autoevolution
Car video reviews:
 
Tesla Introduces New 4680 Battery Cell, Claims 54 Percent Overall Range Boost
One of the biggest reveals - or at least the one that kickstarted all the rest - was Tesla's all-new in-house battery cell dubbed 4680. As we've come to know, those apparently random numbers tend to refer to the actual cell size, and Tesla's product makes no exception.

Tesla Introduces New 4680 Battery Cell, Claims 54 Percent Overall Range Boost

Tesla new 4680 battery cell presentationTesla new 4680 battery cell presentationTesla new 4680 battery cell presentationTesla new 4680 battery cell presentationTesla new 4680 battery cell presentationTesla new 4680 battery cell presentation
Yes, this thing is massive. With 41 millimeters in diameter (1.6 inches) and 80 mm in length (3.15 inches), it's significantly larger than the current 21700 cell used in the Model 3 and Model Y, and even more gargantuan next to the 18650 standard that was used when the Models S and X came about.

A bit of math will tell you the 4680 is almost 5.5 times larger than the 21700 in terms of volume, which is what ultimately matters most. That makes Tesla's figures for its energy capacity (5x), power delivery (6x), and range increase (16x) seem less impressive than they might have been at first sight.

However, don't be so quick to dismiss the importance of this new cell because its size is just one important element; the second one is that it uses a tab-less design. Regular cells rely on tabs to connect the anode and cathode inner layers to the exterior elements of the battery, thus limiting the flow of electrons and making heat buildup a very real issue.

The tab-less solution presented by Tesla means fewer parts, which reduces the complexity and cost of manufacturing, and also much-improved heat management. Musk said that because of the shorter electrical path in the new cell (five times shorter than in the 21700 despite the increase in size), the 4680 has a better power to weight ratio, which would indeed be a big deal.

The benefits of the tab-less design extend beyond its actual use in a vehicle. According to the Tesla CEO, this solution will make the entire manufacturing process a lot quicker. "It's a real pain in the ass to have tabs from a production standpoint," he concluded.

Tesla is also considering new materials for both the cathode and the anode of its cells. For the former, the company will focus on replacing the cobalt that's currently used with the much cheaper and readily available nickel. For the latter, the plan is to use raw metallurgical silicon (again, cheap and abundant) instead of the more complex and expensive graphite.

Finally, a further performance increase will come from the way the new battery cells will be integrated into the vehicles. Musk makes a pretty good analogy between the way early aircraft wings used to carry a fuel tank inside, and how they have become the fuel tank itself on modern airplanes. The tank isn't cargo, it's part of the structure. It IS the structure.

The idea here is to make the pack itself structural instead of relying on additional support elements inside the pack. The cell casing will become part of the battery pack's structural integrity - think of the cells as the honeycomb elements in a regular honeycomb sandwich. This will reduce the overall mass of the battery while also freeing up space inside for a more energy-dense packaging solution.

Putting all these things together, Tesla claims the new battery enables a range increase of 54 percent, a cut in cost per kWh of 56 percent, and a reduction in investment per GWh of 69 percent.

How far are we from all of this becoming the new norm? Apparently, three years or so. Three years during which a lot of things can happen, and most probably will.

First, though, Tesla has a very busy 2021 to navigate through, and if this presentation has made something perfectly clear, it's that developing the actual vehicles is just a small part of everything that goes on behind closed doors at Tesla. And this was just about batteries. Imagine if Tesla made an Autopilot Day as well.



 
 
 
 
 

Would you like AUTOEVOLUTION to send you notifications?

You will only receive our top stories