An Insight into Lithium battery tabs

Battery tabs are a component of lithium-ion polymer battery products. Usually, we divide the battery into positive and negative electrodes. And the tab is the metal conductor that leads the positive and negative electrodes from the battery cell. Commonly speaking, the positive and negative battery tabs are the contact points when charging and discharging.

The battery tab is a “connection, conductivity, seal”. Connection means the connection between the inside and outside of the battery. The connection between the tab rubber and the aluminum plastic film. Conductive means it draws out the electricity and it generates the circuit through the tab. Seal means the seal between the rubber strip and the metal strip and the seal between the rubber strip and the aluminum plastic film.

Classification of polymer lithium battery tabs

1. Classification according to the material of the metal ribbon of battery tabs:

We divided Battery tabs into three materials. And we use aluminum (Al) material for the positive electrode of the battery. Using nickel (Ni) material for the negative electrode. And nickel-plated copper (Ni-Cu) material is also available for the negative electrode. There are two parts that make up them. The film and the metal strip. The film is the insulating part on the pole tab. And its function is to prevent the short circuit between the metal strip and the aluminum-plastic film when the battery is encapsulated. And we heat it(about 140℃) to prevent leakage by heat sealing it with the aluminum-plastic film.

1) Aluminum (Al) tabs: Generally used as a positive tab. ut also used as a negative tab if the battery is lithium titanate negative tab.

2) Nickel (Ni) tabs: usually used in the negative electrode. mainly used in digital small batteries, such as cell phone batteries, mobile power batteries, tablet PC batteries, smart transfer device batteries, etc.

3) Copper-plated nickel (Ni-Cu) tabs: used as negative electrode tabs, mainly used in dry power cells and high-rate batteries.

2. Classification by finished packaging of battery tabs

1) Disc-type battery tab (wounding the whole metal strip into a disc by adding film to the equipment). Usually, we use it in automated production lines.

2) Plate-type battery tab (metal strip with film cut into individual pieces, then placed in rows with two thin transparent plastic sheets sandwiched between them), used in general product lines.

The role of battery tabs

The role of the battery tabs is to prevent short circuit failure between the metal strip and the aluminum plastic film when the battery is encapsulated, and to prevent leakage by heating (about 140°C) and heat sealing the aluminum plastic film together. There are two pieces of film to sandwich the metal strip in the middle to make a battery tab. The black film often used in the market is a three-layer structure: melanin, with a melting point of 66°C; PE, with a melting point of 105°C; and PP, with a melting point of 137°C. The finished packaging of polar ears is divided into disk type (the whole metal strip is wound into a disk after adding film through the equipment) and plate type (the metal strip is cut into individual pieces after adding film, and then placed in rows with two thin transparent plastic sheets sandwiched in the middle).