The power battery system (battery pack) serves as the core energy source for new energy vehicles, being one of the key components. The power battery system is primarily composed of battery modules, electrical systems, thermal management systems, battery pack shells, and BMS, etc. These components are encapsulated within the shell to form the main body of the power battery system.
The primary function of the battery pack shell is to bear the battery assembly, electrical modules, cooling modules, and other power battery system components, while also protecting the battery and electrical system from damage during external collisions, impacts, and compressions of the vehicle. Traditional metal materials such as steel plates, aluminum plates, extruded aluminum profiles, and die-cast aluminum are all applied in the battery shells of different vehicle models.
Steel Shell
Steel battery case is the original material for power battery packs, generally made by welding cast steel plates. It boasts high strength and rigidity, heavy weight, and requires anti-corrosion treatment on the surface to maintain good anti-corrosion properties under long-term high-temperature conditions.
2. Aluminum Shell
Automotive power battery packs made of aluminum offer advantages such as easy processing, molding, high-temperature corrosion resistance, excellent thermal and electrical conductivity, long service life, flame retardancy, aging resistance, and explosion-proof properties. Different types of aluminum materials, including rolled aluminum plates, extruded aluminum profiles, and cast aluminum, have been widely applied in various battery pack shell projects, and have become the mainstream technical route for power battery system shells.
3. SMC Composite Materials
Sheet molding compound (SMC) is primarily composed of glass fiber (GF), unsaturated polyester (UP), low shrinkage additives, MD (filler), and various auxiliaries. SMC boasts excellent electrical properties, resistance to chemical corrosion, low thermal conductivity, and small coefficient of expansion. It also exhibits superior resistance to ultraviolet aging and fatigue, along with high strength and light weight. SMC has found applications in the production and manufacturing of battery pack shells.
Carbon Fiber Reinforced Polymer
Carbon fiber composite materials have emerged as an ideal substitute for traditional metal shell materials for battery packs. Compared to metal materials, carbon fiber has a density of approximately 1.7g/cm³. It boasts a tensile strength of 3000MPa, an elastic modulus of 230GPa, and its lightweight yet high strength properties make it resistant to high temperatures, friction, vibration, and has a low coefficient of thermal expansion.
5. PC+LFT-D Long Fiber Reinforced Thermoplastic Material
The excellent flame-retardant, dimensional stability, and mechanical properties of the PC materials complement the inherent long fiber retention of the LFT-D process, perfectly meeting the requirements for battery pack shell applications. The material features good flame retardancy, high rigidity, high toughness, and resistance to cracking, allowing the upper and lower shells to be tightly sealed, enhancing the airtightness of the battery pack during long-term use.
Under the leadership of China's rapid development in new energy vehicles, electrification has become the main trend in global automotive development. As a component of the new energy power system, the battery pack shell market is expected to see a rapid increase in size.
