The core reasons for choosing aluminum shells for lithium batteries can be summarized as the following advantages: 1. Lightweight and economical The density of aluminum (2.7 g/cm3) is only 1/3 of that of steel, which significantly reduces the weight of the battery and meets the lightweight needs of electronic devices and electric vehicles. The material and processing costs are low, and it is suitable for mass production. 2. Corrosion resistance and safety Aluminum produces a dense alumina passivation film in a high-voltage environment (3.0-4.5V) to resist electrolyte corrosion and has excellent thermal conductivity 237 W / m . K ) Conducive to heat dissipation, with the design of safety valve It can relieve pressure in time to reduce the risk of thermal runaway. 3. Conductivity and structural optimization Aluminum is both the shell and the cathode current path, which can be seamlessly connected with the aluminum foil current collector to reduce internal resistance; Simplified structure meter, improve the efficiency of energy transmission. 4. Processing adaptability Aluminum has good ductility and is easy to stamping the complex shape of ↓-shaped, cylindrical or pouch cells; The laser welding technology is mature, the sealing is strong, and the water and oxygen intrusion are effectively isolated. Exception: Nickel-plated shells are used in extreme environments or when high mechanical strength is required, but at the expense of lightweight and cost advantages. Summary: Aluminum shell has become the mainstream choice of lithium battery shell with the comprehensive advantages of lightness, corrosion resistance, conductivity, easy processing, good heat dissipation and low cost.
