Sadly, after doing a bit of online research, this company seems sketchy as hell to me.
My first bad impression was from their their own promo video on youtube. It's slick, but they're trying to imitate Apple-style announcement videos, and not the good kind where Apple goes at least skin-deep on some technical advance they're proud of having pulled off. This one is just all gloss. Not one word as to what their battery chemistry is.
And then I went searching for online commentary, and found that in a Reddit thread, people did some digging and could not find any evidence that Donut Lab has ever filed battery patents, or employs people with expertise in developing batteries. (I have not verified these claims.)
Furthermore, the company has only been around a year or so. Established players have been researching solid state batteries for many years without achieving commercially viable results, yet here is this tiny startup promising essentially perfect results - super high cycle count, super high charge rate, incredible energy density, near zero safety hazards, perfect and cheap materials choices (though they won't say what, just that everything's basically perfect), low price, and more. No matter what the metric, they're claiming they "designed" the battery to be great at it. That gets my spidey sense tingling; if it was possible to simply decide to design a perfect battery, and do it in about a year, other companies would have done it long ago.
So, count me in the skeptic camp. I'll believe it when it's actually for sale and independent reviewers get enough hands on time with the battery cells (not the EV motorcycle that's supposedly their launch product, but just the cells) to validate some of their fantastic performance claims.
(P.S. Another thing that smells a bit funny is the product (apparently real) the company's named for, a donut shaped hubless wheel motor. These are great for visual flair - everyone loves the look of a hubless wheel - but are always terrible in practice. Among other issues, making the motor part of the wheel greatly increases the unsprung weight of the vehicle, which is awful for handling and ride quality. So, while they're using this motor as a way to establish their EV street cred, it's not actually a good EV motor... and also, developing a motor is a totally different (and much easier) task than developing a brand new battery chemistry.)