Also the internal resistance of Li-Ion batteries are lower than that of NiCad, NiMH, and lead acids already. You can get pretty rapid discharge from a raw cell, and most have some internal circuitry to prevent that from occuring.
This new battery sounds closer to the ultra capacitors that came out a few years back. Perhaps they'll have a better future.
Oh, I think they will be a boon; thats for certain.
But the danger I worry about revolves around the very low effective series resistance of the battery. Presently, if a cell phone battery internally shorts and catestrophically fails; the heat will burn your skin. One does not have to search very hard to find cases in which people have been hospitalized with 1st, 2nd or 3rd degree burns. Skin grafts are not rare in these cases.
But, now with the 'new' batteries; the energy released in the exothermic event is now released much, much quicker. So, instead of carrying an incendary device on your belt; you may be carrying a small hand gernade.
That is what I was trying to say in eloquent terms. If the energy is released slowly, you get burned. If the energy is released quickly, the cell phone/battery will explode. Same release of energy, the difference is the rate at which it is released; which goes back to my statement regarding the battery's internal effective resistance.
Or to say it another way; a 1800 mah rated battery contains the same amount of energy, without regard to being Ni-cad, Li-on, or other chemical makeup. If the battery charges quickly, it's effective series resistance HAS to be low. (The ESR current limits the charge/discharge rate) If it has a low ESR (effective series resistance), it can also discharge very rapidly. If you burn a tablespoon of gasoline, you will get a quantifiable amount of energy from the combustion. IF you vaporize the gasoline before igniting it, the same amount of energy is released, but when it detonates it will release the energy much quicker. Sometimes fast isn't good.