A tab is a metal conductor that draws out the positive and negative electrodes from the battery cell. Simply put, it is the "ear" of the battery's positive and negative poles, serving as a contact point during charging and discharging. This contact point is not the copper piece we see on the battery's exterior but an internal connection within the battery. Tabs play a crucial role in the battery system, with primary functions including current transmission and heat conduction. The positive tab of a battery typically uses aluminum (Al) material, while the negative tab uses nickel (Ni) material. Some negative tabs use nickel-plated copper (Ni-Cu) material. These tabs are composed of two parts: a film and a metal strip.
Single-tab battery cell
A single-tab battery cell refers to a configuration where the battery has only one positive tab and one negative tab. Single-tab technology is relatively mature, with years of process accumulation, and is relatively low-cost. With the same volume, single-tab batteries have higher energy density, thus providing longer endurance.
Double-tab battery cell
A double-tab battery cell refers to a configuration where the battery has two positive tabs and one negative tab. This design can form two circuits on a single cell, distributing the large power fast charging current and voltage. Due to the dual charging design, double-tab battery cells have higher charging efficiency and are suitable for large power fast charging.
Full-tab battery cell
A full-tab battery cell (also known as a tabless design) refers to a design that cleverly uses the entire tail of the current collector as the tab and increases the tab's conduction area and connection area through the cover plate (current collector plate) structure design, shortening the tab's conduction distance. The internal resistance of full-tab batteries is reduced by about 70% compared to traditional batteries, the high-current discharge temperature is reduced by 35%, and the cycle life is improved by 100% compared to traditional batteries. It also supports continuous discharge at a maximum current of 100A and pulse discharge at 200A. The extremely low internal resistance supports the battery's 5C superfast charging performance, achieving 80% SOC superfast charging in 10 minutes. Additionally, full-tab battery cells exhibit superior low-temperature performance and better safety, making them suitable for various harsh application environments. They are especially ideal for high-rate applications such as power tools, garden tools, and household cleaning, providing high-performance, stable, and reliable power supplies.
Currently, 11 companies have launched full-tab battery products, including Ampace, BAK, CATL, EVE, HENGTAI, RELiANCE, Panasonic, and Tesla. In November 2024, Highstar also released its latest full-tab series battery cells at the Battery Experts Forum in Germany.
