Sep 25, 2020
Tesla to eliminate cobalt from electric vehicles
2 MIN READ
At Tesla’s live-streamed Battery Technology Day this week, chief executive Elon Musk outlined the company’s plans to build a US$25,000 electric vehicle (EV) with a cheaper, more powerful battery that doesn’t contain cobalt, and the construction of a new cathode plant.
The new battery technology, which the company plans to manufacture in-house, will lower the cost of its EVs and extend their range by 16% thanks to a six-fold increase in power.
Musk didn’t provide details on the exact cost per kilowatt-hour (kWh), a key metric used to measure the performance of an EV’s battery pack. However, changes to battery chemistry and how the battery pack is made, he said, will reduce the costs per kWh by 56%, suggesting a cost below the US$100 per kWh threshold that is generally accepted for EVs to be price competitive with gasoline-powered cars.
New battery chemistry
Production of the new battery cell, called “4680-cell” because of its 46 millimetres diameter and 80 millimetres height, has already commenced with ten gigawatt-hours (GWh) of annual capacity expected before the end of 2021.
According to Energy Research & Consultancy firm Wood Mackenzie, the new design can cause thermal and rapid charging issues. However, Tesla claims to have overcome these issues by removing the tabs that act as the positive and negative connection points between the anode and cathode and the battery casing.
The tab-less design will reduce the cell’s winding and increase production rates and could result in around 20% less copper and aluminum content in the cell, said analysts at BMO Capital Markets.
The tab-less design, Wood Mackenzie noted, is yet to appear in any other commercialized EV battery cell.
Tesla also intends to eliminate cobalt in battery cathodes by switching to batteries that use less costly metals such as nickel and manganese.
In recent years, battery manufacturers have been focussed on cathode design, particularly the ratio of nickel, cobalt, and manganese used in cathodes. Manufacturers, including Tesla, are moving towards high-nickel cathodes with lower cobalt content.
But this has proved challenging because cobalt stabilizes the battery during recharging, extending the battery’s life.
To get around this, Musk referred to the use of “novel coating and dopants,” but did not provide any further details. This lack of clarification, said Woods Mackenzie, would appear to suggest that the problem has not yet been solved.
Tesla also noted that the nickel-rich cathodes would be reserved for their high-performance and commercial EVs, while lithium-iron-phosphate batteries will be used in cheaper models.
The company aims to reach 100 GWh of in-house lithium-ion battery cell production capacity by 2022 and 3,000 GWh by 2030, which, Woods Mackenzie noted, is far greater than any other major battery manufacturer has announced.
Although the outlook for cobalt and nickel remains favourable, according to BMO, the switch to cathodes with higher nickel and lower cobalt content could lead to a minor short-term reduction in forecast cobalt demand, which becomes more noticeable further out as the technology is more widely adopted.
However, BMO believes that the cobalt market will tighten going into 2021 and forecasts a 2,000 tonne per day increase to 56,000 tonnes per day in nickel consumption for 2020, with a forecast consumption by 2025 of 351,000 tonnes nickel, up from 322,000 tonnes in its previous forecast.
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