What is the battery tab?

The tab is a component of soft pack lithium-ion battery products. The battery is divided into positive and negative electrodes, the pole lug is the metal conductor that leads from the positive and negative electrodes in the battery cell. Commonly known as the positive and negative ears of the battery is the contact point when charging and discharging. The positive electrode of the battery uses aluminum (Al), the negative electrode uses nickel (Ni), and the negative electrode is also nickel-plated with copper (Ni-Cu). And they are both made of a composite of two parts: the film and the metal flat wire.

Classification of the tab

1. According to the raw material of the metal band of the tabs:

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

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

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

2. According to the tab rubber (in the Chinese market)

(1) Vinyl pole ear: generally used in the low-end digital class of small batteries.

(2) Yellow rubber pole lugs: Generally used in low to medium-end power batteries and high magnification batteries.

(3) White rubber pole lugs: generally used in high-end digital batteries, power batteries, and high magnification batteries.

3. The finished packaging of tabs:

(1) Disc type tab (the whole metal flat wire is wound into a disc after adding film to the equipment). It used in automated production lines.

(2) Plate type tab (metal strip with film cut into individual pieces, then placed in rows with two thin transparent plastic sheets sandwiched in the center), used in general production lines.

The raw material for the battery tab

Alloy 1050 is formed by adding a small amount of copper to pure aluminum. It has excellent forming and processing characteristics, high corrosion resistance, good weldability and electrical conductivity.

TU1 is oxygen-free copper, with very low oxygen and impurity content, high purity, excellent electrical and thermal conductivity, excellent ductility, low permeability, no “hydrogen disease” or very little “hydrogen disease”; processing functions, welding, corrosion, and cold resistance are good.

 How to test the battery tab？

7.1 Electrolyte immersion test after immersion

7.2.1 Heat seal strength test after electrolyte immersion

7.2.2 Electrolyte immersion test after immersion

7.3 Bending test

Thickness <0.2mm: aluminum, nickel Tab ≥ 7 times; nickel copper plating ≥ 6 times.

Thickness ≥ 0.2 mm: aluminum, nickel, nickel-plated copper Tab ≥ 5 times.

7.4.1 Copper nickel plated power tabs – Plating adhesion test

Requirements: No blackening of the plating layer.

When the plating function is lacking under a long time high current, driving boom, etc.

Inside the cell – plating falls off to the pole piece – micro-short circuit – self-discharge.

Outside the core – PACK welding at the plating is loose – contact with the internal resistance becomes large – or welding falls off.