Views: 5 Author: Site Editor Publish Time: 2024-04-24 Origin: Site
Is aluminum shell or steel shell material better for lithium iron phosphate batteries? There are only a few types of battery casings available on the market now. But according to my understanding, the most common ones are still steel shells and aluminum shells. The use of these two shells is similar, but they always have their own advantages and characteristics. Today, I will talk to you about whether aluminum shell or steel shell material is better for lithium iron phosphate batteries?
Before answering the question of whether aluminum shell or steel shell is better for lithium iron phosphate batteries, our first choice is to take a look at what steel shell and aluminum shell are, and what are their respective advantages and characteristics? As long as you understand these, it will be very clear to talk about this issue again.
Aluminum shell is a type of lithium battery shell made of aluminum alloy material, mainly used in square lithium batteries. The reason why lithium batteries are packaged in aluminum shell is because of its lightweight and safer than steel shell.
There are two types of aluminum shell designs: square corners and rounded corners. The material of aluminum shell is generally aluminum manganese alloy, which contains main alloy components such as Mn, Cu, Mg, Si, Fe, etc. These five alloys play different roles in the aluminum shell of lithium iron phosphate batteries, such as Cu and Mg improving strength and hardness, Mn improving corrosion resistance, Si enhancing the heat treatment effect of magnesium containing aluminum alloy, and Fe improving high-temperature strength.
The construction of aluminum shell alloy materials has significant safety performance considerations, which can be represented by material thickness and bulging coefficient. The reason why lithium batteries with the same capacity are lighter than those with steel shells is because aluminum shells can be made thinner. From the working mechanism of lithium batteries, during charging, lithium ions are deintercaled and the positive electrode volume expands; During discharge, lithium ions are embedded from the positive electrode and expand from the negative electrode; Both will cause physical expansion, and the expansion coefficient can be reduced through appropriate alloy formulations.
In the early days, most square lithium batteries were made of steel shells, which were mostly used for mobile phone batteries. Later, due to the low weight to energy ratio and poor safety of steel shells, they were gradually replaced by aluminum shells and flexible packaging lithium batteries.
However, in cylindrical lithium batteries, there is another scenario where the vast majority of manufacturers use steel as the shell material for the battery. Due to the physical stability and pressure resistance of steel materials, they are much higher than aluminum shell materials. After optimizing the design structure of various manufacturers, safety devices have been placed inside the battery cells, and the safety of steel shell cylindrical batteries has reached a new height. Currently, the majority of laptop battery cells use steel shells as carriers.
PVC heat sealing: The specific outer shell packaging form used for lithium iron phosphate battery packs mainly depends on the specific product requirements of customers. For packaging forms that use PVC heat sealing, it is generally suitable for situations where the number of battery cells in series and parallel is not large and the overall weight is relatively light (≤ 2kg). However, for battery packs with an overall weight of ≥ 1kg, fixed brackets need to be added between the battery cells, and fiberglass panels need to be added to the periphery for protection before using PVC heat sealing.
Plastic: The use of plastic casing is mainly due to the possibility that different lithium battery packs may need to be molded after shaping, and the cost of the mold is a significant expense. For example, in the early stages of development, if the product is not yet finalized, a hand made shell can be used for sampling (the strength of the hand made shell is not as strong as the material strength after shaping). Different requirements for the material and process of the shell (especially with three protection requirements) can also affect the cost.
Metal: Metal casings are also similar to plastic casings. Before the product is finalized or there is not much demand for quantity, it is recommended to use sheet metal sampling. This is mainly because the lead time for sampling is short. If the batch is large, it is also recommended to open a mold. For metal shells with waterproof requirements, it will greatly affect the cost, and for special materials (such as titanium alloy) that require metal shells, the cost will be higher.
Lithium ion batteries have a high energy density and an average output voltage. Low self discharge, good batteries, below 2% per month (recoverable). There is no memory effect. The working temperature range is wide from -20 ℃ to 60 ℃. Superior cycling performance, fast charging and discharging, charging efficiency up to 100%, and high output power. Long service life. Free from toxic and harmful substances, it is called a green battery.
And its electrolyte is composed of organic solvents and lithium salts, most of which are non-toxic or low toxicity; However, the decomposition or hydrolysis products of lithium batteries are hydrofluoric acid and other fluorinated compounds, which have certain corrosiveness and toxicity. From this, it can be seen that the shell of lithium batteries is non-toxic, and what is toxic is the battery. However, not all batteries are toxic, and lithium-ion batteries are a relatively environmentally friendly and non-toxic type of battery.
I believe everyone has gained an understanding after reading the above content. In summary, both steel and aluminum shells have their own advantages, so the selection process also needs to be based on one's own needs.
Although the price of aluminum shell is slightly higher than that of steel shell, it has abundant resource supply, large construction scale, advanced technology, small environmental impact, energy conservation and emission reduction, and high profitability. However, steel shells have superior performance and strong impact resistance. From the perspectives of market, technology, economy, engineering, and other research and analysis, they will still dominate the future market.
No matter which material you want to use to customize the protective case of the battery, please tell us your needs and we will provide you with a satisfactory solution.
