Tesla shares video of 4680 Roadrunner battery line

Tesla has shared a video giving a first glimpse of the 4680 form battery revealed at Battery Day in September 2020 and its Roadrunner production line, which is expected to reduce the cost of making battery cells by 56 per cent.

In a post on Twitter, the electric car maker used the video to invite people to apply for battery manufacturing jobs at its planned battery lines in Berlin and Texas.

The 4680 battery is central to Tesla’s plan to decrease the cost of battery manufacturing. Batteries currently represent the single biggest expense in making an electric vehicle and reductions in the cost of making them are imperative to bring purchase costs in line with internal combustion engine (ICE) vehicles.

Although electric vehicles already offer big savings for owners because of the reduced maintenance and “fuel” costs, reducing battery costs to achieve purchase price parity with ICE vehicles will help to break through a major barrier to electric vehicle adoption.

Tesla currently sources batteries from several battery makers, including Panasonic, LG Chem and Chinese Amperex Technology Limited (CATL), but plans to make its own batteries using a series of strategies to increase energy density as well as reduce production costs.

Amongst these, Tesla’s new battery design will use a new winding design and tabless electrode technology that Tesla says along with other electrode production improvements will reduce $/kWh costs of making batteries by 18 per cent.

The 4680 form factor (which denotes 46mm diameter and 80mm height) maximises space in a battery pack and combines this with novel ways of using more silicon in the anode, diversifying cathodes to spread demand for materials and integrating battery packs as a structural element of the vehicle design itself. Tesla says these measures can increase range by 54% while reducing production costs by 56%.

At Battery Day in September, Tesla CEO and co-founder Elon Musk confirmed that the carmaker had been testing out a new production line, codenamed “Roadrunner” for its new battery at a facility near its Fremont electric car factory.

The video below appears to show this new production line in action, although Tesla did not clarify this in its post.

It plans to make the new batteries at its upcoming Texas gigafactory, where it will make the Cybertruck, and in Berlin, its first European gigafactory, where it will first make the Model Y.

In November, Musk said he believed the Berlin factory would become the “largest battery cell plant in the world,” although he did not clarify if this was in comparison to current battery factory sizes or other planned future factories.

As electric vehicles become more mainstream, making enough batteries to supply the growing electric vehicle market may also become a problem as demand for materials such as lithium, cobalt and nickel increases.

CATL supplies cobalt-free lithium phosphate batteries to Tesla’s Shanghai factory for its Standard Range Plus Model 3, a strategy that helps to reduce demand for cobalt.

It plans to use a high-nickel cathode in its 4680 battery to produce a more energy-dense product for use in more demanding applications such as Tesla’s planned electric Semi truck and the Cybertruck.

At Battery Day in September, Musk said the Californian carmaker estimated some 20-25 terawatt-hours of batteries per year would be needed to power enough electric vehicles and homes to mitigate climate change.