Yes and No, Depending on your application. Individual Li-ion cells do come in AA size usually the 14500. The problem is that these batteries,although the same size as AA, are rated at 3.6 volts compared to alkaline cells(1.5v) and Nimh cells(1.2v) So the answer would be yes if you have a regulated drive that would convert the voltage coming in from battery/s to the led. You also want to be cautious when dealing with Li-ion batteries. I would recommend you as to do a little further searching on the safeties that pertain to Li-ion batteries. Hope this helped.
Gammaray