I love the smell.....
Seriously though? Sledgehammers only work when it is bitter cold and the ice can fracture easily, otherwise you just get a small circle of crushed ice right under the impact point. Oh, you also get ice-schrapnel, so be careful!
The best I found was using a metal spade. Scrape and get under whatever you can, scrape what you can off the top, and then come back. If it is above freezing, more will have softened/melted and you can get more off, if not, then use salt/de-icers. (BTW, Calcium Chloride flakes have not worked too well here. Rock salt worked better. I will have to look at some of the others later).
The only other thing that might work would be hot water. But I would use it to try and break the bond with the driveway NOT to melt or crack the ice itself. Pour a bit on the outer edge and see if that can get you under the ice to pry it up.
The only other thing I can think of would be to get some dark material like ashes or charcoal and spread that on the surface. If you get any light on it, it should melt it right down.....