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More powerful and cheaper batteries – Not just for Tesla, but for ebikes too?

Elon Musk wants to reduce battery costs by over 50% – that’s one of the key takeaways from the Tesla Battery Day 2020. Given that our beloved ebikes and Teslas alike have all been powered by the same type of battery cells until now, the announcement of the new 4680 cells made us prick up our ears. Will our ebike batteries, and in turn our future ebike purchases, become more affordable and more powerful?

Elon Musk during the Annual Shareholder Meeting and Battery Day on 22.09.2020

Elon Musk announces a new generation of battery cells

Battery manufacturing costs are high and currently contribute significantly to overall vehicle costs. During the three-hour live broadcast of Tesla’s Annual Shareholder Meeting and Battery Day on YouTube, Elon Musk announced a new generation of cells that will be used in future Teslas and are intended to lower the barrier for entry into electric mobility. We explain how Musk wants to make this reduction in costs possible:

1. New cell design = 14% cost reduction

Larger battery cells are claimed to reduce cost per kilowatt-hour by roughly 14%

Up until now, the battery cells used in our ebikes have been 1865 (also 18650) or 2170 (also 21700) cells, which have a cylindrical shape. The number designates the size of the cell. For example, the 18 refers to the diameter and the 65 to the height, both in mm. The 2170 cells, which have been in commercial use since 2017, as well as the older 1865 cells, are the same as those currently found in Tesla vehicles.

Advantages of the 4680 cell:
– 16% more range
– 5 x more energy capacity
– 6 x more power

The new 4680 cell announced by Elon Musk has a diameter of 46 mm and a height of 80 mm. That makes it significantly larger than traditional battery cells. The new design is to be manufactured at the new Tesla factory in Brandenburg.

This graph shows the relationship between the size of the cell and the reduction in costs

The traditional (1865 and 2170) have a tab design, meaning that the electrons powering the circuit have a relatively long path to flow through

The new 4680 Tesla cells use a tabless design, not only shortening the path the electrons have to travel but also consisting of less individual parts, making them easier to manufacture. The cells aren’t yet production ready and Tesla is in the midst of testing them.

2. New battery factory = 18% cost reduction

There’s to be a further 18% cost reduction in the optimisation of the manufacturing (electrode, winding, assembly) of the cells.

3. New materials in the anode = 5% cost reduction

Rather than the graphite that’s been used up until now, the anode will now be constructed from silicon, further lowering costs.

4. New materials in the cathode = 12% cost reduction

Tesla have developed a new cathode manufactured completely without expensive cobalt, the mining of which often has ethical concerns. They are transitioning to a high-nickel content cathode instead.

5. Integration of the battery into the car chassis = 7% cost reduction

In the future, Tesla want to integrate battery cells as an integral structural element in the base of their cars. That should result in a vehicle weight reduction of 10% with a possible range extension of up to 14%, as well as a reduction in the number of parts.

Conclusion:

We’re convinced that the grandiose announcements of the visionary Elon Musk regarding more powerful and simultaneously cheaper battery cells will become reality. That might also have implications for ebikes – even if there is a bit of a delay. The idea to use the battery as an integral part of the chassis and to reduce vehicle weight, as well as increase range, could easily be a feature of future urban ebikes were it not for the practical issue of removing the battery. The innovations announced in terms of the electrode materials and optimised production methods may even find applications in the traditional 1860 and 2170 cell sizes and improve and reduce their cost. As of yet, it’s unclear whether the new 4680 cells will find use on ebikes due to their size.

You can find more information about ebike batteries, their manufacture, durability and environmental impact here.


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Words: Manne Schmitt Photos: Tesla