Ever since Tesla announced the new 4680 battery cell for the future at the Tesla Battery Days three years ago, there has been a real buzz around this new cylindrical battery cell. Although the 46 mm diameter and 80 mm long cell has only been used so far in the Tesla Model Y, there has been an increasing amount of interest and announcements, especially from the automotive industry. In addition to Tesla as a pioneer, OEMs such as BMW and General Motors have also announced their intention to use the cell in the future. At the same time, there is an expanding field of battery manufacturers that are building production capabilities, or at least aiming to build manufacturing capabilities. LG Energy Solution hopes to set up a sample production line in Ochang, South Korea this year, while Panasonic hopes to set up a large-scale production line in Wakayama, Japan. Samsung SDI and BAK are also conducting trial production, and CATL and EVE Energy have signed contracts to build Gigafactories as qualified suppliers for BMW. In the automotive industry, expectations for batteries are high: high power density and fast charging capabilities, more efficient integration into the battery pack or vehicle chassis, and cost advantages due to the simpler manufacturing process of cylindrical cells. Although the size of this cell is large compared to other cylindrical cells such as 18650 and 21700, its size and battery capacity are still much smaller than the latest generation of prismatic cells. For example, the internal volume of a 46 mm cell with a height of 80 mm is about 120 ml. The volume of the “blade” battery produced by BYD is slightly less than 1.2 liters.
For OEMs, the use of new cylindrical battery packs may therefore still require a high level of integration. But at the same time, there is flexibility in the mechanical and electrical design of the battery pack: for example, NIO and BMW have announced their intention to use 800 V structures in the future. Due to the small number of individual cells in large-format batteries, it is not possible to achieve such high system voltages when connected in series. With the new 4680 cylindrical cells, a typical battery pack can achieve high system voltages even if 3 to 5 cells are connected in parallel.
