Lithium-ion Battery Current Collector Types

The current collector is one of the indispensable components in lithium-ion batteries.It can not only carry the active material, but also collect and output the current generated by the electrode active material.It is beneficial to reduce the internal resistance of the lithium-ion battery and improve the coulombic efficiency, cycle stability and rate performance of the battery.

The materials that can be used as current collectors for lithium-ion batteries are as follows:

1. Copper foil: Increasing the roughness of the surface of the copper foil is beneficial to improve the bonding strength between the current collector and the active material, and reduce the contact resistance between the active material and the current collector.

Correspondingly, the rate discharge performance and cycle stability of the battery are also better.

2. Copper foam: Copper foam is a three-dimensional mesh material similar to sponge, which has many advantages such as light weight, high strength and toughness, and large specific surface area.

3. Aluminum foil: During the charging/discharging process of lithium ion batteries, a dense oxide film will be formed on the surface of the current collector of Aluminum Foil, which improves the corrosion resistance of aluminum foil, and is often used as the current collector of the positive electrode in lithium ion batteries.

4. Nickel foam and nickel foil: They have good electrical conductivity and are relatively stable in acid and alkaline solutions. Nickel can be used as both positive and negative current collectors.

5. Carbon cloth, carbon fiber cloth can be used as a current collector for flexible lithium-ion batteries with its own advantages of good flexibility, electrical conductivity and electrochemical stability.

6. Carbon nanotubes (CNTs) are another type of carbon current collectors. Compared with metal current collectors, their obvious advantages are light weight and can greatly improve the energy density of batteries.

7.Carbon-coated aluminum foil/copper foil: The carbon-coated/aluminum foil current collector is a composite current collector that coats the carbon-containing composite layer on the surface of the aluminum foil.

Among them, the carbon-containing layer is composed of carbon fibers and conductive carbon black particles treated with a dispersant, which can be closely combined with the aluminum foil to improve the conductivity and corrosion resistance of the electrode.