Amprius is selling high energy density batteries today for military drones. Of course longer flight no brainer. There are many Si nano particles in production.

https://medium.com/areas-producers/ev-dreams-new-ingredients-for-ev-batteries-531eb2c62f2b

This brings me to an interesting concept. What if a battery design is 10% of the cost and 10% of the weight. So $10,000 cost drops to $1000. The weight drops to 200 pounds. But the life is only 50,000 miles. So replace every 50,000 miles. Would that work with consumers?