Actually CATL announced a 500 wh/kg battery a few months ago. Solid state and aimed at the aviation market. Shipping this year apparently. There are a few other companies targeting that market. For cars, much lower density sodium ion and lfp batteries are what they are producing in volume. Sodium ion especially is becoming popular for the kind of cheap/modestly priced cars Toyota is famous for mass producing.
Those higher density batteries are great when cost doesn't matter (like in the aviation market) but cost is the only variable that matters when it comes to mass producing electrical vehicles. The game is not who can build the most ridiculous car for 100K but who can produce the most useful car for 10K. Toyota is going to have their ass handed to them very soon in that market unless they get their act together.
People that obsess over range are missing a few important points. With fast charge times, range matters less, and if your car is fully charged every morning, the times when you need to charge before you get home reduce to the rare occasions when you actually drive the cars maximum range in a single day. Which for the average driver isn't that often. The point of having a large battery is reducing those occasions to almost zero. If that matters to you, just spend more money and you'll be fine. There's no need for new batteries for this.
The point of a having a smaller battery is that the few times per year that you have to stop to fast charge them isn't worth the price difference in terms of time spent. Especially when that time is basically only around 30-40 minutes. Companies that operate vehicle fleets get this. They get the battery size they need, not the largest one. That's why most electrical vans have batteries that aren't bigger than those in cars. Smaller even sometimes. Smaller battery means more useful load. The reduced range is fine.
Toyota doesn't need a new science fiction battery, it needs battery production infrastructure producing batteries by the twh per year. Nothing else is going to enable them to mass produce cars at the same rate they are producing ICE cars. They are not building those factories yet. I'm not sure what they are waiting for at this point. But they are running out of time. Cheap EVs are going to be on the market pretty soon. They already are on the market in China. The main constraint for that is battery production volume. Some companies are investing in that as fast as they can; Toyota so far isn't.