Here is the English version of the article on the application of polyurethane foam in new energy vehicles, following the structure and content of the original Chinese text.

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Innovative Applications and Future Prospects of Polyurethane Foam Materials in New Energy Vehicles

I. Introduction

As the global automotive industry accelerates its transformation toward electrification, intelligence, and low-carbon development, the production and sales of new energy vehicles (NEVs) continue to rise, placing increasingly high demands on material performance. Among the many high-performance materials, polyurethane (PU) foam stands out as an indispensable key material for NEVs due to its lightweight nature, high elasticity, excellent sound and vibration damping properties, outstanding flame retardancy, and flexible designability. From thermal runaway protection in battery packs to lightweighting of vehicle bodies, from enhanced cabin comfort to chassis structural optimization, PU foam is playing an irreplaceable role in multiple application scenarios. This article systematically describes the core applications, technical progress, and development trends of PU foam materials in the NEV sector.

II. Overview of Polyurethane Foam Materials

Polyurethane foam is a high-molecular polymer produced by foaming isocyanates and polyols as main raw materials, together with blowing agents, catalysts, foam stabilizers, flame retardants, and other additives. Depending on physical form and performance characteristics, it is divided into flexible foam and rigid foam. Traditional PU foam, with its mature processes, stable performance, and high cost-effectiveness, has long occupied a dominant position in the automotive material market and is widely used in seats, headliners, instrument panels, carpets, and other interior components.

In the NEV sector, the application scenarios of PU foam have been further expanded and deepened. Its core value is reflected in the following aspects: lightweighting – reducing overall vehicle weight to increase driving range; safety protection – enhancing battery pack and vehicle safety through flame retardancy and energy absorption; NVH optimization – effectively reducing noise, vibration, and harshness to improve ride comfort; environmental sustainability – low-VOC, low-odor materials meeting increasingly stringent environmental regulations.

In terms of market size, the global automotive PU foam market maintains steady growth. According to QYResearch statistics and forecasts, global automotive PU foam sales reached USD 846 million in 2025 and are expected to reach USD 1.431 billion by 2032, with a compound annual growth rate of 7.8%. Seating systems account for approximately 40% of the market, instrument panels and center consoles for about 20%, door panel systems for about 15%, and interior and exterior trim for about 10%. The rapid adoption of NEVs and the trend toward automotive lightweighting are the main drivers of market growth.

III. Key Applications of Polyurethane Foam in NEV Battery Systems

The traction battery system is the core component of an NEV, and its safety and reliability directly affect vehicle market acceptance and user trust. PU foam plays multiple critical roles in battery packs, including potting protection, thermal management, lightweight structural components, and crash safety.

3.1 Flame-Retardant Potting and Thermal Runaway Protection

Battery thermal runaway is one of the biggest consumer concerns regarding electric vehicle safety. In response, significant breakthroughs have been achieved in PU potting foam technology. Covestro’s new Baysafe® BEF potting foam series combines excellent thermal insulation and flame retardancy: its lightweight foam effectively inhibits thermal propagation between cells and prevents fire spread, thereby significantly improving battery safety. This technology was launched just as China issued the mandatory national standard GB 38031—2025 “Safety Requirements for Traction Batteries of Electric Vehicles,” which for the first time requires that batteries shall not catch fire or explode after thermal runaway caused by internal short circuits. The new standard will take effect on July 1, 2026.

International material suppliers have also introduced targeted products. H.B. Fuller’s EV Protect 5006 is an ultra-lightweight two-component flame-retardant PU potting foam designed specifically for battery systems. It significantly reduces or delays thermal propagation during thermal runaway events, making it especially suitable for cell-to-pack applications. Its low-viscosity liquid flows easily and self-levels, curing into a semi-structural interconnected foam that encapsulates all components within the module. Additionally, Huntsman’s SHOKLESS™ FD lightweight foam technology can be used for potting and fixing cells in EV batteries, offering excellent compression and tensile properties, with high elongation at break helping to ensure reliable cell fixation.

3.2 Lightweight Structural Components for Battery Packs

For battery pack weight reduction, PU composites show significant advantages. Covestro’s Baypreg® STM uses a spray transfer molding process where PU resin is sprayed onto glass fiber mats and compression-molded into battery covers for EV high-voltage batteries. Compared with traditional steel housings, this solution achieves up to 60% weight reduction while providing excellent fire protection during thermal events. As a non-metallic material, the Baypreg® STM battery cover also offers natural corrosion resistance and electrical insulation, preventing arc discharge.

