A single lithium-ion battery cell in thermal runaway can spike past 1,000 degrees Celsius in seconds. In a tightly packed EV battery module, that heat jumps to neighboring cells almost instantly, turning one failing cell into a full-pack fire. Researchers at Nanjing Tech University in Nanjing, China, say they have built a material thin enough to slip between those cells and tough enough to block the heat: a silica aerogel sheet rated to withstand temperatures approaching 1,300°C (2,372°F).
The team, led by materials scientist Xiaodong Shen, calls the aerogel a “firewall” for power batteries. Their goal is deceptively simple: keep a single cell’s failure from becoming a catastrophe. And the urgency behind that goal is now backed by hard numbers. A peer-reviewed dataset published in Joule (Cell Press) documented 417 real-world EV fire incidents between 2022 and mid-2025, concluding that existing battery safety regulations, including China’s GB 38031-2020 standard, do not adequately prevent fire propagation between cells.
How the aerogel works
The concept is straightforward. Thin silica aerogel sheets are placed in the narrow gaps between grouped battery cells inside a module. Aerogels are among the lightest solid materials ever created, mostly air by volume, yet they are exceptionally poor conductors of heat. When one cell overheats and enters thermal runaway, the aerogel acts as a heat shield, slowing or blocking the transfer of extreme temperatures to adjacent cells. That delay, even if measured in minutes rather than hours, can be the difference between a contained failure and a vehicle fire.
An earlier version of the material was tested at 1,200°C, with results published in a peer-reviewed Materials Letters study that included detailed time-at-temperature degradation data. The university described the aerogel as building a “safety insulating suit” for power batteries. An upgraded version, referenced in a separate university announcement carried by Xinhua Daily, pushes the rated temperature to just under 1,300°C, placing it squarely in the range generated during severe thermal runaway events.
Nanjing Tech has also disclosed a patent partial-rights transfer for a related phase-change flame-retardant fiber material designed for lithium-ion battery thermal management in enclosed spaces. According to the university’s tech-transfer office, that fiber reduces battery surface temperatures by roughly 20°C and demonstrates measurable flame-exposure resistance. It is worth noting that the patent transfer claim is sourced solely to the university’s own tech-transfer office and has not been independently verified by a third party.
Why the problem is getting harder to ignore
The 417-incident Joule study, published in early 2026, is one of the most comprehensive public analyses of EV fire behavior to date. Its authors examined how fires propagate through battery packs and identified specific regulatory gaps that allow dangerous heat transfer between cells. The study’s critique of GB 38031-2020 is pointed: the standard was designed around single-cell abuse tests and does not fully account for the cascading, multi-cell failures that drive real-world fires.
That finding matters because battery energy densities keep climbing. Automakers and cell manufacturers are packing more capacity into the same physical volume, which means cells sit closer together and generate more heat per unit of space. Major players like CATL and BYD already use various thermal barrier materials, including some aerogel-based solutions, in certain battery pack designs. But the Joule data suggests current approaches still leave gaps, particularly in worst-case scenarios where multiple cells fail in rapid succession.
Separately, researchers at the University of Science and Technology of China have published work on insulation materials engineered to halt thermal runaway propagation at the module level, with tests comparing outcomes with and without barriers. Their results reinforce the same conclusion Nanjing Tech’s team is working from: physical insulation between cells is one of the most direct ways to slow fire spread.
What still needs proving
The jump from 1,200°C to 1,300°C has not yet received the same level of independent peer-reviewed validation. The 1,200°C figure is backed by a published Materials Letters study with named co-authors and specific degradation metrics. The 1,300°C figure, as of May 2026, originates from institutional announcements reposted by Nanjing Tech from Chinese state media outlets. No peer-reviewed paper in the available evidence base validates the upgraded claim with independent test protocols or third-party replication.
Durability under real driving conditions is another open question. Laboratory tests at constant high temperature do not replicate the vibration, impacts, and long-term aging that materials endure over years of road use. Without published cycling and mechanical-stress data, it is difficult to predict how the aerogel will perform across the full lifetime of an EV battery pack, typically eight to fifteen years.
Cost remains undisclosed. The university has confirmed scale-up and production activity, and the patent transfer signals commercial intent, but no public statement specifies a per-unit price for the aerogel sheets, a target date for integration into mass-produced packs, or which automakers have committed to adoption. For an industry where battery cost per kilowatt-hour is tracked to the dollar, that gap matters. Manufacturers operating on thin margins may not voluntarily add new materials unless regulators or insurers reward improved fire performance.
On the regulatory front, the Joule study explicitly calls out limitations in GB 38031-2020. China has moved to update that standard, with a GB 38031-2025 draft circulated in 2025 that proposes stricter thermal propagation requirements. However, no available evidence as of May 2026 indicates whether the finalized revision will specifically require or incentivize aerogel-type barriers. Without such a mandate, adoption depends on voluntary action, a slower and less predictable path.
Where this fits in the broader EV fire-prevention race
No single material will eliminate EV battery fires. The most effective safety strategies layer multiple defenses: advanced battery management software that detects early warning signs, module-level venting systems that direct gases away from passengers, fire-suppression systems, and physical barriers like the Nanjing Tech aerogel. How these systems interact with each other in a real vehicle, under real failure conditions, is still an area that needs structured testing.
What the available evidence does support is that better thermal barriers between cells can meaningfully slow or stop fire spread. The peer-reviewed data at 1,200°C is solid. The 417-incident fire dataset provides a concrete, recent foundation for understanding why current protections fall short. And the institutional signals from Nanjing Tech, including patent activity and scale-up announcements, suggest the research is moving toward commercial reality.
Whether this specific aerogel becomes an industry standard will depend on cost, manufacturability, regulatory decisions, and independent testing that has not yet been published. For now, the material represents one of the more promising entries in a race that EV adoption has made unavoidable: engineering battery packs that fail gracefully, one cell at a time, instead of all at once.
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*This article was researched with the help of AI, with human editors creating the final content.
