Researchers in China have developed a thin ceramifiable silicone foam composite that they say can prevent thermal runaway propagation in lithium-ion battery modules by forming a protective ceramic barrier under extreme conditions.
The work, published in Nano-Micro Letters, was carried out by scientists from China University of Petroleum-Beijing and the China Academy of Safety Science and Technology, led by professors Congling Shi and Laibin Zhang.
The researchers said the material addresses a longstanding compromise between thermal insulation and mechanical durability. Conventional organic foams can provide low thermal conductivity but degrade above 300°C, while inorganic materials withstand heat but are vulnerable to the high-pressure gas jets generated during thermal runaway events.
Silicone foam matrix becomes ceramifiable during exposure to high temperatures
The new material combines a polydimethylsiloxane (PDMS) silicone foam matrix with glass fibre fabric and a range of functional fillers including ammonium polyphosphate, zinc borate, kaolin and silica aerogel. During exposure to high temperatures, the additives promote the formation of a dense ceramic layer that acts as both a thermal and mechanical barrier.
According to the researchers, the composite maintained stable elasticity from –40°C to 300°C and retained 93% of its stress after 1,000 compression cycles. Thermal conductivity was reduced to 0.046W/m·K, while total heat release and smoke generation were lowered by 54.4% and 87.9%, respectively. The material also achieved a UL-94 V-0 flammability rating.
In tests using commercial 37Ah prismatic lithium-ion cells, a 3mm layer of the material prevented thermal runaway from spreading beyond the initiating cell. By contrast, unprotected modules experienced full thermal runaway propagation within seconds, while modules using conventional silicone foam only delayed the process.
The authors said the composite’s ability to conform closely to aluminium cell casings helps minimise thermal contact resistance, and noted that the manufacturing process is compatible with industrial roll-to-roll production.
They believe the technology could provide a practical route to improving the intrinsic safety of battery energy storage systems and next-generation energy storage installations.
The paper, entitled Constructing Intrinsically Safe Lithium-Ion Battery Energy Storage via Gradient-Laminated Ceramifiable Silicone Foams, was published on 21 May 2026.
Illustration: A gradient laminated architecture is engineered to resolve the intrinsic trade-off between thermal insulation and impact toughness via synergistic ceramisation. The composite exhibits exceptional fatigue resistance with 93% stress retention and stable elasticity across a wide temperature range (from -40 to 300°C). The formed dense ceramic barrier effectively intercepts high-pressure gas jets, confining thermal runaway to a single cell in battery modules.
Credit: Shuilai Qiu, Jingyao Xu, Congling Shi, Laibin Zhang.
