Electric cars/trucks and grid power storage are going to be the drivers of battery tech for the foreseeable future.
Will the cells be usable in a mod? Maybe, but that hinges on Tesla making good on the battery plant and selling lots of cars. Otherwise, car makers are going to look for a more friendly size/shape for their designs. Hoards of small cylindrical cells vs custom cells that can fit here and there.
Grid storage is using various things like salt water batteries, molten metal, things that we aren't going to be able to use.
With the renewable power push, there's all sorts of battery tech coming out of the woodwork.
I'm kind of liking the 20700 and hope to see some mods that use it by year end.