As for AA batteries, they have been around since 1907 (though the size was not formally standardized until after WWII). I wouldn't be surprised if they were st

As for AA batteries, they have been around since 1907 (though the size was not formally standardized until after WWII). I wouldn't be surprised if they were still around in a few decades' time - there's simply too much cheap consumer electronics out there relying on AA for it to make sense to introduce a new standard. (Energy density is likely to keep increasing - but as for the form factor itself, I suspect it will outlive me.)