Interview with Sunwoda: Accelerating the Industrialization of eVTOLs, How "Forward Development" Tackles Battery Pain Poi

China's low-altitude economy is entering a critical period of synchronized technological upgrades and commercial implementation. On one hand, the development of low-altitude aircraft, with eVTOLs (electric vertical take-off and landing vehicles) at the core, has advanced significantly toward the pivotal stage of airworthiness certification. A clear signal is that TC (Type Certificate) applications from numerous companies, including AutoFlight, Xpeng AeroHT, and Woofly, have been accepted. The industry anticipates that a密集 issuance of TCs will begin in 2026.

Meanwhile, practical applications of eVTOLs are flourishing across multiple fronts: cargo eVTOLs have taken the lead in commercialization, passenger eVTOLs are steadily progressing with demonstration flights in specific scenarios like cultural tourism, and amphibious flying cars are exploring their unique value in specialized environments. These low-altitude aircraft, targeting the 50–400 km short-to-medium-haul travel market, are following an increasingly clear development path: from cargo to passenger transport, from meeting specialized needs to integrating into daily life, and from public service applications to full-scale commercial operations.

At this juncture, Xu Zhongling, Dean of Sunwoda Central Research Institute, sat down for an in-depth interview with Gaogong Lithium. He emphasized that the high-dimensional demands of the low-altitude economy on power batteries are not limited to breakthroughs in a single performance metric but rather pose a comprehensive challenge balancing energy density, power density, and safety. Aviation-grade safety standards, in particular, far exceed those for passenger vehicles, presenting unique challenges and value propositions for electric aviation batteries. This requires battery manufacturers not only to accelerate R&D in high-energy-density, high-power, and high-safety technologies but also to develop technical solutions tailored to diverse niche scenarios, thereby raising the bar for their technological planning capabilities.

To address these challenges, leading domestic battery companies are actively expanding their portfolios. Sunwoda has launched a range of specialized battery products for electric aviation, including:

• A 320 Wh/kg eVTOL-specific battery (already in mass production).

• A 360 Wh/kg high-specific-energy pouch semi-solid-state cell.

• A 46-series large cylindrical battery exceeding 350 Wh/kg.

• A 230 Wh/kg high-power pouch cell for hybrid-electric applications.

Guided by the philosophy of "forward development," Sunwoda is spearheading technological innovation across materials, cells, and systems to tackle industry pain points and drive the overall advancement of battery technology.

Aviation Power Batteries: Extreme Performance, Balanced Requirements, and Uncompromising Safety
Compared to automotive applications, electric aviation imposes far stricter demands on power batteries. Xu Zhongling notes that these demands are not confined to single performance metrics but present a high-stakes challenge requiring a balance of energy density, power characteristics, and safety.

• Energy density is critical for determining an aircraft’s range and payload. Calculations show that increasing the specific energy of a battery system from 200 Wh/kg to 500 Wh/kg could boost an eVTOL’s effective payload by nearly 25% or extend its cruising range by almost twofold.

• High-rate discharge capability is equally vital. During vertical take-off and landing, batteries must deliver 3–8C high-power output within 30 seconds to 1 minute. Even at a low 20% state of charge (SOC) during landing, the same power demand must be met.

• Safety is the lifeline of electric aviation batteries. High-altitude cruising, low-pressure environments, high energy density, and high-rate discharge collectively create severe safety challenges. Xu stresses that aviation-grade safety standards far surpass those for passenger cars. For instance, in the event of any battery system failure—even if the aircraft is damaged—the remaining battery capacity must ensure a safe landing. This means that even if half the batteries fail, the rest must support the aircraft’s safe descent. Additionally, batteries must pass tests such as high-altitude drop without ignition, and for passenger aircraft, toxic gases from thermal runaway must not enter the cabin—requirements that go beyond automotive standards, which only mandate escape time for occupants.

Sunwoda’s "Forward Development": Dual-Technology Path Strategy
To meet the stringent demands of electric aviation batteries, Xu Zhongling explains that Sunwoda is adopting a "forward development" strategy, "seeking certainty amid uncertainty" by pursuing two parallel technology paths: large cylindrical and pouch solid-state batteries.

• Large cylindrical batteries offer advantages for eVTOLs, such as energy density upgrades based on existing material systems and high safety. Their compatibility and standardization facilitate platform-based development and mass production, making them suitable for aircraft with larger power demands. However, their system integration efficiency is relatively low, and they may struggle to meet highly customized requirements.

• Pouch cells, on the other hand, excel in unlocking the energy density potential of battery chemistries, particularly accommodating silicon anode expansion issues, leaving room for further improvements in energy density and lifespan. With inherently safer chemistries—especially semi-solid and solid-state technologies—the safety drawbacks of pouch cells at the cell level can be mitigated. Moreover, pouch cells’ adaptability allows for customized dimensions and capacities, maximizing space utilization in eVTOL designs.

This dual-path approach reflects Sunwoda’s comprehensive trade-offs in platformization, cost, safety, future technology adaptability, customization, and space efficiency.

Currently, Sunwoda has achieved milestones in electric aviation batteries:

• Its mass-produced eVTOL-specific battery, "Xin·Yunxiao 1.0," delivers 320 Wh/kg energy density, 3300 W/kg continuous power density at room temperature, operates across -30°C to 60°C, supports 2000 cycles, and has passed extreme-environment airworthiness tests.

