Aluminium Alloys For Lithium-ion Battery Casing Materials

Aluminum shell lithium battery is a battery shell made from aluminum alloy material. The aluminum shell battery is a hard shell in terms of appearance, mainly used in square and cylindrical cells.

Lithium battery packs use aluminum shell packaging because they are lightweight and safer than steel shells. Aluminum shell lithium battery is the mainstream of the current liquid lithium battery and is used in almost all areas involved in lithium batteries.

Aluminum cases are about 50% lighter than similar steel designs, which is especially important for electric vehicles (this is important for vehicles with all types of engines, but not many people are "mileage anxious" enough to have an internal combustion engine under the hood of their vehicle). The reduction in mass of the aluminum housing has been calculated to increase the range of an EV by 6%-10% compared to alternative structures.

Aluminum shell lithium battery is a battery shell made from aluminum alloy material. The aluminum shell battery is a hard shell in terms of appearance, mainly used in square and cylindrical cells.

The lithium battery shell design has square corners and rounded corners. The aluminum shell material is generally aluminum-manganese alloy, which contains the main alloy components such as Mn, Cu, Mg, Si, Fe, etc. These five alloys play different roles, such as Cu and Mg, to improve strength and hardness, Mn improves corrosion resistance, and Si can enhance the heat treatment effect of an aluminum alloy containing magnesium. And Fe can improve high-temperature strength.

With their excellent mechanical properties, low density, and high thermal conductivity, Aluminium Alloys can help improve the safety, reliability, and efficiency of lithium-ion batteries, making them an essential component of the modern world.

From the worst result, even if the battery is in case of explosion, the lithium battery aluminum case is much weaker than the bursting force of the steel case, thus causing less harm.

The lithium-ion battery shell protects the battery's internal materials and adds strength. It's typically made from materials like stainless steel, aluminum, and aluminum-plastic film. Any inert material that resists HF acid corrosion and doesn't participate in electrode reactions can be used, as long as good insulation exists between the positive and negative electrodes. The choice of material depends on the battery's application and environment, and can be customized to meet user needs.

Uses of Lithium Ion Battery Casing:

• Reduces polarization, thermal effects, improves rate performance.
• Lowers internal resistance and dynamic internal resistance increase.
• Enhances consistency and cycle life.
• Improves adhesion between active material and collector, reducing electrode manufacturing cost.
• Protects collector from electrolyte corrosion.
• Enhances high and low-temperature performance of lithium-ion batteries, improving processing performance.

Aluminum shell lithium-ion batteries are well-liked because they are light, safe, and high-performing. Lithium-ion battery casings are being made with technology that makes them both hard and light. Each casing has its own strengths and weaknesses, so it's important to choose the casing that best fits your needs.

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.

1. Drawing

The steel shell presents one or more through the entire steel shell of the naked eye visible line defects.

2.
Scuffing

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.