Photo credit: Visual China

Blue Whale News, August 7 (Reporter Li Zhuoling) More and more battery companies are extending their reach into the low-altitude economy sector.

Recently, Fengfei Aviation officially announced the signing of a strategic investment and cooperation agreement with CATL, and the two companies will jointly focus on the research and development of eVTOL aviation batteries. Behind CATL, other battery companies such as Farasis Energy, EVE Energy, Guoxuan High-tech, Lishen Battery, and Sunwoda have also entered the market in advance to secure a foothold.

Under this trend, the current 'battery war' has gradually spread from the electric vehicle sector to the low-altitude sector. As the 'heart' of an electric vehicle, batteries account for up to 40% or more of the total vehicle cost. So, what role do they play in eVTOL (Electric Vertical Take-Off and Landing aircraft)? What are the reasons behind battery companies rushing into the low-altitude economy sector?

Batteries account for more than 15% of the cost of eVTOLs

According to incomplete statistics, more than 10 battery companies are currently deploying in the aviation electric field, with most choosing to jointly develop with eVTOL companies.

Before partnering with Fengfei Aviation, CATL's Chairman Zeng Yuqun stated at the BEYOND International Technology Innovation Expo held in May this year that CATL was collaborating on the development of electric aircraft batteries. "We need to start with small aircraft and gradually scale up to 8.8-ton aircraft," he said. In June this year, he revealed that CATL had successfully flight-tested a 4-ton civilian electric aircraft.

It is understood that the weight of most domestic eVTOL aircraft currently ranges from 600 kg to 2 tons. For reference, Fengfei Aviation's self-developed 'V2000CG Carrion Gull' is a 2-ton eVTOL aircraft, while EHang's EH216-S has a maximum takeoff weight of 620 kg.

In addition to CATL, EVE Energy disclosed on its investor interaction platform at the end of May this year that the company had an early layout in the eVTOL battery field and had already collaborated with a foreign company on research for three years. It has delivered A-sample products and is assisting clients in obtaining relevant aviation system certifications. Furthermore, the company has also sent samples to other international clients.

In April this year, Farasis Energy also revealed on its interaction platform that the company had collaborated and supplied batteries to overseas and domestic clients in the manned aircraft sector and was actively communicating with several domestic potential clients to jointly promote the development of the low-altitude flight sector. Its Chairman Wang Yu stated last year that Farasis Energy had ventured into the exploration of aerial electrification five or six years ago.

EHang partnered with Guoxuan High-tech in December last year to jointly develop power cells, battery packs, charging infrastructure, etc., for its unmanned eVTOL products. Then, in April this year, it partnered with JW AutoTech to jointly develop ultra-fast/extremely fast charging battery solutions for eVTOL aircraft.

Behind the collaboration between battery companies and eVTOL companies to drive battery research and development lies a multi-billion-yuan market opportunity.

Data released by the Civil Aviation Administration of China shows that the low-altitude economy market will reach a size of 1.5 trillion yuan by 2025. According to industry insiders, the battery segment is expected to account for 15%-20% of this market, translating to an incremental market of over 200 billion yuan for the battery industry.

Similar to the importance of batteries to electric vehicles, the power system plays the role of the 'heart' in a pure electric eVTOL. In terms of cost, multiple industry insiders from leading eVTOL companies have revealed that it is quite high.

"The cost of the power system (including batteries, motors, electric controllers, propellers, power control systems, etc.) accounts for about 40% of the total cost," Shen Haijun, Director of the Institute of Flight Vehicle Engineering at Tongji University, told Blue Whale News.

The head of XPeng HT Aero's power systems department told Blue Whale News that compared to electric vehicles, the overall cost of eVTOLs is higher due to the need to consider aviation airworthiness requirements and high-strength lightweight design for components other than power batteries. Therefore, the cost proportion of power batteries will decrease accordingly. "Based on currently available information on various eVTOL models domestically and internationally, it is estimated that power batteries account for about 15%~25% of the total cost of eVTOLs, lower than the approximately 40% proportion in electric vehicles," he said.

