Recently, though, lithium-ion has had some controversy. It seems that in the quest for ever-higher capacities, some manufacturers (SONY is the big one) have pushed the technology too far. Some laptops were catching fire or exploding because the batteries got too hot.
Enter lithium polymer? Perhaps... Li-po or lithium polymer batteries have been in use under pretty demanding applications such as battle-bots and radio control airplanes for a little while, and some companies are investigating them for other uses. Treehugger investigated them as did CNet news. Time will tell if these new-tech batteries can challenge other newcomers in the field like A123Systems, Altair Nanotechnologies and Firefly Technologies offerings.