I suspect you mean Li-Mn (often represented as LiMn). [Li Min is the daughter of Mao Tse-tung (of
Little Red Book fame and a minor revolution).;-)]
Li-Ion (lithium ion) and LiMn (lithium magnesium) are two of the chemistries used in
batteries. Another is LiFePO
4 (lithium iron phosphate). I have just exhausted my technical knowledge of battery chemistry.
I do know the consequences for us vapers: LiMn and LiFePO
4 are the safer chemistries and, therefore, their
batteries don't need the PCB used on protected Li-Ion
batteries. [Never buy or use a Li-Ion battery without such protection.] Also, LiMn is the chemistry used in IMR high-drain batteries (which pack a greater punch than Li-Ion, but tend to be lesser mAh). LiFePO
4 is most often seen in RCR123A 3.0V batteries (typically used stacked in 6V mods) and is preferred over Li-Ion for that purpose, since stacking batteries adds risk.
I prefer using the IMR high-drain batteries (with LiMn) in my mods, because of that extra punch.