Battery cell

The math behind Tesla Battery Day: Revolutionizing Industry at a Million Miles an Hour

We have summarized all the math from the Tesla battery day presentation of 3 hours in a short blog article that you can finish faster than brewing your morning coffee. In summary, Tesla claims a 54% increase in range (Ex: Model S current range increasing from 400 miles to 620 miles), a 56% reduction in $/KWh (Ex: $120/KWh to ~$50/KWh), and a 69% reduction in investment per GWh via vertical integration in 3 years or less. The breakdown of the increase in range and a decrease in cost is driven by the following 5 factors:

1. Cell Design

Tesla Battery day cell design

Range Increase: 16%

Cost ($/Kwh) reduction: 14%

Investment (per Gwh) reduction: 7%

Tesla introduced a cell design featuring a 46 mm diameter and a “Tabless” architecture. It is called the 4680 Cell. This variant enables six times more power than their previous 2170 cell. The new design does away with a “tab” that connects the battery cell and extends the contact points throughout the cell without pushing all electrons through a small tab. This reduces heat and distributes power better.

2. Cell Factory

Range Increase: 0%

Cost ($/Kwh) reduction: 18%

Investment (per Gwh) reduction: 34%

The company is boosting the manufacturing of its new tabless cells in a new location. One main improvement comes in the form of the battery dry-coating process (based on Maxwell acquisition), which involves converting sand into a conductive film without using any solvent. This will simplify the overall manufacturing process.

It would take Tesla about a year to manufacture 10 terawatt-hours worth of energy per year.

3. Anode Material

Tesla Battery day anode

Range Increase: 20%

Cost ($/Kwh) reduction: 5%

Investment (per Gwh) reduction: 4%

Tesla is planning to use raw metallurgical silicon which is abundant and cheap stabilizing it with a polymer coating. Silicon stores 9x more lithium than graphite (typical anode material). This will play a significant role in increasing the overall range and cost reduction.

4. Cathode Material

Tesla Battery day cathode

Range Increase: 4%

Cost ($/Kwh) reduction: 12%

Investment (per Gwh) reduction: 16%

Tesla is leaning towards bringing its batteries down to zero percent Cobalt. They are targeting to use three different materials for the cathode design depending upon the usage criteria. Iron cathodes for low range vehicles (maximizing charging cycles), nickel-manganese for mid-range (maximizing range) and pure nickel will be used for high range vehicles (minimizing mass).

5. Cell Vehicle Integration

Tesla Battery day vehicle integration

Range Increase: 14%

Cost ($/Kwh) reduction: 7%

Investment (per Gwh) reduction: 8%

Taking inspiration from aeroplanes, Tesla will now manufacture batteries as a structural component without the need for any filler material. They will also use single-piece casting resulting in 370 fewer parts in their cars which leads to a 10% reduction in mass. Tesla already has the world’s largest casting machine that is being used for Model Y and this will be a further extension of that work.


So in summary, adding all the numbers above for the 5 factors will result in 54% increase in range, a 56% reduction in $/Kwh, and a 69% reduction in investment per GWh in the next 3 years as per the image below.

Other key points:

In 1 year: Tesla Model S plaid is launching next year with 0-60 mph in 2 seconds, top speed 200mph and range of 520 miles.

In 3 years: Tesla is planning to bring affordable $25,000 car

In 10 years: Tesla’s goal is to replace 1% of the global fleet (2 Billion) and wants to make 20 million vehicles per year (2030).

The series of innovations announced by Elon Musk has sent shockwaves around the world, especially with the $25,000 electric vehicle launching in the next three years which will make it cheaper than the regular ICE (gas) cars.

Posted By Sayan mitra

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