During a recent earning call of the 4Q 2019, Tesla, CEO Elon Musk, shared some details about the company's progress in the development of Tesla batteries. He emphasized that Tesla’s acquisition of Maxwell Technologies is an “important piece of the puzzle” for a company that meets the demand for the “bad-ass futuristic” Cybertruck and continuing a ramp up of electric vehicle production.
"Battery Day people. Wait until Battery Day. It's gonna blow your mind. It blows my mind, and I know it!" said Elon Musk.
Battery manufacturing is fundamental to the production of more electric vehicles. “The thing we’re going to be focused on is increasing the battery production capacity because that’s very fundamental. Cause if you don’t improve battery production capacity, then you end up just shifting unit volume from one part to another, and you haven’t actually produced more electric vehicles," Musk said.
At the moment, Tesla has the best powertrain. “It’s worth noting that the Model S has like a 100 kWh pack, the Taycan has like a 95 kWh pack. The Model S is steadily approaching 400 miles of range. The Taycan has 200 miles of range. So we must be using that energy pretty efficiently, and the powertrain is a big part of that,” Musk said.
The company is also constantly thinking about how to reduce powertrain costs. The technology developed by Maxwell will help achieve the goals set by the company.
From a source familiar with this issue, it became known that the new Tesla battery will have at least 30% more capacity and will be several times cheaper to manufacture. The production process will be extremely efficient and will significantly save on capital costs for equipment. In this scenario, a 130kWh pack seems possible. It also became known that the new cell will have a diameter of approximately 1.57 inches. The new battery will have a different form factor, so most likely it will be used for Semi and/or Cybertruck.
It sounds incredibly attractive, if this information is true, then this will be a real revolution in the world of rechargeable batteries and this will enable Tesla to be several more years ahead of other manufacturers.
Let's try to figure out how much this information can correspond to reality. Youtuber Run The Numbers in his video, explains the ins and outs of the production of battery cells and talks about the technology patented by Maxwell.
At the moment, the additive method is used to produce batteries. The components of the batteries are mixed using an adhesive additive. This makes the mixture liquid or pasty. In order to get rid of excess fluid, furnaces are used in the production, and the process itself takes a long time.
The next negative factor is that this additive is toxic, and when the substance is dried, a lot of toxic fumes are produced. In order to remove them, it is necessary to use expensive air purification systems, which in the process also collect these toxic fumes, for reuse.
Another factor is that these additives negatively affect the battery, increasing its temperature, reducing its efficiency and reducing its service life.
In 2012, Maxwell filed the patent 'Battery with the recyclable dry particle based electrode' and in 2013 it was published. The patent discloses a technology that no longer requires the addition of a liquid additive.
According to this technology, a polymer must be added as a binder additive. This is a dry substance, that is, many problems are immediately solved. Now you do not need expensive furnaces, air purification systems and a long waiting time for drying. In fact, you just have dry materials that mix in just a few minutes.
The goal is to convert the polymer into a binder that will create a film around the activated carbon. This is achieved by grinding the components of the mixture, for example by a jet mill, in this way a binder occurs at the molecular level. The patent lists other methods that can help to achieve the goal, but their essence is the same.
The patent also mentions that the mixing and fibration processes can be combined into one, this will further reduce the cost of production.
Battery cells produced in this way will enable them to accumulate more energy in themselves per second or to accumulate the same amount of energy, but in less time. That is, this directly affects the speed of charging the car. Also, thanks to this production method, the battery components are arranged in such a way that the resistance inside the cells is reduced and less heat is produced, and this makes the electrolyte in the battery more stable.
That is, in such battery cells there is more power, more energy storage, it has a higher charging speed and faster manufacturing speed, as well as much cheaper production.
Maxwell has been working on this technology for more than 6 years, trying to improve it, perhaps this is what Musk talking about "It's gonna blow your mind."