Tesla is the world's largest electric car manufacturer and many wonder what batteries the company uses. Is there a secret battery type that allows it to achieve success?

Well, if we look at almost 20 years of Tesla, it seems that the secret lies not in a particular battery, but in the approach - very pragmatic, flexible, geared to constant evolution, adaptation, and looking for opportunities.

Battery cell form factor

When the company started its journey with the original Tesla Roadster, there were not many types of lithium-ion batteries to choose from. Tesla simply decided to use 18650-type (recently called 1865) cylindrical batteries, designed for general purpose (slightly adapted to EVs).

They were difficult to use, due to a high number of small cells (low capacity) in the battery pack (several thousand), but available at a consistent quality and in high volume. With outstanding engineering to handle electrical and thermal management (liquid cooling), Tesla went the pragmatic path (some other companies started to use the new pouch or prismatic cell types at the time).

The 1865-type cells were used in the Roadster and Model S/Model X (including the refreshed ones). The primary supplier of those cells for Tesla is Panasonic (from Japan).

Later on, Tesla figured out that it would be better to have a larger battery cell (higher capacity per cell, and a lower number of cells), optimized for electric cars. This is how the 2170-type cylindrical cell entered the market in high volume for the Tesla Model 3/Tesla Model Y as well as for energy storage products.

The 2170-type was initially produced by Panasonic at the Tesla Gigafactory 1 in Nevada (currently at roughly 38-39 GWh/year). In recent years, LG Chem's LG Energy Solution has also become the supplier of such cells for Tesla - producing them in China, mainly for the Tesla Giga Shanghai plant.

The newest and so far the largest cylindrical cell format, the 4680-type, entered the market this year. The cell is physically 5-times bigger than the 2170-type, which allows for further optimizing the system and introduction of some new technologies. However, the size and new solutions make it challenging to produce. This is why Tesla has started its own, in-house development and production in California and Texas, and encourages suppliers - including Panasonic - to accelerate their efforts.

Those are the three cylindrical cell types used by Tesla in its electric cars, but there is a fourth one - prismatic type, for the LFP batteries, supplied by CATL. As of Q1 2022, almost half of all Tesla cars were equipped with prismatic LFP batteries. It's another clear example of pragmatic adaptation to market demand, as the prismatic LFP batteries are the foundation of the less expensive, entry-level Tesla models.

Tesla battery cell types:

  • 1865-type (18 mm in diameter and 65 mm tall)
    use: Roadster (original), Model S, Model X
  • 2170-type (21 mm in diameter and 70 mm tall)
    use: Model 3, Model Y
  • 4680-type (46 mm in diameter and 80 mm tall)
    use: Model Y Made-in-Texas (in the future also Model Y from Germany and new models)
  • prismatic
    use: entry-level Model 3 and Model Y

Battery cell chemistry

All of Tesla's traction batteries are lithium-ion batteries, but they are not all the same. There are several main cathode chemistries, each of which evolves over the years.

The three main cathode types in Tesla EVs:

  • nickel-cobalt-aluminum (NCA)
  • nickel-cobalt-manganese (NCM)
  • lithium iron phosphate (LFP)

The two first - NCA and NCM - have a high energy density, which predisposes them to use in long-range versions of Tesla cars. Those two types were used in cylindrical cells (NCA in 1865 and 2170 from Panasonic, NCM in 2170 from LGES).

The LFP is a less energy-dense type. It does not contain any nickel or cobalt, which makes it less expensive. It's a perfect fit for entry-level models and energy storage systems. Tesla uses prismatic LFP cells from CATL.

In the recent 2021 Impact Report, Tesla explains that it "will continue to advance a diversified cathode strategy for LFP, nickel-rich and manganese-rich cathodes to address various market segments for vehicle and energy storage products and provide future flexibility based on raw materials availability and pricing."

Tesla tries to increase nickel content and reduce the cobalt content in NCA and NCM batteries, which would reduce the cost and improve energy density (and range). However, it's not easy to remove cobalt because of its role in the safety and longevity of the battery.

"Tesla will continue to advance a diversified cathode strategy for LFP, nickel-rich and manganese-rich cathodes to address various market segments for vehicle and energy storage products and provide future flexibility based on raw materials availability and pricing."

The company also notes that in the coming years, its absolute cobalt demand will increase, because the production growth of batteries and vehicles is forecasted to outpace the overall rate of cobalt reduction on a per-cell basis.

We must also remember that the cathode is not the only element of the battery and there are constant improvements to all elements, including the anode (silicon vs. graphite content) and the electrolyte.

Battery suppliers

Finally, the battery suppliers. Initially, and for a long time, Tesla's primary battery supplier happened to be Panasonic - 1865- and 2170-type cells with NCA chemistry. But later it was joined by LG Energy Solution (2170-type cells with NCM chemistry) and CATL (prismatic LFP chemistry).

On top of that, Tesla has started its own battery production - the 4680-type cell with undisclosed chemistry (but most likely a high energy dense one). Tesla's 1 millionth cell was produced in California in January (an electric car might need up to about a 1,000 such cells).

In other words, we can see progressing diversification:

  • Panasonic:
    Japan: 1865-type NCA (main use: Model S/Model X)
    US (Gigafactory 1 in Nevada: 2170-type NCA (main use: Model 3/Model Y from California)
  • LG Chem's LG Energy Solution:
    China: 2170-type NCM (main use: MIC Model 3/Model Y and MIG Model Y)
  • CATL:
    China: prismatic LFP (main use: entry-level Model 3/Model Y globally)
  • Tesla:
    California/Texas: 4680-type, undisclosed chemistry (main use: Made-in-Texas Model Y)

* there might be other suppliers and other use cases (supplier/cell format/chemistry), but those are general ones.

As we can see, the battery topic has become quite complex. It seems that Tesla moves forward with new types of batteries, but so far does not resign from the previous ones (partially due to lack of battery manufacturing capacity and additional cost to redesign products for new cells).

Only time will tell how fast and successful the latest branch of 4680-type batteries will be.

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