If you’re interested in electric vehicles, Tesla’s
Million Mile Battery
The most anticipated Battery Day announcements will revolve around the so-called “Million Mile Battery”, which as the name suggests is a battery that has a million-mile lifespan, putting an end once and for all to the misconceptions that EV batteries don’t last very long and will need a copious recycling effort. There have been several theoretical research papers released from the Tesla battery research team led by Jeff Dahn that could provide the necessary underlying technological shift. The single-crystal cathode could be significant, allowing 90% capacity after 4,000 charge-discharge cycles, where typically the figure is more like 1,000 cycles for current technology. So single-crystel cathodes would go a long way towards enabling a battery that can retain 90% capacity after a million miles, since the average Tesla battery pack can already achieve 300km without losing more than 10%.
However, another technology that would help with the arrival of the Million Mile Battery is the silicon nanowire anode, and some have argued that Tesla is teasing this with the background image for its Battery Day holding page. Silicon nanowire anodes could be a complete gamechanger, because of the massive effect they have on energy density. The technology would allow battery cells that are half the weight and take up half as much space as current lithium ion batteries, paving the way for a 400Wh/kg energy density, where the batteries in the current Tesla Model 3 have a density of around 250Wh/kg. Using these anodes, a Tesla Model 3 Long Range could have a WLTP rating of over 500 miles for the same weight. In another mysterious twist, a company called Amprius that has been developing this technology has moved right next door to Tesla, although Musk has denied any conneciton. While it’s unlikely he will be announcing silicon nanowire batteries for cars in 2021, he could well reveal a roadmap where the technology becomes available within the next 3-4 years.
Related to the Million Mile Battery was the news in June that Tesla battery supplier CATL has already announced that it can manufacture batteries with a 1.2-million-mile lifespan that can last 16 years. However, these involve a shift away from lithium ion towards lithium iron phosphate (LFP) battery technology. It’s not obvious from the name, but the key thing about LFP is that it doesn’t use cobalt, a rare earth mineral that is one of the major reasons why EV batteries are so expensive. LFP batteries have a reduced density compared to lithium ion, but are cheaper to produce and have greater durability, so an announcement of their usage would be another step towards mainstream affordability for EVs. However, the CATL technology is likely to be focused on the Chinese market initially, where the competition from local EV suppliers makes Tesla’s pricing much more important than it currently is in Europe or the USA. This battery technology may not be used in other markets just yet.
Dry Battery Electrodes
Behind this opaque technical term could be the most far-reaching announcement of the day. In May 2019, Tesla purchased Maxwell Technologies for $218 million. This appeared to be driven by Maxwell’s dry battery electrode technology, which improves production efficiency by a factor of 16 and lowers manufacturing costs by up to 20% – both key factors when taking EVs to a mass market. Maxwell’s technology has also been shown to improve battery performance, boasting a current battery density of 300kWh/kg and a roadmap to 500kWh/kg. So the acquisition of Maxwell would mean Tesla could produce cheaper batteries more quickly, and potentially with greater range in the future.
Half a year after the Maxwell acquisition, rumors began to circulate about a Roadrunner Project aimed at reducing the cost of battery production. Tesla has also purchased Hibar, which builds equipment for the production of batteries. In other words, Tesla is gearing up to produce its own batteries in great quantity, with reduced costs alongside greater density and improved density, again paving the way for more affordable EVs.
Will Tesla Become A Utility Company?
Tesla has been selling its PowerWall since 2015 and has also been dabbling in solar panels with its solar roof tiles, which currently aren’t available in the UK. It has also built vehicle-to-grid technology into the Model 3. But Tesla has also applied to be an energy provider in the UK and already acquired a license to trade electricity in Western Europe. With Tesla’s sizeable Supercharger network, it makes sense for the company to have more control over energy supply costs, particularly in tandem with expanded Powerwall sales. A large installed base of Powerwalls alongside being an energy company could allow Tesla to offer customers the ability to subscribe to a program where their house batteries sell power back to the grid at times of peak demand, via Tesla as their electricity provider. There’s lots of speculation here but joining the dots does imply directions along these lines.
Is Tesla Planning An Electric Plane?
EVs are heavy due to the weight of the batteries, but it’s not a dealbreaker of an issue for a car. However, it’s a different story for aircraft, where every gram counts. Elon Musk has discussed the possibility of a Tesla plane earlier this year after rumors that one could be in development. He denied he was working on a plane at least for the next five years, but has stated that the energy density of 400Wh/kg mentioned above is where electric planes start becoming viable. There’s unlikely to be a clear announcement about a Tesla plane at Battery Day, but there could be some hints alongside statements about reaching the magical density level.
New Manufacturing Processes in Berlin
Finally, according to Electrek, Musk is promising new painting systems and a revolution in body engineering when the Model Y starts production in Berlin. One of the developments is likely to be huge casting machines that produce car bodies in fewer, larger pieces to minimize welding, lowering production costs while speeding up manufacturing. This clearly isn’t a battery announcement, but with the Berlin Gigafactory due to start production in July 2021, it’s highly likely that Musk will announce details of progress towards this goal at the Battery Day.
Of course, there will be many more announcements on Battery Day we didn’t see coming. It’s also unlikely that any announcement will make the Tesla you just bought seem obsolete – the so-called Osborne Effect. But some very exciting developments will be revealed on September 22nd, which could further cement Tesla’s lead over its competitors.