1, Lightweight demand and application of aluminum alloy
The lightweight design of new energy vehicles is of great significance for improving range, energy conservation and emission reduction. As the core component of new energy vehicles, the weight of power batteries directly affects the energy consumption and performance of the vehicle. Although traditional steel shells have high strength, their high density is not conducive to achieving lightweight goals. In contrast, aluminum alloy has the characteristics of low density and light weight, significantly reducing the overall weight of power batteries. For example, at the same capacity, aluminum alloy battery casings are thinner and lighter than steel casings, which is crucial for improving the range of electric vehicles.
2, The physical and chemical properties of aluminum alloys
The reason why aluminum alloy has become an ideal choice for power battery casings is also due to its various physical and chemical properties. Firstly, aluminum alloy is easy to process and has good plasticity and ductility, making it easy to manufacture battery casings of various shapes and sizes. Secondly, aluminum alloy is resistant to high temperature and corrosion. Through surface treatment techniques such as anodizing and spraying, a dense protective film can be formed to effectively isolate the corrosion of external corrosive media and ensure the long-term stable operation of power batteries. In addition, aluminum alloy also has good heat dissipation performance, which can quickly transfer the heat generated by the battery to the external environment, reduce the internal temperature of the battery, and ensure its safe and efficient operation.
3, Advantages of Aluminum Alloy Battery Shell
Long service life: According to simulated aging tests, the service life of aluminum alloy shells can exceed 20 years, far exceeding traditional metals and other materials. This is mainly due to the excellent aging resistance of aluminum alloy. In different locations and climatic zones, the maximum aging thickness of aluminum surface is less than 50 μ m within 20 years, which greatly guarantees the service life of the battery.
Flame retardant, smoke-free, non-toxic: Aluminum alloy materials have excellent flame retardant properties, reaching FV0 level. The smoke level under high temperature burning is 15 level, and the smoke is non-toxic, with a toxicity level of ZA1 (quasi safe level 1). This feature can significantly reduce the harm to personnel and the environment in the event of thermal runaway or fire in the battery.
Explosion proof performance: Although the aluminum alloy battery pack casing itself does not have an explosion-proof device, its weak mechanical strength means that when the internal pressure of the battery is too high, the casing is more likely to rupture and release pressure, thereby preventing battery explosion accidents from occurring. In addition, some high-end models will also design additional pressure relief valves or explosion-proof devices inside the battery pack to further enhance safety.
Cost effectiveness: Although the initial investment in aluminum alloy may be slightly higher than that of traditional steel, considering its advantages in energy savings, increased range, corrosion resistance, and heat dissipation due to its lightweight design, its long-term operating costs are lower. Meanwhile, with the continuous advancement of aluminum alloy production technology and the promotion of large-scale applications, its cost is expected to be further reduced.
Environmental friendliness: Aluminum alloy is a recyclable material that can effectively reduce environmental costs during battery production. This is in line with the current trend of green and low-carbon development, and is also one of the sustainable development goals pursued by the new energy vehicle industry.
4, Practical application cases
Taking Geely Galaxy L7 as an example, its battery adopts an aluminum alloy shell and is equipped with a "cross reinforcement beam" inside. In addition, the crossbeam design at the front and rear ends of the battery pack shell provides strong protection for the battery. Leave sufficient clearance between the battery cell and the casing to provide greater collision buffering space. In addition, the Galaxy L7 is also equipped with the "S.H.I.E.L.D. Battery Safety System", which performs excellently in the industry's most difficult and rigorous battery needle puncture test, without catching fire, exploding, or emitting smoke, and the highest temperature throughout the test does not exceed 40 ℃. These designs and technological innovations together ensure the safety and reliability of the battery.
