One with 40mm length also being developed
Samsung SDI was currently testing multiple versions of 4680 cylinder batteries which it started developing for customer Tesla, TheElec has learned.
It is testing at least two versions of the batteries, including one that follows the original specification announced by the US electric vehicle (EV) giant which rivals LG Energy Solution and Panasonic had announced they will be manufacturing.
The other one has a height length below 80mm (4680 meaning a diameter of 46mm and height of 80mm) of between 40mm to 60mm, sources said.
This version will however retain the diameter of 46mm, the sources said.
Samsung SDI was retaining the 46mm diameter but developing different lengths to win over multiple customers besides just Tesla.
It is considering offering the batteries to BMW, Volva and Stellantis, the sources said.
For example, two 46mm diameter batteries with lengths of 40mm can be stacked together, making a battery pack with two layers.
This combined with module and packaging technology can increase the combined energy density, they said, but it could get heavier and cost more.
Samsung SDI was also considering shortening the length of the batteries to lower production difficulties.
Longer batteries make the jelly roll process __ in which cathode, anode, separator and other materials are rolled together __ difficult due to alignment issues that could happen.
A longer length for the battery also means that electrolytes can be leaked out easier when they are injected. The area between the can and the cap must be cleaned as well, in which Samsung SDI is planning to use etching laser technology to do so.
Other thing to note is that 4680 batteries don’t have tabs __ the protruding tabs are folded in, which requires additional production equipment during production.