Part 1 1. Introduction 2. Elon's Battery Day & Other Tesla News
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Battery Day – Part 1 By John Benson September 2020 1. Introduction This post has been in the oven a long time. Originally Elon said that his “battery day” would be in April, and he would be announcing some breakthrough information. I started collecting information on his recent battery developments long before he announced this event. After Elon slipped battery day several times, I got tired of waiting and posted the paper described and linked below in late July. The earlier paper described Tesla’s battery R&D center (in Fremont near their mothership auto plant), the chemistries that Tesla is using, his long lifetime (a.k.a. “million mile”) battery developments, dry battery electrode development (via Maxwell), the magic number ($100 per kWh), and summarized developments I had announced in earlier posts. https://energycentral.com/c/gn/battery-breakthroughs Since Elon finally had Battery Day on September 22, I will post Part 1 on the 29th and cover this event and other Tesla information in Chapter 2. After chapter 2, the others (in Part 2) will cover: other (non-Tesla) battery developments, the new current largest battery energy storage system (BESS) in the world (also non-Tesla), the upcoming new largest BESS (Tesla), and finally any other recent or near future major BESS projects (mainly in California). 2. Elon’s Battery Day & Other Tesla News Elon was very lucky and very smart when he rolled out his first significant battery electric vehicle (BEV), the Model S, in that he selected Panasonic as his battery partner. They jointly built Gigafactory 1 to manufacture batteries for his BEVs and BESS. Even though production was miniscule compared to today’s, he had really big dreams and understood that lack of capacity to produce enough state-of-the-art batteries was a major potential obstacle to fulfilling those dreams. Still is. Now that Tesla is producing more than 300,000 BEVs a year, and some really, really big BESS, he needs to take the next step. Not just produce his own batteries, but produce the best BEV and BESS batteries in the world – the highest energy capacity, most powerful, lightest (for BEVs), least expensive and longest-lasting batteries in the world, and make them by the gazillions. 2.1. Tesla’s Battery Day I have collected several articles on Battery Day, and will reference them below. Each subsection below will either cover a major breakthrough Tesla has made with their new batteries or other major announcements. 2.1.1. Batteries: 4680 Cell Design The Tesla Roadster, Model S, and Model X all use individual 18650 cells--the same kind found inside one of those chuckin' cloud vapes that the young people love so much. The 1 Model 3 and Model Y received 2170 cells, which have a volume around 50 percent larger than its predecessor and also delivers nearly twice the energy density… Tesla's new cell is the 4680. Tesla claims that the cell has five times the energy stored within compared to the 2170. This means 16 percent more range over current cells and a 14 percent reduction in cost.…1 Musk and team talked next about innovations in anode design, using silicon instead of graphite because it can store nine times as much (energy?) as graphite. Although there is a lot of concern about how much lithium is required for battery production, Musk argued that it was the most abundant element in the earth’s core after oxygen. In fact, he said that just Nevada had enough lithium to convert all the cars in America to EVs. The problem with using silicon is that it doesn’t last well through multiple charge-recharge cycles due to expansion, and traditional methods to combat this are expensive. So Tesla intends to use raw metallurgic silicon instead, and stabilize the surface with an elastic ion-conduction polymer coating that can cope with expansion (see slide below). 2 This enhancement would lead to a 5% reduction per kWh – perhaps not as much as other areas, but it all adds up. …Tesla announced that it will be using more Nickel in its cathodes, eventually leading to the complete removal of cobalt. This will reduce the cost of cathodes by 15% per kWh. Tesla also plans to simplify the production process considerably, leading to a 76% reduction in process cost. This would have added benefits of using recycled water leading to no waste and enabling the use of more sustainably mined and sourced ores, with greater opportunities for recycling. 