Tesla batteries could have an energy density high enough to power an electric plane by 2023, Elon Musk hinted at on Monday (US time) in a comment on social media platform, Twitter.
The comment comes just as Tesla published a web page for Tesla’s 2020 AGM, which will also encapsulate Battery Day, slated for September 22, the anticipation for which is really starting to heat up.
It is expected that Musk will reveal details about a “million-mile” battery that would mean Tesla cars could outlive combustion cars by many years, but more recent developments have Tesla watchers guessing at the possibility that Musk will reveal much more than this.
Musk has noted before that he thinks Battery Day will be “one of the most exciting days in Tesla’s history”, so it’s no wonder there is so much hype around the event.
Musk’s most recent comment, posted in response to a Twitter thread by Sam Korus of Ark Invest – a major Tesla bull – about why the clean energy and transport entrepreneur keeps hinting at a Tesla electric plane, has been spiked with talk of another possible tech development involving silicon nanowires that are being used to make batteries for drones.
It’s well known that Musk would dearly like to develop some sort of electric flight, but it appears to be on the back-burner after Musk recently admitted that with so many other projects on his plate, his “brain will overload“.
The will is strong, however. In Monday evening’s thread, Korus noted that Musk has previously said that “electric flight starts to get interesting once you hit 400wh/kg“.
Musk responded, “400 Wh/kg *with* high cycle life, produced in volume (not just a lab) is not far. Probably 3 to 4 years.
400 Wh/kg *with* high cycle life, produced in volume (not just a lab) is not far. Probably 3 to 4 years.
— Elon Musk (@elonmusk) August 24, 2020
Korus is referring to comments made by Musk in June 2019, in which he said that 400Wh/kg density would be a game changer for electric flight because although “Jet A (kerosene) has much higher energy density than Li-ion …. electric motors weigh much less & convert stored energy to motion better than combustion engines”.
FWIW, based on calcs I did 10 years ago, cross-over point for Li-ion beating kerosene is ~400 Wh/kg. High cycle batteries are just over 300 Wh/kg today, but probably exceed 400 in ~5 years.
— Elon Musk (@elonmusk) June 30, 2019
Interestingly, Musk’s latest comments come just a week after a new lithium metal battery patent was published by Tesla’s battery research team headed by Jeff Dahn, which hinted at a future Tesla battery with enough energy density for electric flight.
Which brings us to the next clue, or hint, or red herring – whatever it is, you will have to make up your own mind.
The background for the Battery Day page has pundits honing in on a theory that silicon nanowires made by a company called Amprius Technologies could also be part of Tesla’s grand plan.
This is based on the assumption that the background of the Battery Day page has the appearance of silicon nanowires, and major silicon nanowire company Amprius Technologies has an office very close to Tesla’s Kato Road facility in Fremont.
Adding fuel to the flame, Amprius Technologies’ website states that its focus is on, “Providing game-changing performance for advanced autonomous and electric vehicle applications, Amprius Technologies’ batteries provide more run time and longer endurance than any other battery technology on the market.”
In 2019, it also announced it was working with aviation giant Airbus to “drive the development of higher volume production capacity along with higher energy density cells for Airbus Defence and Space aerospace programmes.”
It’s all very scintillating. Unfortunately, we still have 28 days left to find out if Battery Day will deliver more than just a million-mile battery.
Bridie Schmidt is lead reporter for The Driven, sister site of Renew Economy. She specialises in writing about new technology and has been writing about electric vehicles for two years. She has a keen interest in the role that zero emissions transport has to play in sustainability and is co-organiser of the Northern Rivers Electric Vehicle Forum.