TESLA BATTERY DAY
TERA-FORMING THE AUTOMOTIVE AND ENERGY INDUSTRIES
to sustainable energy. In 2019 the world produced just 0.006 TWh of stationary battery storage, which implies a 1,600 fold growth required in order to reach 10 TWh.
In total the world would need 20 TWh of batteries annually, which is equal to the output of roughly 570 times the batteries that Tesla will produce this year.
Tesla plans to produce 100 GWh (gigawatt-hour) of batteries in 2022 and 3 TWh by 2030. In order to realise this plan, Tesla developed a roadmap to reduce battery costs by 56% on a $/kWh basis, while increasing range by 54%.
To simplify the magnitude
announcements, not to mention its lofty ambitions, the innovations that would enable the battery cost declines and efficiency improvements are broken down into seven categories, each one as groundbreaking as the next:
Cell Design – 14% reduction in $/KWh cost
Tesla’s new 4680 battery cell is arguably the biggest breakthrough in lithium-ion battery technology since its invention nearly 50 years ago. The number 4680 represents a combination of the diameter (46 mm) and length (80 mm) of the new battery cell.
Tesla started out with a much smaller 1865 cell form factor, which is still used in the Model S/X, before introducing the 2170 cell form factor for the Model 3/Y. The bigger form factor of the 2170 cell achieved a 50% increase in energy compared to the 1865 form factor.
The new 4680 battery cell is a tab-less, dry-coated cell that adds five times more energy, 16% more range, and six times more power. This translates to a 14% reduction in $/kWh cost at the battery pack level. Elon Musk was not exaggerating when he described the new 4680 cell as “a huge deal”.
Tesla is now in the process of ramping up production of the new 4680 cell to 10 GWh per annum in its Kato Road pilot production facility in Fremont. When at full production capacity, this “pilot plant” will be the 13th largest battery factory in the world. Currently, Tesla’s Gigafactory Nevada – at 35 GWh of annual production capacity – is the largest battery factory in the world. Musk also revealed that the new 4680 cells have been used in cars since May this year.
Factory Design – 18% reduction in $/KWh cost
Tesla’s new dry coated electrode process increases speed and reduces footprint. New cell assembly lines are designed to optimise continuous movement with a seven times improvement in line output. Efficiencies gained from formation optimisation – the process of forming, charging and testing each cell – now enable Tesla to achieve a further 86% reduction in formation investment and 75% reduction in formation footprint. Combined with its new dry coated electrode manufacturing process, this leads to a 75% reduction in investment per GWh and a 10 times reduction in footprint per GWh, which is at least four times better than any existing battery manufacturing plant today, including Tesla’s Gigafactory Nevada. This translates to Tesla achieving 1 TWh of cell production in a factory that is smaller than the 150 GWh Gigafactory Nevada. All of these manufacturing improvements translate to an 18% reduction in $/KWh cost at the battery pack level.
Anode Materials – 5% reduction in $/KWh cost
Musk and Baglino revealed a revolutionary new use of silicon in the battery anode as one of the major steps towards reducing cost and increasing efficiency. While silicon can store nine times more lithium than graphite, silicon also expands four times its volume during charge/discharge cycles, which causes the silicon to deform, and become unstable over time. By stabilising the raw metallurgical silicon with Tesla’s proprietary elastic, ion-conducting polymer coating, and then integrating the silicon with the electrode using Tesla’s proprietary highly elastic binder, Tesla has managed to contain the expansion stress on the silicon particles during charge-discharge cycles. The use of raw metallurgical silicon, along with Tesla’s secret ingredient, will decrease $/KWh cost by 5% at the battery pack level, while increasing range by up to 20%.
Cathode Materials – 15% reduction in $/KWh cost
Currently, battery cell cathodes consist of any one or a combination of metals, mainly iron, manganese, cobalt, aluminium and nickel, which separately, or in combination, provides the necessary stability to store lithium ions during charge/discharge cycles. Tesla’s preferred choice is nickel because of its cheaper price and relatively high energy density and stability, and while cobalt offers even higher energy density and stability, its sustainable production is limited because of ethical mining concerns and therefore it remains subject to price fluctuations.
Tesla’s new high nickel cathode has no cobalt in it, and instead uses Tesla’s proprietary coatings to provide stability. This alone ensures a 15% reduction in cathode $/KWh cost. However, since nickel is more expensive than some of the other cathode materials, and not really necessary in all applications, Tesla is taking a horses-for-courses approach to its cathode solution across various products and models. As such Tesla plans to use iron cathodes with a long cycle life (read million mile battery) in the Model 3 Standard Range, a new smaller $25,000 model manufactured as two separate models in Europe and China respectively, as well as its grid storage Powerpacks. For long range applications – Model S/3/X/Y and residential Powerwall – Tesla will use a nickel/manganese cathode. Finally, a high nickel cathode will be used in high mass, long range applications like the Semi and Cybertuck, and more than likely in the new Plaid battery and powertrain destined for the Tesla Roadster, Model S and Model X.
More than that, and in typical Elon Musk style of applying “first principles thinking” to every engineering problem, Tesla has simplified the extraction of nickel from nickel ore to achieve a 66% reduction in capex investment and a 76% reduction in process cost, with zero waste water.