• The upgraded "Xin·Yunxiao 2.0" boasts 360 Wh/kg energy density, 3900 W/kg power density, 10C continuous discharge, -35°C to 80°C operating range, 1800 cycles, and system-level thermal runaway prevention, passing over a dozen rigorous safety tests including 200°C hotbox and nail penetration.

• For large cylindrical batteries, Sunwoda’s 46-series cells feature bidirectional full-tab structures, high-nickel high-silicon chemistry, and high-strength casings. The second-generation products achieve ≥350 Wh/kg energy density, ≥3C fast charging, ≥10C high-rate discharge under extreme conditions, and ≥1000 cycles.

These high-specific-energy solutions cater to pure-electric eVTOLs’ needs for higher payloads and longer ranges, suitable for both passenger and cargo aircraft. For hybrid-electric aircraft requiring power supplementation during take-off and landing, Sunwoda has developed a 230 Wh/kg pouch cell with 20C continuous discharge and 70C instantaneous discharge capabilities.

Sunwoda’s differentiated edge in electric aviation batteries lies in its ability to meet diverse application needs while surpassing the industry’s 300 Wh/kg energy density benchmark. By offering faster charging and longer cycle life, it helps OEMs reduce operational costs and enhance profitability.

Technological Core: Systemic Innovation Addressing eVTOL Battery Pain Points
Underpinning these advantages is Sunwoda’s systemic innovation in electric aviation battery technology. Xu Zhongling highlights that eVTOL battery R&D pain points first manifest at the material level, centering on how to ensure high safety and long cycle life while pursuing high-specific-energy active materials. Sunwoda has tackled this through systematic breakthroughs:

• For high-nickel ternary cathodes, precise coating and doping technologies achieve 230 mAh/g specific capacity while raising the DSC exothermic onset temperature by 20°C, enhancing intrinsic safety and thermal stability.

• For anodes, alloy-designed silicon-carbon materials deliver 2700 mAh/g specific capacity and double cycle life. Combined with upgraded electrode technology, they achieve near-zero expansion at 100% depth of discharge (DOD), reducing electrode elongation by 90% and mitigating silicon anode expansion.

• Custom electrolytes withstand high voltage and the strong oxidation of high-nickel cathodes while enabling high ionic conductivity for high-power discharge and meeting aviation flame-retardancy standards.

• Innovative double-sided coating and zero-thermal-shrinkage separator enhancements further improve reliability and safety under extreme conditions.

Another major R&D challenge lies in electrodes: achieving high-power continuous discharge without compromising energy density or safety. Sunwoda’s "soft solid-state" battery technology merges the high safety of solid-state systems with the high power of liquid systems, striking an optimal balance for aviation power batteries.

Xu notes that eVTOLs’ extreme performance demands and relatively lenient cost environments allow technologies previously shelved in automotive batteries due to cost constraints to find their first applications in eVTOL batteries.

For safety, since liquid cooling adds significant weight, electric aviation batteries typically adopt air or forced-air cooling, demanding superior heat dissipation and temperature uniformity. Sunwoda has developed cost-effective, efficient thermal management solutions and multi-level thermal protection with smart early-warning technologies from cells to packs.

Aviation Battery R&D Driving Industry Advancement
Battery manufacturers’ "forward development" practices are shaping eVTOL battery evolution, with solid-state batteries emerging as a key battleground. Sunwoda views low-altitude economy battery R&D as an innovation engine for upgrading the entire battery technology ecosystem, not just a solution for new applications. Xu emphasizes that breakthroughs here, especially in solid-state batteries, will feedback into and accelerate advancements in new energy vehicle batteries, revealing the strategic synergy behind Sunwoda’s low-altitude economy focus.

Currently, the low-altitude economy is transitioning from policy-driven beginnings to a phase marked by R&D成果落地 and批量 market orders. By the end of 2024, leading eVTOL makers like Xpeng AeroHT and Eve Air Mobility had orders exceeding 3000 units each, with EHang surpassing 1500. By April 2025, multiple OEMs had partnered with financial leasing firms and banks, securing 470意向 orders. Electrification remains the key trend sustaining eVTOLs’ long-term competitiveness.

Market projections estimate China’s cumulative eVTOL demand will surpass 16,000 units by 2030. Assuming 200 kWh per aircraft and aviation-grade battery prices at ¥3/Wh, the front-load market could approach ¥10 billion. Order commitments and deepening产融协同 are solidifying growth certainty in this emerging sector.

Sunwoda has established deep partnerships with leading global eVTOL companies, showcasing its technology-driven positioning. Looking ahead, it plans to launch aviation power batteries exceeding 400 Wh/kg. Its all-solid-state electrolyte prototype—60Ah, 1500 cycles, -30°C to 80°C operation, 400 Wh/kg—has passed nail penetration and 200°C hotbox tests. Xu predicts that achieving such energy density without sacrificing safety or power performance will usher in a golden age for low-altitude aircraft batteries.

On mass production challenges, Xu notes that liquid or semi-solid-state processes differ little from existing power batteries, requiring tighter humidity control and ppb-level defect detection. All-solid-state batteries present more unique hurdles. Platformization and standardization will be critical for cost reduction and sustainable industry growth.

In summary, from collaborative supply chain development to mass production, the eVTOL battery industry is establishing measurable, traceable standards and协同 processes. The low-altitude economy’s rapid ascent is stretching the boundaries of power battery technology, propelling the entire industry to new heights.

With its deep technical积累, "forward development" ethos, and dual-technology roadmap, Sunwoda is seizing the historic opportunities presented by eVTOL industrialization, aiming to lead technologically and commercially in the vast blue ocean of the low-altitude economy.