Why Do Lithium Batteries Use Aluminum Foil for the Anode?

For lithium-ion batteries, the anode current collector is usually aluminum foil and the anode current collector is copper foil. In order to ensure the internal stability and internal stability of the current collector, the purity of both is required to be above 98%. With the continuous development of lithium battery technology, whether it is used for lithium batteries for digital products or batteries for electric vehicles, we all hope that the energy density of the battery is as high as possible, and the weight of the battery is getting lighter and lighter. The most important thing in the current collector is to Reduce the thickness and weight of the current collector to reduce the volume and weight of the battery intuitively.

Why use aluminum foil for the positive electrode of lithium-ion batteries and copper foil for the negative electrode?

1.Copper foil and aluminum foil have good conductivity, soft texture, and low price.

We all know that the working principle of a lithium battery is an electrochemical device that converts chemical energy into electrical energy. In this process, we need a medium to transfer the electrical energy converted from chemical energy. Conductive materials are needed here. Among ordinary materials, metal materials are the most conductive materials, and among the metal materials, copper foil and aluminum foil are cheap and conductive. Among the metal materials, copper foil and aluminum foil are also softer metals. Finally, the cost of battery preparation is considered. Relatively speaking, copper foil and aluminum foil are relatively cheap, and there are abundant copper and aluminum elements in the world.

2.Copper foil and aluminum foil are relatively stable in the air.

Aluminum is easy to chemically react with oxygen in the air, forming a dense oxide film on the surface of the aluminum to prevent further aluminum reaction, and this thin oxide film also has a certain protective effect on aluminum in the electrolyte. Copper itself is relatively stable in air and basically does not react in dry air.

3.The positive and negative potentials of lithium batteries are determined.

The positive electrode potential is high, the copper foil is easily oxidized under high potential, while the oxidation potential of aluminum is high, and the surface of the aluminum foil has a dense oxide film, which also has a better protective effect on the internal aluminum. Both are used as current collectors because they have good electrical conductivity, soft texture (maybe it will also be good for bonding), and are relatively common and cheaper. At the same time, an oxide protective film can be formed on both surfaces.

Why choose an aluminum laminate film for batteries?

1. The aluminum laminate film for pouch battery box packaging has good barrier properties, electrolyte stability, cold stamping formability, puncture resistance, and insulation.

 The original heat-sealing strength of the aluminum laminate film for pouch battery box packaging is 88.1N/15mm, which is one of the advantages of our products. Even if the electrolyte contaminates the hot surface, the heat seal strength can still reach 85.9N / 15mm, which can still meet the requirements. Especially after being immersed in the electrolyte, it still has a high heat seal strength and exhibits excellent electrolyte resistance.

2. It is widely used in mobile communications, notebook computers, MP3, handheld DVD players, and others with polymer lithium-ion batteries and ordinary lithium-ion batteries. 

The size can be customized according to requirements. If you want to get more information about the good quality aluminum laminate film, please contact us.