Polyurethane Vehicle Battery Cover Slashes Weight

As the popularity of new energy vehicles (NEVs) grows, so does the demand for lighter-weight and higher-performing materials, as well as more efficient production of essential components, such as battery packs. To meet this need, Covestro has collaborated with a Chinese partner to develop the Baypreg STM polyurethane (PU) battery cover solution, which will be showcased at the China Composites Expo (CCE), Asia’s largest exhibition for composite materials, from Sept. 2 to 4 in Shanghai. Under the theme “Empower Your Composite Solutions,” Covestro’s booth will also feature PU composite innovations applicable in photovoltaics and energy storage, construction, and infrastructure.

By means of the spray transfer molding process, PU resins are sprayed onto glass fibers and molded into battery covers. Image courtesy of Covestro.

Baypreg STM employs the spray transfer molding process, where PU resins are sprayed onto glass fibers and molded into battery covers, enabling efficient production of composite components. Developed in collaboration with Liyang Shanhu Industrial, a Tier 1 supplier of automotive parts and battery packs to Chinese and international OEMs, this solution represents a significant technological advance that is also cost-effective.

Lighter, high-performance battery covers

This PU solution reduces battery cover weight by more than half compared to traditional steel solutions. As a non-metallic material, the Baypreg battery cover inherently offers superior anti-corrosion and insulation properties, effectively preventing electric arcing. When compared with non-metallic options, it outperforms in terms of surface smoothness and airtightness. It also demonstrates high strength, meeting tough requirements from OEMs.

“As the inventor of polyurethanes, Covestro brings decades of expertise in the automotive industry, with PU solutions enhancing both driving and riding experiences in automotive interiors and exteriors. We can now extend this expertise to NEVs, as well,” said Akhil Singhania, global head of PU Specialties at Tailored Urethanes, Covestro. “The Baypreg STM solution showcases Covestro’s ability to deeply understand evolving market needs and rapidly innovate cutting-edge material solutions. Our goal is to deliver lighter, more efficient, and sustainable solutions through continuous technological innovation.”

The NEV industry has witnessed rapid growth in recent years. According to the China Passenger Car Association, NEV sales accounted for 51% of total passenger car deliveries in China in July 2024, exceeding the sale of internal combustion engine vehicles for the first time. 

Diverse applications for PU composites

At the CCE, Covestro will also showcase its PU composite solutions across various sectors. For instance, PU composites are widely utilized in photovoltaic (PV) modules to enhance efficiency and quality. Specifically, PU frames combined with coatings from Covestro offer superior corrosion and weather resistance for PV modules. PU profiles also excel in insulation and mechanical performance in energy storage batteries, and transparent front sheets based on composites enable high light transmittance while demonstrating exceptional strength for solar panels. 

In construction, PU windows and doors are suited for near-zero-energy buildings because of their excellent insulation. In infrastructure projects, PU composites are widely used in power poles, railway sleepers, and cable trays for their durability, weather resistance, and low maintenance costs.

Note: Covestro LLC will be exhibiting at The Battery Show North America at Huntington Place in Detroit, October 7 - 10, 2024.