Tesla’s Latest Battery Improvements From Battery Day 2020 — “Tera Is The New Giga”
Tesla has made a revelation about their improved battery design on “Battery Day” last September 22, 2020. The event was originally supposed to launch earlier in the summer, but there were cancelations. This time, Tesla was ready and prepared to present what exactly they are trying to accomplish with a new battery design. This was also a shareholder’s meeting, so the expectations were high about what to expect. If you have heard about the tabless electrode battery, that is just one part of the plan.
There were many insights from the presentation that focused on the engineering and manufacturing aspects of Tesla’s new battery architecture and how it will affect EV (Electric Vehicles). I will discuss some of the takeaways or good points made in the presentation. It was for the most part, not everything that I expected, but not in a bad way (I will explain that later). The presentation was held outdoors, in line with CDC guidelines for social gatherings that allow more physical distancing. It was like a drive-in meeting though since attendees were in their cars while Elon Musk and his engineers were presenting on a stage. There was plenty to honk about!
New Battery Architecture
A new battery architecture was presented with a tabless electrode design. This solves thermal issues in the battery (i.e. ohmic resistance), allowing more efficiency in operation. It also allows the move to a lower cost form factor and a simpler manufacturing process with the new design. This lowers the cost per kiloWatt hour (kWh) in half, according to Tesla.
In the new design, there is a shorter path link in a large tabless cell (4680 Cell). The shorter path helps to reduce heat in the battery. The distance for electrons to travel is also less since they no longer have to travel the entire length of the electrode, but rather only the height of the electrode. The new form factor allows larger cell size with higher energy density cells to provide power. This significantly affects the battery’s range. The most important thing about this is it allows EV to travel longer distances, with a higher energy density battery.
A higher energy density allows more energy to be stored in the battery. Another part of the redesign to achieve this would be to change the material used in the battery. This requires changing the cathode material from Cobalt to Nickel or High Nickel. This alters the supply chain for sourcing materials for the battery, but also lowers the cost. Cobalt is more expensive because it is difficult to extract. It is also considered a conflict mineral, mined in regions of instability where human rights are violated by companies involved in the supply chain. Nickel, on the other hand, is more abundant and cheaper thus providing an economic incentive over Cobalt.
Another part of the redesign involves the battery’s anode. The new cell’s other purpose is minimize or tolerate wear and tear on the anode. This uses a raw metallurgical silicon material and coating it with advanced materials that increases its resilience. As part of the anode, it is integrated with an ion conducting polymer. This shaves off more costs, at 5% reduction per kWh or around $1.20/kWh.
The challenge for Tesla manufacturing large cells was with thermal issues and supercharging. There must also be a balance between reducing the cost and increasing the range. The solution was finding the sweet spot in the form factor size of the cylindrical diameter which was 46 mm and a length of 80 mm. This delivers 5x the energy with a +16% increase in range and provides 6x the power. The change in form factor also leads to a 14% $/kWh (dollar per kWh) reduction.
Tesla is also addressing a problem faced in battery factories. They cannot scale quickly enough to meet the demands for mass production of EV. According to Elon Musk (From the Tesla Battery Day Event) they would need to build 135 Gigafactories to make 20 Terawatt-hours (TWh) of batteries a year to meet production goals. That is not quite realistic, so there is another approach. They would need this for a 30–40% expansion from 2020 and forward to build EV. The solution is to build Terafactories.
The presentation made it clear that Tesla intends to ramp up production of their battery. They have already started this at their existing pilot 10 GWh facility. The plan is to cut the cost per KWh in half with the new battery architecture which would allow Tesla to manufacture more affordable EV in the $25,000 price range. That could go even further down, as it competes with popular automakers like Toyota, Honda and Ford. This could disrupt the market and bring more adoption for EV.
As EV costs go down to $100/kWh, that is when they are at the same price level as the standard internal combustion engine cars. To bring costs down would mean mass production levels that would require up to 100 GWh by 2022. The goal is to reach 3 TWh per year by 2030. This will require using Tesla’s advantage in vertical integration, as they try to meet the target in production.
Cell Vehicle Integration
Perhaps the most radical idea in the battery redesign is its integration with the vehicle. Rather than the modular battery approach, the new design will integrate the battery with the car. An analogy was made during the presentation with how an airplane’s wing integrates a fuel tank for energy storage. With the new Tesla design, the front and rear of the car will be built as a single piece using the battery cells as a structural component.
The battery packs will now be built into the EV. By integrating the battery with the body, it saves more mass and can provide more safety. The cells are moved closer to the center of the car, avoiding damage from side collisions. The integration aims to provide volumetric efficiency that provides a stiffer body, which means it will have less crumpling and damage from collisions. The design will use fillers to act as a structural adhesive that also functions as a flame retardant for the battery.
The integration brings 10% mass reduction, 14% range increase opportunity and 370 fewer parts. These help to cut off even more costs in production, that helps to bring the final price of an EV further down. Going deeper into this topic is very exhaustive, but the main point of integration is to cut on the number of parts in manufacturing, lowering cost and increasing safety.
Better For The Environment
Tesla is already involved in a battery recycling system. With their expansion, more EV will be produced. Old batteries will have to be replaced or recycled eventually. While Battery Day was mostly about the battery architecture and production cost savings, it actually is better for the environment.
The efficiency the redesign introduces to manufacturing can cut power consumption, which can reduce the need for the grid. Tesla is reducing certain steps in the manufacturing process to cut costs, thus also reducing the amount of electricity consumed by each process removed. This requires less emission from any fossil fuel source.
The disuse of Cobalt from the battery should also be significant to the environment. Cobalt not only is a conflict mineral, it can also be harmful to the health of workers who process it and negatively affects the environment in places they are extracted from (e.g. landscape destruction, pollution, etc.).
Tesla aims to be the best in manufacturing with the new processes explained. Vertical integration with automation in manufacturing will be crucial in producing batteries for mass producing millions of EV. A redesign in the battery was necessary to simplify the manufacturing process and bring costs down for car buyers to consider an EV. Another benefit is the higher capacity energy storage the battery will provide. This helps to increase the range and with less charging. One particular line of EV that will benefit from this are the Cybertruck and self-driving electric Semi trucks.
What was not discussed, and I was hoping for, was the “Million Mile Battery”. Perhaps Tesla is not quite there yet, and probably the reason for early cancelations of Battery Day. I thought this event was also more for a technical mindset and not for your average auto enthusiast. Part of my mind was also expecting to see some live demo of the battery in action, which would surely have convinced more people about the technology. If one new feature allows 2 minute supercharging, that would surely blow everyone’s mind. Overall, I like the challenges Tesla brings to the table and the solutions they have to offer.
The innovations from Tesla are ahead of the curve. The auto industry will now have to follow Tesla, unless they can come up with better innovations in battery design. There was plenty of interest in how this will affect the production of EV, and it looks like making them more affordable can create a bigger market. Not just for the budget conscious, but serious car buyers. One other thing to note is the environmental impact. It can also help meet strict standards for emissions in certain countries that are phasing out gasoline vehicles. If they can deliver on the expectations, then surely Tesla’s stocks are not overvalued.
The battery breakthrough, in my opinion could be the game changer that Tesla has been waiting for. Tesla are now pushing production capacity from Gigawatt to Terawatt levels. Their goal is to produce 20 Million vehicles a year which brings the cost of their basic EV down to $25,000. This makes it more competitive with common auto brands in mid-range or economy class market. At a more affordable price range and the fact that EV removes factoring gasoline and maintenance costs, would become a viable option for car buyers.