requirements of different aircraft, and capable of quickly meeting the needs of different customers for high-performance, high-safety aviation batteries.

From the perspective of battery technology iteration, semi-solid-state batteries and solid-state batteries are the future direction and the key batteries required for aviation aircraft such as eVTOLs. Judging from the current technological approaches of various companies, semi-solid-state and solid-state batteries mostly adopt the pouch form.

"Whether it's semi-solid-state, solid-state batteries, or aviation batteries, pouch batteries are the preferred choice," added Jiang Weiran. "Our overseas eVTOL customers conducted numerous tests when selecting batteries and ultimately chose Farasis Energy's pouch batteries. This decision was made by the company based on the first principles and a comprehensive consideration of various performance indicators required for eVTOLs."