Tabs are metal conductors that lead the positive and negative electrodes out of the battery cell. Simply put, they are the "ears" of the battery's positive and negative poles, serving as contact points 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 usually 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 with only one positive tab and one negative tab in the battery. Single-tab technology is relatively mature, with many years of process accumulation, and the cost is relatively low. Under the same volume, single-tab batteries have higher energy density, resulting in longer endurance.
Double-tab battery cell
A double-tab battery cell refers to a configuration with two positive tabs and one negative tab in the battery. This design can form two circuits on one battery 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 ingeniously uses the entire tail of the current collector as the tab. Through the cover plate (current collector plate) structure design, the tab conduction area and the connection area at the connection point are increased, and the tab conduction distance is shortened. The internal resistance of a full-tab battery is reduced by approximately 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, pulse discharge at 200A, and the extremely low internal resistance supports superfast charging performance at a 5C charge/discharge rate, 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 particularly advantageous in high-rate application scenarios 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.
