As Composite material In critical, must-have application scenarios within the new-energy sector, battery casings have consistently drawn significant industry attention. Constrained by stringent standards related to fire resistance, mechanical performance, and national safety regulations, thermosetting composites have long dominated the mainstream market. Meanwhile, materials that offer multiple advantages—such as recyclability, high molding efficiency, and controllable costs— Thermoplastic Composites (TPC) In recent years, end-to-end technological validation has been completed, and the technology has entered the commercial deployment phase, emerging as a new mainstream direction for upgrading battery casing materials.

                                                   

Technical Traceability ： Transferring experience from fuel tank components to battery housings

Automotive plastic structural-component companies, leveraging years of expertise in fuel-tank design, chassis-component development, and metal-to-plastic conversion technologies, have strategically entered the electric-vehicle battery-pack housing market. The design logic for energy-storage systems, chassis-mounting requirements, and sealing-and-corrosion-protection needs differ from those of traditional The high degree of fit among fuel tank components lays a solid technological foundation for replacing metal battery housings with thermoplastic composites.

Early conventional un-reinforced plastics could not meet the battery casing’s stringent requirements for impact resistance, fire resistance, and structural rigidity. Drawing on its R&D experience in stiffening high-pressure fuel tanks for plug-in hybrid vehicles, the industry shifted to fiber-reinforced composite materials, adopting a development approach centered on cost-effectiveness and functional integration. This move broke away from the traditional composite-material application paradigm that focused solely on weight reduction.

 

Materials and Process Route ： Glass fiber reinforced TPC+ Molding/Injection Molding Composite Forming

The industry’s mainstream solution employs long-glass-fiber-reinforced thermoplastics, with glass fiber as the primary reinforcement and polypropylene as the resin matrix. Engineering plastics such as polypropylene (PP) and polyamide (PA6) are perfectly suited to meet the automotive industry’s demands for high-volume, low-cost mass production.

Addressing the industry pain points of fire resistance and battery thermal runaway through materials — Key breakthroughs achieved in structural collaborative design:

1. PA6 exhibits outstanding flame-retardant performance and can easily meet stringent safety standards;

2. Low cost through optimization of the shell stiffeners and flange structure PP material also passes fire safety tests successfully.

At the same time, a widespread adoption of metal–composite hybrid structures is employed, with steel and aluminum panels embedded as needed to balance localized high-strength mechanical requirements with overall cost control.

A standardized combination of forming processes has been established:

1. Large Casing : Utilizes compression molding to overcome the challenges of forming large-size, thin-walled components;

2. Small Housing : Utilizes injection molding to enhance production efficiency and dimensional accuracy;

3. Mass-production mainstream : Molding of the main body combined with injection overmolding for secondary forming, integrating the mounting structure, sealing surface, and reinforcing ribs into a single unit to achieve intrinsic sealing—no welding required. Leakage risk is eliminated, completely avoiding the hidden danger of metal corrosion.

 

Product Iteration ： Modular and CTP Battery Cell Integrated Housing Dual-Line Breakthrough

The industry has completed the development of two generations of full-scale validation prototypes, providing comprehensive coverage of mainstream battery packaging technology pathways.

1. Modular Housing

Compatible with traditional module battery solutions, adopting The D-LFT long-glass-fiber thermoplastic molding body features an outer layer of continuous glass-fiber composite panels that enhance overall structural rigidity; subsequent injection-molding overmolding integrates crash protection, sealing, and mounting functions into a single unit, enabling seamless compliance with authoritative domestic and international safety certifications such as ECE R100 and GB 38031. The battery lower housing and the underbody protective structure are critical design elements for impact resistance and fire protection.

2. CTP cell-integrated housing

Closely follow the industry trend toward The trend in CTP battery cell integration is shifting toward cost-reduction solutions centered on a PP matrix. The battery pack housing is manufactured via long-glass-fiber-reinforced PP compression molding, with injection-molded, integrated components for key functions such as cell positioning, emergency venting, and explosion-relief valves—replacing traditional foam-based structures. This approach delivers superior structural stability, reduces manufacturing waste, and aligns with the principles of green, low-carbon manufacturing.

The mass-production facility is primarily equipped with high-tonnage, automated molding lines, enabling stable production of large-size composite components while balancing R&D prototyping with scaled-up batch manufacturing.

 

Commercial application ： The bottom housing and protective components have been the first to achieve mass production.

Thermoplastic composite battery casings have now progressed from prototype development to large-scale mass production, with two core products already deployed in vehicles.

1. Battery Bottom Protective Skid板

Innovatively adopts a single-mold, dual-variety manufacturing model:

Highway version: all thermoplastic structure, lightweight and low-cost;

Off-road version: Metal + Composite material hybrid reinforcement meets high-dynamic impact conditions while reducing tooling investment costs.

2. CTP-structured battery lower housing

Adapted to high-volume vehicle platforms, with a single shell area of approximately With a footprint of just 2 square meters, this design integrates bottom protection and system sealing into a single unit, ensuring zero leakage even under impact conditions. It employs continuous glass fiber/PP combined with thin steel sheet through compression molding, followed by overmolding with glass fiber/PP injection molding, resulting in robust interfacial bonding and outstanding sealing performance. The steel component provides high stiffness and resilience, while the composite layer effectively prevents corrosion, delivering overall performance that significantly outperforms conventional aluminum alloy solutions.

Industry Value : Industry Outlook for the Texas Composite Materials Exhibition

Thermoplastic composite battery casings have emerged as a superior alternative to metal casings and conventional thermoset solutions, thanks to their corrosion resistance, high integration, recyclability, and simplified manufacturing processes. Material–structure co-optimization, compression-molding and injection-composite molding technologies, and hybrid metal–composite designs constitute the three core technological pathways in the battery-casing field, driving a comprehensive upgrade of new-energy-vehicle battery structural components toward greater efficiency, lower costs, enhanced recyclability, and sustainability.

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