1 Rob Stumpf, MSN The Drive, “Tesla Battery Day: Musk Promises Double the Range from New Design and a $25,000 EV”, Sep 21, 2020, https://www.msn.com/en-us/autos/enthusiasts/tesla-battery-day-musk- promises-double-the-range-from-new-design-and-a-dollar25000-ev/ar-BB19jHmQ 2 James Morris, Forbes, “Tesla Reveals Plan To Halve EV Battery Costs At Battery Day 2020”, Sep 22, 2020, https://www.forbes.com/sites/jamesmorris/2020/09/22/tesla-reveals-plan-to-halve-ev-battery-costs- at-battery-day-2020/#76c132a37f74 2 Elon Musk recently clarified that Tesla’s new 4680 cells are already being deployed in some of its vehicles as prototypes. Even more interesting is that the next-generation batteries have already been in use for several months, though the CEO did not state which of its vehicles are equipped with the 4680 Roadrunner batteries.3 The Tesla CEO related his update in a recent post on Twitter. While responding to a question about the company’s strategy with its cathodes and its suppliers, Musk noted that Tesla’s own battery cells are already powering some of its cars. That being said, Musk clarified that ultimately, prototypes such as cars that currently run on the company’s 4680 cells are trivial, as they are incomparably simpler than actual volume production. “We’re only doing high energy nickel ourselves, at least for now. Also, maybe the presentation wasn’t clear that we’ve actually had our cells in packs driving cars for several months. Prototypes are trivial, volume production is hard,” Musk wrote. Interestingly enough, Elon Musk noted that Tesla is only producing cells that feature high-energy nickel cathodes for now. During Battery Day, Tesla’s slide outlining its cathode strategy listed the Semi and the Cybertruck as vehicles that will be using high- energy nickel. However, the CEO did not confirm if the Cybertruck prototype or the twin Semis doing road tests across the United States are now equipped with 4680 cells. Such a scenario seems plausible as both vehicles only have prototypes today. Using 4680 cells for the Cybertruck and the Semi would be strategic for Tesla, especially since both are heavy-duty machines that are designed to be as tough as possible. The Cybertruck is quite literally created to topple the kings of the pickup market, and the Semi is designed to disrupt the long-haul segment, which is known for its consistent, heavy demands for its vehicles. Needless to say, Tesla’s mettle as an automaker will be 3 Simon Alvarez, Teslarati, “Tesla’s new 4680 battery cells have been deployed in working vehicles for months”, Sep 27, 2020, https://www.teslarati.com/tesla-deploys-4680-cells-roadrunner-batteries/ 3 put to the test by the Cybertruck and Semi, and their 4680 high-nickel cells could be their trump card against the competition. That being said, the first vehicle that would likely be released with Tesla’s 4680 cells will be the Model S Plaid, which was announced on Battery Day… (See section 2.1.6). 2.1.2. Structure Improvements Presently, Tesla already stows the batteries away in the floor of the car, however, Musk compares this akin to luggage. Tesla will use its new casting process to integrate battery rigidity into the car's structural support, strengthening it even further than a modern floor- mounted battery pack. The cells can be packed even closer to the center of the vehicle, improving vehicle handling, range opportunity, as well as decreasing overall mass and parts complexity.1 With the changes to storage, increase efficiency in cells, and overall packaging of the battery, Tesla believes that the new changes enable up to a 54 percent increase in vehicle range. That would be a massive, massive jump from a company that already has the longest range EVs in the business. “The non-cell portion of the battery has negative mass,” Musk said. “We saved more mass in the rest of the vehicle than in the non-cell portion of the battery. So how do you really minimize the mass of the battery? Make it negative.”4 The minimization of mass allowed the automaker to increase the density of the battery pack. Individual cells could be positioned more efficiently because excessive structures within the pack itself were eradicated. The new Tesla battery design … improves pack density along with structural integrity. Additionally, the filler within the Model 3 and Model Y packs, which currently uses a flame retardant, now uses a structural adhesive and flame retardant. This adhesive effectively attaches the cells to the top and bottom sheets of the pack. “This allows you 4 Joey Klender, Teslarati, “Tesla outlines new casting and battery architecture, future of EV designs”, Sep 23, 2020, https://www.teslarati.com/tesla-casting-battery-architecture-ev-designs/ 4 to do sheer transfer between the upper and lower sheet,” which increases stiffness and prevents major deformation in the event of a crash. Improvements in the casting design of Tesla’s future cars and the newly designed battery architecture, which uses new materials and strategies to increase stiffness, will increase the already safe vehicles that the company manufactures.