SHANGHAI, Nov 16 (SMM) - Tesla unveiled its 4680 battery during its Battery Day in September 2020, which is a cylindrical battery with a diameter of 46mm and a height of 80mm. Tesla expects that its 4680 battery will have five times more capacity, 16% more driving range and 14% lower costs than the 2170 battery. At present, domestic car companies mainly use prismatic battery. Only Tesla, Daimler, Nissan, Renault, Volkswagen and Hyundai use cylindrical pouch power batteries on a large scale. However, it takes time for car companies to change their battery types. With reference to the speed at which the 2170 battery replaces the 18650 battery, and assuming that the 2170 battery is still the mainstream battery in 2022, it will be gradually replaced by the 4680 battery by 2023 and fully replaced by 2024.
Bigger size, and higher battery capacity due to the use of high nickel ternary cathode materials. The 4680 battery has 5 times more battery capacity than the 2170 battery (not a 5 times increase in energy density), and the increase in battery capacity will also lead to a 16% increase in driving range.
"Tabless” structure allows thermal runaway to be effectively controlled. In terms of heat dissipation, the advantages of cylindrical battery cells are that the capacity of a single unit is low, and the heat release of a single electrical runaway is not easy to spread. Besides, the arc-shaped surface suppresses the heat transfer between the batteries to a certain extent. The cylindrical battery cell itself has a certain threshold for thermal runaway. There is more room for fault tolerance in the module part.
Fewer battery cells and higher space utilisation rate. The cost reduction is mainly due to the fact that the 2170 cylindrical power battery requires 4,400 cells, while the 4680 battery only needs 950 cells, which means higher space utilisation rate and higher assembly efficiency. And compared to the 2170 battery, the 4680 battery reduces the amount of raw materials that do not provide energy density, such as battery separators and steel shells, so as to reduce the costs.