BASF and Beijing Weilan New Energy Technology jointly released a new-generation solid-state battery pack that also adopts a comprehensive PU material solution, including Elastoflex® PU STM battery top cover (up to 50% weight reduction), Elastan® low-density PU structural adhesive (optimizing structural integrity), and Elastolit® foam potting compound with Elastocoat® fire protection coating (enhancing thermal runaway resistance). These materials work synergistically to fully protect against thermal runaway, mechanical shock, overcharging, and short circuits, meeting national standard GB 38031 and global battery standards.

3.3 Battery Crash Safety Protection

High-voltage batteries face significant risks in accidents, as excessive mechanical force may damage cells and trigger thermal runaway. Covestro’s Baysafe® EA (energy absorption) PU molded foam is specially developed for crash safety components in vehicles. Its optimized foam structure uses low densities of only 40–80 kg/m³, effectively limiting mechanical loads transmitted to the cells and keeping the maximum cell compression below 60%. The crash protection performance has low temperature dependence. The honeycomb structure of this foam can also be used for thermal isolation between cells and the ambient environment, further improving battery thermal management efficiency.

3.4 Thermal Conductivity and Structural Bonding

As requirements for potting adhesives in NEV three-electric systems (battery, motor, electronic control) continue to increase, the synergistic optimization of thermal conductivity and structural bonding has become an important direction. CollTech’s PU thermal conductive structural adhesive N-PU 5812LE features a high thermal conductivity coefficient, quickly dissipating heat generated during cell operation while providing strong interfacial bonding. Through the synergistic optimization of “thermal conduction + bonding,” it addresses the dual challenges of “heat dissipation” and “structural fixation” in battery systems. Gaoxin New Materials has also applied for a patent on PU thermal conductive adhesive, using polycarbonate polyols copolymerized from CO₂ and propylene oxide as well as bio-based polyols. This approach improves the carbon source ratio while meeting performance requirements, facilitating battery disassembly and recycling.

IV. Applications of Polyurethane Foam in Body Structure and Lightweighting

4.1 High-Strength Lightweight Composites

The application of PU composites in NEV body structural components is expanding. The Baypreg® series of PU composites are produced by spraying PU onto glass fiber mats and compression molding. The process is highly efficient, low-emission, and has short cycle times, producing lightweight products with high mechanical strength. When combined with natural fiber or carbon fiber mats, economical and more sustainable processes can produce thin-walled interior parts and lightweight lining components, as well as lightweight sandwich structures with good flexural and torsional rigidity. Composites made from PU resin and glass fibers via pultrusion can achieve 25–30% weight reduction compared with conventional metal structures, significantly improving vehicle performance.

4.2 Cavity Filling and NVH Optimization

PU foam offers unique advantages in body cavity sealing. Compared with the more commonly used two-shot injection-molded expansion baffles, PU foam not only provides reliable three-dimensional expansion and sealing but also possesses excellent sound absorption characteristics that conventional baffles lack, showing outstanding performance in suppressing airborne noise transmission. BASF’s Elastoflex® W flexible foam is used to absorb airborne noise, while viscoelastic foam absorbs structure-borne noise; both can be used under carpets, on engine hoods, and in instrument panel encapsulation layers. Huntsman’s ACOUSTIFLEX® series of PU foam products can produce high-resilience, slow-recovery, and comfort-touch foams for vehicle flooring and sound insulation, effectively reducing noise from the engine and road.

V. Applications of Polyurethane Foam in NEV Interiors and Comfort

5.1 Seat and Cabin Comfort

Flexible PU foam is most widely used in NEV interiors, mainly for seats, headrests, armrests, and headliners. It not only provides a comfortable riding experience but also absorbs noise and reduces impact, improving safety. High-resilience PU foam is commonly used in vehicle seats, furniture cushioning, and various laminated composites. Its low density, breathability, sound absorption, thermal insulation, and good resilience make it an ideal choice for enhancing cabin comfort. Covestro’s Bayfill® semi-rigid PU filling foam is often used for instrument panel padding and interior trim, producing components with a pleasant feel, noise reduction properties, and very low volatile emissions.

