chemistr: look at CCHSC, too hard/lazy to remember
cost/prac: you tell me.... is dry cell cheap? do you see them been used everywhere?
is vanadium cell cheap (well you probably won't know, since ...) are they used everywhere? (not really)
reason for this is that vanadium redox requires large volume to store its electrolytes and cathode and anode (IIRC). this makes it quite impracticable at the moment. A professor at UNSW however, i remeber made a golf cart out of vanadium redox. that's about it
impact:
dry - you tell me. think this way, WITHOUT dry cell, what WON'T be possible?
vand - talk about potential of completely rechargable batteries i suppose... (where as dry cells are non rechargable)
environ - dry - quite minimal. although the ammonia can pose abit of environmental threat
vand - harmless (? memory failing me... did i remember this right?) since V exist in the world in significant quantity already. (not that you need to know, but some form of V are used to treat diabetes. just to prove how "toxic" they really are)