The Future ain't what it used to be.
I believe this is the initial press release, from Honda Research Institute, also the University of North Carolina, CalTech, Berkeley, JPL and NASA have been mentioned.
http://hondanews.com/releases/honda...rchers-develop-breakthrough-battery-chemistry
The breakthrough here is a molecule called bis(2,2,2-trifluoroethyl)ether, or BTFE. This solvent is what helps keep the fluoride ion stable so that it can shuttle electrons back and forth in the battery. The key is that it's a liquid at room temperature, earlier flouride batteries are solid state and work only above 160C.
Flouride batteries work in the opposite direction from what you are used to. Instead of shuttling positive cations, they shuttle negative anions. I imagine a big problem these researchers are having is their anodes are dissolving after only a few charges.
Flouride and fluorine are two different things. As long as they can keep the molecules from splitting apart and releasing fluorine on it's own this will be pretty safe. And that will be extremely easy. Flourine was proposed as an element in 1810 and no one was able to isolate it for over 75 years. Once fluorine is combined with another element, especially carbon, it is extremely hard to get it back apart. It should also be relatively safe as far as starting fires. The greatest danger for this battery may be ingestion, and long term bio persistence.
Having said all that... fluorine ions on their own are extremely dangerous, nearly always fatal when breathed in even mild concentrations. Hydroflouric acid too.
No one has ever said "what the world needs now is another fluorocarbon." It's a sad, sad history.