Lithium-ion battery shell material generally has two types of aluminum and steel, this material made out of lithium-ion battery shell has its characteristics, so which one is better?
· Aluminium battery case
The aluminum shell material is generally 3xxx series aluminum manganese alloy containing essential components such as Mn, Cu, Mg, Si, Fe, etc. These five alloys play different use in the lithium-ion battery aluminum shell, such as Cu and Mg, to improve strength and hardness. Si can enhance the heat treatment effect of an aluminum alloy containing magnesium to improve corrosion resistance, and Fe can improve high-temperature strength.
The lithium-ion battery with the same capacity is lighter than the steel case because the aluminum case can be made thinner.
From the working mechanism of lithium-ion batteries, lithium ions are de-embedded during charging, and the volume of the positive electrode expands; lithium ions are embedded from the positive electrode during discharge, and the negative electrode expands; both will lead to the expansion of the entity, and appropriate ratios of aluminum alloy elements can reduce the bulge factor.
· Steel battery case
Battery steel shells have specific anti-corrosion properties and high-temperature resistance characteristics. These on the use of steel shell products also significantly impact the user. In the use of steel shell products in the process, if the product's corrosion resistance is not high or the high-temperature environment is not resistant will reduce the application of steel shell products.
Lithium-ion battery steel case defects
Battery steel shell defects are multifaceted: some are caused by raw material surface and internal defects, stamping processing, and material surface quality by the factory finished products, as well as by the intermediate processing distribution links, storage, and use conditions.
The steel shell presents one or more through the entire steel shell of the naked eye visible line defects.
The lithium-ion battery steel case presents irregular openings. This abrasion defect is caused by the surface abrasion of the battery steel strip, which can be found in the corresponding steel strip surface abrasion marks. The degree of distinction can be divided into shallow bruises and deep scratches. Among them, deep scratches sometimes lead to the phenomenon of battery case cracking, and this defect will often be judged as a sanding defect.
3. Point-like pits
The steel case presents irregular-shaped point-like pits, often misjudged as a sanding defect.
4. Gritty eyes
In the production process of using battery shell steel, the typical defect is a sand eye defect. Reasons for the appearance of trachoma can be divided into steel surface defects, steel inclusions, user mold maintenance, and post-process nickel plating.
Aluminium battery housing cases are better than steel cases for lithium-ion batteries.
However, the price of aluminium shell is slightly higher than the cost of steel shell, abundant resources, large construction scale, advanced technology, small environmental impact, energy saving and emission reduction, and increased profitability. However, the steel shell has superior performance and high impact resistance. It will still dominate the market in the future from the market, technical, economic, engineering, and other perspectives of research and analysis.