With the rapid development of the new‑energy vehicle industry, lightweight design of power‑battery housings has become one of the core technologies for enhancing vehicle range and reducing energy consumption. Traditional metallic materials, constrained by high density and complex forming processes, are increasingly being replaced by composite materials. This paper systematically examines key technological advances in lightweight composite battery housings from four perspectives: material selection, structural design, forming processes, and performance validation.

Composite Material Selection and Performance Optimization

Composite materials overcome the performance limitations of single-material systems through the synergistic interaction between the reinforcement and the matrix. Carbon fiber-reinforced composites ( CFRP ) With a specific strength greater than that of steel, 5-7 times, with a density only that of steel 1/4-1/5 Its advantages make it the preferred choice for high-end vehicle models. For example, a certain carbon‑fiber battery housing weighs less than an aluminum‑alloy counterpart. 50% , the energy density has been increased to 210Wh/kg . Glass fiber-reinforced composite materials ( GFRP ) thereby securing a foothold in the mid- to low-end market through cost advantages. In addition, thermoplastic composites such as PA6+GF Through a single stage D-LFT Molding process to achieve weight reduction of the housing. 40% At the same time, it integrates crash‑worthy structural components and thermal‑management modules, streamlining the assembly process.

 

 

In material optimization, ply layup design has become crucial. By controlling the ply orientation angles (e.g., ±45° Alternating stacking, interlayer thickness, and fiber orientation can significantly enhance the impact resistance of the shell. For example, one study employed… 0.5mm Carbon fiber +3mm Aluminum foam +0.5mm The sandwich structure of carbon fiber enhances bending stiffness. 30% , while simultaneously satisfying IP67 Waterproofing and UL94-V0 Flame-retardant requirements.

 

 

Structural Design and Simulation Verification

 

Power battery housings must balance lightweight design with structural strength. By employing topology optimization and multi-objective optimization algorithms, the housing’s geometry can be precisely tailored. For example, a certain model… SMC Through modal analysis, the composite material top cover has had its resonant frequency reduced to 120Hz The following measures are taken to prevent fatigue damage caused by vibration. The lower housing, on the other hand, adopts a symmetrical arrangement. 8 A reinforced support bracket, combined with a side‑impact crossmember design, ensures that deformation under extreme loading conditions is kept within 2mm Within.

In terms of simulation validation, multiphysics coupled analysis has become the mainstream approach. Through thermal… - Thermal–mechanical coupling simulations can assess the structural integrity of the enclosure under thermal runaway conditions; electromagnetic compatibility simulations enable optimization of the enclosure’s shielding design, thereby reducing electromagnetic interference. For example, one study demonstrated that carbon‑fiber enclosures exhibit low thermal conductivity—lower than that of aluminum. 200 times) reducing the energy consumption of the thermal management system 15% , while also achieving salt-spray corrosion protection through a coating process. ≥1000 Hour.

 

 

Molding Process and Cost Control

 

The forming process directly affects the performance and cost of the shell. The autoclave molding process is suitable for high-precision applications. CFRP The housing, but the share of equipment investment is as high as 60%； RTM The resin transfer molding process, by employing a fast-curing resin system, reduces the molding cycle to 2 Within hours, it is suitable for mass production. For example, a certain model… PA6+GF The thermoplastic housing adopts D-LFT Process, achieving the production time per unit ≤3 minutes, representing an efficiency improvement over conventional stamping processes 80%。

In terms of cost control, material recycling and process innovation have emerged as key areas for breakthroughs. The use of recycled carbon fiber and bio-based resins reduces material costs. 30% ; and laser welding, D-LFT By contrast, the no‑soldering process reduces post‑processing steps and lowers manufacturing costs. For example, a certain all‑plastic housing achieves enhanced functional integration through injection molding. 50% , while simultaneously satisfying GB 18384-2020 Fire safety regulations.

 

 

Performance Verification and Standardization System

 

Power battery casings must pass rigorous performance verification. In terms of mechanical properties, the tensile strength must… ≥400MPa , flexural strength ≥300MPa ; In terms of environmental adaptability, it is necessary to pass -40℃ To 85℃ thermal cycling tests and 1000 Hour-long salt spray corrosion test. For example, a certain aluminum foam sandwich-structured housing in… 5mm At this thickness, the density is only that of aluminum alloy. One third , increased flexural stiffness 25%。

 

 

In terms of the standards system, the industry is steadily being refined. UL94-V0 Flame-retardant certification, IP67 Waterproof certification and GB/T 31467.3-2015 Compression testing has become a basic threshold. In addition, fire‑exposure testing for thermal runaway scenarios ( 1000℃ Flame exposure ≥5 minutes) and vibration testing (monitoring voltage) / (Temperature is normal), making it a differentiating competitive advantage for high-end models.

The development of lightweight composite battery housings requires striking a balance among material innovation, structural design, process optimization, and performance validation. In the future, as carbon‑fiber costs decline and thermoplastic composite manufacturing technologies mature, composite‑material vehicle bodies will gradually replace traditional metal structures, helping to push the range of new‑energy vehicles beyond current limits. 1000 The kilometer milestone. Meanwhile, the development of lightweight composite‑material battery housings—supported by standardized testing methods and a full‑life‑cycle assessment framework—requires striking a balance among material innovation, structural design, process optimization, and performance validation. Looking ahead, as carbon‑fiber costs decline and thermoplastic composite manufacturing matures, composite‑material housings will gradually replace conventional metal structures, helping to push the range of new‑energy vehicles beyond its current limits. 1000 The kilometer threshold has been reached. Meanwhile, the development of standardized testing methods and a full‑life‑cycle assessment framework will provide the technical foundation for large‑scale industry deployment.

 

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