5.2 Steering Wheels, Instrument Panels, and Door Panels

PU materials are also widely used in steering wheels, instrument panels, and door panels. Huntsman’s RUBITRIM® steering wheel PU uses a fully water-blown microcellular foam system, simplifying the process while providing appropriate cycle times, durable performance, and a comfortable tactile feel, meeting manufacturers’ low-VOC and low-odor requirements. For instrument panels, RUBITRIM® technology can be used together with in-mold painting to provide excellent elasticity and a “soft-touch” feel. Door panels similarly use this technology to achieve the desired tactile feel and appearance. PU headliners use semi-rigid foam made with ACOUSTIFLEX® technology to effectively reduce road noise.

5.3 Low-VOC and Eco-Friendly Materials

To improve in-vehicle air quality and reduce interior noise, the industry’s demand for low-VOC, low-odor materials is growing rapidly. Jiahua Chemical’s PU product series provides NEV manufacturers with low-VOC, low-odor raw materials, enabling noise reduction, vibration damping, and sound absorption, thus offering excellent NVH solutions for vehicles. Wanhua Chemical’s fully water-blown flexible PU foam uses 100% water as the blowing agent, contains no fluorine compounds, and has excellent flame retardancy, with total VOC far below national standard requirements. BASF used sustainable materials such as bio-based and Ccycled® PU (Elastoflex®) and foamed thermoplastic polyurethane Infinergy® in the Kia EV3 Study Car concept, helping to reduce overall carbon emissions.

VI. Environmental Regulations and Sustainable Development

With growing environmental awareness and increasingly stringent regulations, PU foam materials face higher requirements for environmental compliance. Under the REACH regulation, several isocyanates including toluene-2,4-diisocyanate (TDI), hexamethylene diisocyanate (HDI), and diphenylmethane-4,4‘-diisocyanate (MDI) are listed in Annex XVII restricted substances, posing challenges for the compliance management of automotive PU materials.

At the same time, the industry is accelerating its green transformation. Environmentally friendly blowing agents are being widely adopted; solvent-free and waterborne PU synthetic leather technologies have achieved large-scale industrialization; and low-odor, low-VOC product technologies have been successfully promoted. The development and application of green and low-carbon raw materials such as bio-based polyols and CO₂-based polyols are accelerating. Products such as Covestro’s Baysafe® BEF and Huntsman’s SHOKLESS™ FD are available in versions with recyclable content based on mass balance methods, supporting customers’ carbon reduction goals.

VII. Market Outlook and Technology Trends

Looking ahead, the development trends in the automotive PU foam industry will focus on innovations in lightweight, environmentally friendly, and high-performance materials, as well as advances in intelligent manufacturing and multifunctional integration. As the demand for automotive lightweighting continues to rise, the need for lightweight yet high-performance PU foam materials will maintain strong growth. Stricter environmental regulations will push the industry to accelerate the transition to bio-based and recyclable materials.

At the technical level, the following directions deserve special attention: balancing high thermal conductivity and lightweighting – by 2026, requirements for potting adhesives in NEV three-electric systems will further increase, and multifunctional potting adhesives with thermal conductivity ≥3 W/m·K, density <2 g/cm³, flame retardancy, and low volatile characteristics will become preferred choices; deep integration of intelligent manufacturing – accelerated construction of automated production lines and smart warehouse logistics systems, along with exploration of AI-assisted new material R&D, will inject new vitality into industry innovation; circular economy and low-carbon development – transitioning from traditional fossil-based raw materials to bio-based and CO₂-based polyols to achieve full-lifecycle decarbonization has become an important development direction for the industry.

VIII. Conclusion

Polyurethane foam materials, with their excellent properties of lightweight, flame retardancy, sound absorption, and shock absorption, demonstrate broad application prospects in the field of new energy vehicles. From safety protection of traction batteries to vehicle lightweighting and NVH optimization, from cabin comfort enhancement to chassis structural reinforcement, PU foam technology is deeply integrating into every key aspect of NEVs. With continued innovation in materials science, production processes, and environmental technologies, as well as the vigorous development of the global NEV industry, PU foam materials will undoubtedly play an even more important role in the new journey toward green mobility, providing solid material support for building a safe, comfortable, and low-carbon future transportation system.

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