the "E2" comes in both a lithium and a "titanium"
the terms are cross used E2 lithium, and L91
here is a definitive source http://data.energizer.com/PDFs/l91.pdf
there they call the E2 lithium a L91.
they do not call other E2 "technology" batteries L91 , i belive it is exclusive to the lithium battery
(edited in) oh there is also a E2 alkaline, i shoulda known.
VidPro is right, L91 is the name given to a 1.7 volt lithium AA in a standard. If you specify L91 in the USA you will get an odd face, an L91 in Europe you will get the same cell that you get hear (different brand maybe), but L91 is a standard.
