To EV enthusiasts who have been monitoring the advent of new battery types – including prismatic-type and pouch-type batteries – it may seem strange that Tesla still uses cylindrical cells. This type of battery, which is often used in things like laptops and power tools, has been around for a long time. So, why is Tesla Motors still using cylindrical cells in their batteries?
Read on to find out what cylindrical battery cells are, why Tesla still uses them, and what the future may hold for Tesla’s battery technology.
What Are Cylindrical Battery Cells?
A cylindrical cell is a battery cell that is enclosed in a rigid, cylindrical casing. For example, the typical AA or AAA batteries that power your handheld games console or TV remote are cylindrical cells.
Right from the beginning, Tesla began with cylindrical batteries. Namely the 18650 cells that featured in the Roadster and continue to feature the Model S and Model X.
The name of 18650 battery cells is inspired by their dimensions, with each cell measuring 18mm x 65mm. This particular size of cylindrical battery has traditionally been used in all sorts of rechargable appliances and smaller EVs such as scooters and electric bicycles. However, Tesla was the first company to put thousands of cells together to form a battery pack large enough to power an electric car.
In contrast, some other EV manufacturers favor either prismatic battery cells or pouch battery cells. Prismatic cells are also housed within a rigid casing, but they are rectangular in shape and are often larger than cylindrical cells.
Pouch cells are soft batteries, with the component parts housed within a malleable aluminum-coated plastic film.
|EV Brands that Commonly Use Them
|Tesla, Lucid, and Rivian
|BMW, Mercedes-Benz, and Volkswagen
|Nissan, Renault and Chevrolet
Which Tesla Batteries Feature Cylindrical Cells?
So far, Tesla has introduced four different batteries within its vehicle fleet. Three of them are cylindrical-type and one of them is prismatic-type.
In a recent tweet, Elon Musk gave us reason to suspect that they won’t be adding a pouch-type battery to their inventory any time soon. Musk voiced his concern over the safety of large pouch cells and the associated risk of thermal runaway, which can ultimately result in battery fires.
|Tesla Battery Type
|Found in Tesla Models
|Battery Cell Type
|Roadster, Model S, Model X
|Model 3, Model Y
|Model 3, Model Y
|Model Y, Cybertruck
However, back in 2020, Musk announced that the brand would be deviating from cylindrical cell batteries for the first time, introducing a Lithium Iron Phosphate (LFP) prismatic-type battery that would be used in some Model 3 and Model Y Teslas. These vehicles were made available from 2022 onwards, and owners can check if their vehicle has this battery type via their dashboard touchscreen:
Controls > Software > Additional Vehicle Information
If your vehicle is equipped with an LFP battery, you will see “High Voltage Battery type: Lithium Iron Phosphate” on the display. If your vehicle does not have an LFP battery, then no battery type will appear.
All other Tesla vehicles feature cylindrical-type battery packs. Depending on the vehicle model and where and when it was produced, this will either be a 18650-type battery, a 2170-type battery, or the most recent 4680-type battery.
The brand new 4680 cylindrical battery cells are so far only being placed in vehicles manufactured in the Gigafactories in Texas and Germany, where they are currently being made in-house by Tesla. However, collaborative mass production with Panasonic is set to begin in 2023, so there will be more of these novel battery packs to go around soon.
Why Does tesla Use Cylindrical Battery Cells?
Tesla uses cylindrical battery cells because of the advantages offered by the cylindrical shape of the casing. The shape allows for the internal electrodes to be wound evenly, which reduces the impact of mechanical vibrations and damage through thermal cycling. The shape also prevents undesired swelling, which can occur when gases accumulate within a battery’s casing.
The advantages of cylindrical cells are therefore:
- Vibration resistance
- Thermal resistance
- Swelling resistance
- Performance loss resistance
- Extensive quality control track record
- High energy efficiency
Because the design and application of cylindrical cells had been honed through years of use before Tesla developed their own 18650-type battery pack, the brand was also able to keep production speedy and costs low.
Panasonic has been manufacturing cylindrical cells for Tesla since its inception, although the most recent 4680-type cylindrical battery cell is currently being manufactured in-house by Tesla, with Panasonic set to jump into further production in late 2023.
|NCA or NCM Cylindrical
|Tesla (Panasonic planned)
What Is the Future For Battery Cells in EVs?
It remains unclear which battery type, if any, will dominate in the long run.
Just as Tesla’s first Prismatic-type battery cell was hitting the road in 2022 Model 3 and Model Y vehicles, German luxury car maker BMW announced that they will be switching from prismatic-type cells to cylindrical cells for their future EVs. Chinese company Energy Co Ltd. will reportedly be manufacturing and supplying the Tesla-like cylindrical cells for BMW, with the first vehicles featuring this new battery type expected to hit the market in 2025.
As the world races towards carbon neutrality, we can be sure that the EV industry will continue to set the pace. This will likely involve continued evolution of the batteries that power Tesla vehicles. However, alongside operational efficiency, it is possible that the availability of the minerals required to create these batteries will dictate the road ahead. This may in fact have been a motivation behind Tesla’s LFP prismatic-type battery, which is comprised of materials that are much more readily available than those used in the NCA and NCM cylindrical battery cells.