Is It Better To Use Steel or Aluminum For The Shell of Lithium Battery?

Is it better to use steel or aluminum for the shell of the lithium battery? The shell materials of lithium batteries are generally of two types: aluminum and steel. The requirements for the shell of a power lithium battery are getting higher and higher. In the early days, lithium battery was a steel shell battery, and the shell material was steel. Since the metal expansion coefficient of steel is not as good as that of aluminum shell, the probability of explosion when the battery is short-circuited is higher than that of aluminum shell.

 

Is It Better To Use Steel Or Aluminum For The Shell Of Lithium Battery?

There are only a few types of lithium battery shells on the market now. However, according to the editor, the most are steel and aluminum. The usage of these two shells is comparable, but they always have their advantages and characteristics.

 

In the early days, square lithium batteries were mostly steel shells, mostly used for mobile phone batteries. Later, due to the low weight-to-energy ratio of steel shells and poor safety, they were gradually replaced by aluminum shells and soft-package lithium batteries. But in columnar lithium batteries, there is another scene. Most manufacturers use steel as the material of battery shells.

 

Because the physical stability of steel materials is much higher than that of aluminum shell materials, after the design structure optimization of various lithium battery manufacturers, the safety device has been placed inside the battery core. The safety of steel shell column batteries has reached a new height. At present, most of the battery cells of laptop batteries are carried by steel shells.

 

Battery steel shells need to have certain corrosion resistance and high-temperature resistance characteristics, which also have a great impact on the use of steel shell products. When users usually use steel shell products, if the product's corrosion resistance is not high, or it has no resistance to high-temperature environment, it will reduce the application of steel shell products. Therefore, when selecting steel shell products, it is necessary to meet the most basic production requirements.

 

An aluminum shell is a lithium battery shell made of aluminum alloy material, mainly used in square lithium batteries. The reason why lithium batteries are packaged in aluminum shells is that it is light and safer than steel shells. The aluminum shell alloy material structure has significant safety performance considerations, which can be expressed by material thickness and expansion coefficient.

 

The reason why lithium batteries of the same capacity are lighter than steel shells is that aluminum shells can be made thinner. From the working mechanism of lithium batteries, when charging, lithium ions are deintercalated and the volume of the positive electrode expands; when discharging, lithium ions are intercalated from the positive electrode and the negative electrode expands; both will cause physical expansion, and the expansion coefficient can be reduced by appropriate alloy formula.

 

Defects of lithium battery steel shell

Battery steel shell defects are caused by many aspects, some are caused by surface and internal defects of raw materials, and some are caused by stamping processing. The surface quality of the material is affected by the surface quality at the time of leaving the factory, as well as the intermediate processing and distribution links, storage and use conditions.

 

1. Wiredrawing

One or more visible linear defects that run through the entire steel shell appear on the steel shell.

2. Scratches

On the lithium battery steel shell, there is a ∪-shaped non-open shape. This scratch defect is caused by scratches on the surface of the battery steel belt, and scratch marks can be found on the corresponding steel belt surface. According to the degree, it can be divided into shallow scratches and deep scratches. Among them, deep scratches sometimes cause the battery shell to crack, and this defect is often judged as a "sand eye" defect.

3. Dot-shaped pits

Irregular dot-shaped pits on the steel shell are often misjudged as "sand holes" defects.

4. Sand holes

In the production process of battery shell steel, the typical defect is sand hole defects. The causes of sand holes can be divided into surface defects of steel plates, steel inclusions, user mold maintenance and nickel plating in the post-process.

 

Summary: Aluminum shells for lithium batteries are better than steel shells. Although the price of aluminum shells is slightly higher than that of steel shells, they have abundant resource supply, large construction scale, advanced technology, small environmental impact, energy saving and emission reduction, and high profitability. However, steel shells have superior performance, strong impact resistance, and will still dominate the market in the future from the perspectives of market, technology, economy, and engineering.

 

After understanding the advantages and characteristics of steel shells and aluminum shells for lithium batteries, you will know whether steel shells or aluminum shells are better for battery shells! There is an explosion-proof hole on the battery core of the aluminum shell. Moreover, the capacity of the aluminum shell is high, and all batteries now use aluminum shells.

 

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https://www.stamping-welding.com/aluminum-battery-cases/battery-aluminum-square-housing.html

 

 

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