Additionally, the power electronics have improved a lot, too, and continue improving.
As others have noted, Tesla went from their induction motors (which use no rare earths) to a somewhat more efficient combination of switched reluctance and brushless DC motor using some rare earth magnets.
There are also various improvements to rare earth magnets. Magnetic energy density improves somewhat. Cooling schemes improve. Even alternatives to rare earth magnets (certain phases of iron or nickel, for instance) have been and are studied.
I think improvements in cooling schemes is a big part of future improvements. As well as reduction in eddy current losses through better litz wire, maybe playing with the grain structure of the conductor, etc.
Longer term, there's also the possibility of superconducting motors. Although that's mostly for larger scale applications, (near-)room temperature superconductors also have been demonstrated and folks are searching for methods to allow them to work at lower pressures.
So I think there's actually lot of room for improvements beyond low effort prototypes from big automakers. Tesla is doing really well with high efficiency powertrains. There's also the added dimension of integration with reduction gearing (as electric motors like to spin fast).
I know that hating on Tesla is a thing, but don't forget the higher torque, better efficiency, lower heat generation in the stator windings. And the fact that this type of motor first showed up in the Prius and Tesla made a better version of it. Yeah they're getting away with saying they invented it Prius were touting their continuously variable transmission instead of thier motors.
Toyota could've gone all-in on pure electric cars (and better plug-in hybrids than they had at the time) a good decade ago but instead they continue to waste money on hydrogen.... Only now finally announcing pure-electric cars in the US: https://www.theverge.com/2021/2/10/22187113/toyota-electric-...
It's really sad. It's really bad for the climate that they just sat on the Prius drivetrain, which is 95% of the way to a pure electric car, for over two decades (it was released in 1997... it's 2021 right now!).
Literally, people have modded (i.e. added extra battery capacity) Priuses from 2003 to be pure electric even at highway speeds with the same motor and controller. They had everything sitting right there. It's incredibly frustrating.
Toyota sold 100k Priuses it's first year (2005), and peaked at 237k Priuses in 2012. At that time, nobody had the capacity (nor the materials), to produce that many battery packs for full EV use. In hind sight, they could have committed fully to LiIon batteries for the future, but in early 2000s, it wasn't clear at all what technology would actually win. The contenders were, as I recall, hydrogen, rechargeable batteries, and bio-fuels. Toyota had concept vehicles for each of those, and the hybrid-electric was the practical compromise at the time. Toyota, being a large scale manufacturer, could not design a car around a critical component which were in short supply, like LiIon batteries.
Tesla decided to go the rechargeable route, invested heavily in battery manufacturing, and bet on LiIon analog of Moore's Law. Since they weren't going to sell 100k vehicles any time soon, they could scale along the way. Tesla didn't deliver 200k vehicles until 2018. (On a side note, Tesla also had Elon leading it. All of his 'crazy ventures' lead to colonizing Mars. What kind of a vehicle would be most practical on Mars? Not gasoline. Not hydrogen. Yep, EV. And what internet technology is the most practical on Mars? Yep, satellite constellations. What transport technology is the most practical on Mars? Underground tunnels. And so on.)
Currently, all the automakers except Tesla are scrambling to secure battery capacity. Tesla is in a very nice position right now.
Turned out, solid state batteries are much harder to mass-produce than they thought. Supposedly they will have prototype this year.
Counterpoint: that flamethrower, which probably won't be of much use in a thin atmosphere lacking oxygen.
DogeCoin FTW!
It's not Toyota's fault, it's a government mandate in Japan. That's why the CEO of Toyota has bashed full EVs in public and why Toyota is the only manufacturer actually pushing fuel cell vehicles instead of going all-in on EVs like everyone else.
From Japan: Strategic Hydrogen Roadmap [0]
> Japan’s Prime Minister, Yoshihide Suga, recently announced that Japan will aim to achieve net zero greenhouse gas emissions by 2050. To decarbonise its economy, Japan is increasingly looking to future fuels such as hydrogen and innovative technology.
> Japan’s Hydrogen Roadmap has an ambitious goal of: > 40,000 fuel cell vehicles by 2020; 200,000 fuel cell vehicles by 2025; and 800,000 by 2030; > 320 hydrogen refuelling stations by 2025; and 900 by 2030; and > 1,200 fuel cell buses by 2030.
> In Japan there are currently: > 3,800 fuel cell vehicles; > 135 hydrogen refuelling stations; > 91 fuel cell buses; and > 250 fuel cell forklifts.
Basically Japan's problem is two-fold. Their electric network is a 100V system, split to 50Hz and 60Hz sections because of historical reasons. There's no realistic way to build a charging network for electric cars in Japan.
The second part of the problem is that Japan is also heavily reliant on imported coal and natural gas for its electricity production[1] (around 60-70%).
They're betting on Hydrogen fuel cells, because that is the one thing they can produce themselves and not rely on other countries so heavily.
[0] https://www.mfat.govt.nz/en/trade/mfat-market-reports/market... [1] https://en.wikipedia.org/wiki/Electricity_sector_in_Japan
Supposedly Tesla's early cars used off the shelf lithium ion laptop battery cells to get around these patent issues.
https://en.wikipedia.org/wiki/Patent_encumbrance_of_large_au...
Probably the biggest gains going forward will be around improving the ratio of power output to weight, and reducing manufacturing costs (of both the motor and the controller). Maybe also increasing maximum RPM and improving durability, for whatever application where current motors aren't good enough.
It might also be nice to have more standardization and modularity. In the EV conversion world, there's kind of a defacto standard of motors made specifically for conversion mostly using a B-face with a 1 1/8th inch shaft with a quarter inch key slot. That helps a lot, as you can buy a motor from one company and a transmission adapter plate and coupler from another company and have pretty good odds it'll work. There are apparently ways to get almost any motor to work with almost any transmission, but that usually requires custom fabrication. (Obviously you can also ditch the transmission and just connect the motor directly to the drive shaft or transaxle or whatever. I don't know much about that route.)
I'm currently doing a conversion that uses a Netgain Hyper9 [1]. They cost about four and a half thousand dollars (including controller) and they're pretty bulky and heavy. They're really efficient though. An OEM manufacturer I'm sure could have a motor made much more cheaply and design it to run at a much higher voltage and produce correspondingly more power. I think the Hyper9 just uses magnetized iron or something like that for the permanent magnets. No rare-earths, so it might be pretty cheap to make something like that in volume. They serve the conversion market though, so it's kind of niche product. I have no idea what Nissan spends to make something like a Leaf motor.