Research and Development Directions: High Performance + High Safety

Currently, the research and development of pure electric eVTOL batteries focuses on enhancing energy density and performance. Compared to electric vehicles, eVTOLs have stricter requirements for the performance of the power batteries they carry.

"The energy density of eVTOL batteries is a crucial indicator," Shen Haijun told Blue Whale News. High energy density means lighter weight, abundant energy, and longer range.

The aforementioned head of XPeng HT Aero's power systems department also told Blue Whale News that since eVTOL flight missions encompass both vertical take-off and landing conditions and cruising conditions, and the power requirements for these conditions are typically 5~10 times that of pure electric vehicles, the design of power batteries must pursue high energy density while also aiming for high discharge rates to meet these power demands and ensure endurance. Additionally, to enable rapid energy replenishment, the charging rate of the batteries must also be considered.

According to him, there are currently two ways to increase the endurance of pure electric eVTOLs: by increasing battery capacity or by optimizing the overall aerodynamic efficiency of the aircraft to reduce battery discharge rates.

"To ensure high battery safety while enhancing energy density and charge/discharge capabilities, we need more innovations in cell material systems, housing structures, and materials. Additionally, extensive integration and lightweight design of the entire battery pack are necessary to minimize its weight contribution to the overall aircraft (below 35%)."

According to the "Green Aviation Manufacturing Development Plan (2023-2035)" issued by the Ministry of Industry and Information Technology and three other departments, in terms of the engineering development of electric general aviation aircraft, it is required that 400Wh/kg-level aviation lithium-ion battery products that meet the usage and airworthiness requirements of electric aircraft be put into mass production, with 500Wh/kg-level products undergoing small-scale verification.

Under the cooperation between Fengfei Aviation and CATL, the two parties will focus on enhancing the energy density and performance of eVTOL batteries, supporting longer flight distances and higher payloads for eVTOLs, while also achieving more significant improvements in safety and stability.

At the same time, CATL has previously promoted the collaborative development of solid-state batteries for civilian electric manned aircraft projects. The company's Chief Scientist Wu Kai revealed in April that this year, CATL's solid-state batteries have successfully completed their maiden flight on a validation aircraft weighing over one ton.

According to data released by CATL last year, its solid-state battery cells have an energy density of 500Wh/kg. Prior to this, in response to investor inquiries, CATL stated that according to the company's 2022 annual report, its ternary lithium-ion battery cell had a mass energy density of 220-300Wh/kg for battery electric vehicles (BEVs).

In Shen Haijun's view, research directions such as solid-state batteries and hydrogen energy power systems are worth paying attention to. "Solid-state batteries are the trend, and hydrogen fuel cells and sodium-ion batteries are also expected to further develop and participate in the competition with traditional lithium-ion batteries," he said.

Taking solid-state batteries as an example, Sunwoda revealed on its investor platform in June this year that its solid-state battery company has been involved in research and development since 2015, with plans for first-generation 400Wh/kg and second-generation 500Wh/kg solid-state batteries. The latest ampere-hour-level sample of the first-generation solid-state battery can achieve stable cycling for more than 1,000 cycles, while the second-generation laboratory sample has achieved an energy density target of 500Wh/kg.

"Energy density is an important indicator, but we cannot ignore the lifespan and safety of the product," the company added.

"In addition to high performance, the development of lithium batteries for eVTOLs must also prioritize high safety," the head of XPeng HT Aero's power systems department pointed out. The design of power batteries for eVTOLs will be more oriented towards aviation safety requirements, especially for the battery's crashworthiness and tolerance after thermal runaway, which will be significantly higher than national automotive standards.

Another executive from a leading eVTOL company similarly told Blue Whale News that aircraft weight reduction is one of the safety indicators, and it's not always better to have more batteries or longer range. In their view, in addition to range, innovations in energy replenishment methods such as fast charging and battery swapping can also improve operational efficiency in the future, which is a promising direction to explore.