Tesla car battery
Powerful Battery Cells
Inside a Tesla Model S battery pack (Source:
Electrek)
cells, but thousands of small, cylindrical, lithium-
ion commodity cells like those used in consumer
electronics. It uses a version of these cells that is
designed to be cheaper to manufacture and lighter
than standard cells because of the advanced
thermal management system and an intumescent
chemical in the battery to prevent fires. Panasonic
is the sole supplier of the cells for Model S, Model
X, and Model 3 and co-operates with Tesla in
its huge battery factory called Gigafactory in
Nevada, USA.
Battery cells are simple devices consisting of three
basic components: two electrodes, the negative
anode and the positive cathode separated by a
chemical “soup”, called the electrolyte. When
Lithium ion batteries are charged, Lithium ions
are forced to migrate to the negative electrode
where they are deposited. During discharge the
Lithium ions reverse direction for the Cathode.
Tesla has managed to pack more and more
battery cells to power its cars. The first generation
18650 form battery cells, used by the company
in Tesla’s first-generation Roadster, are still used
in the Model S and Model X. The latest 21700
cells are used exclusively in the Tesla Model 3
and in energy storage products. They are a huge
improvement over the 18650 battery cells with
regard to energy density (by as much as 30%)
and packaging possibilities. The 21700 cells
have a diameter of 2 1mm, length of 70mm and
volume of 24.245mm³. This is 46% more than
the 18650 cells. “They are also about 15% more
energy efficient,” according to a statement by J. B.
Straubel, Tesla’s chief technology officer. Energy
density is said to be 877.5Wh/L and cell capacity
is 21.275Wh.
25