There is a few things we should demand from a decent power supply. Not least, it should not require oven-like temperatures to function. That's just a given.
For decades, fluoride has sat on the sidelines as a potential competitor for lithium-ion batteries. If not more than 150 degrees Celsius (300 degrees Fahrenheit), fluoride could be ahead in the game. Now, it looks like you're shake up in the battery business.
"Caltech researcher Robert Grubbs, famous for winning at the Nobel Prize in Chemistry in 2005," said Caltech researcher Robert Grubbs, famous for winning at the Nobel Prize in Chemistry.
That means potentially plugging into your smartphone once a week, rather than once a day. Or, if spacecraft are more your thing, packing more power into a smaller cell to save vital weight.
The type of electrochemical technology supplying power to your smart devices makes use of positively charged lithium 'Li2 +' cations as a kind of chemical 'piston' to draw an electrical charge through a circuit.
At full charge, a supply of cations occupy the battery's anode. Once the circuit is closed, ions surge into the cathode, producing the all-important work. To reset the cell, all that is required is a voltage to push the lithium piston back again.
Of course, this piston can work in reverse as well. Negative ions such as fluoride (F-) can also create the voltage necessary to draw electrons through a conductor.
In fact, in some ways they can do better job, thanks to the lower number of charges per ion.
"For a battery that lasts longer," says Simon Jones, a researcher at NASA's Jet Propulsion Laboratory.
"Moving multiply-charged metal cations is difficult, but a similar result can be achieved by moving several singly-charged anions, which travel with comparative ease."
Wafer with a tray of drinks. One waiter with a tray of drinks might seem to be more efficient, but a couple of lithe waiters with a drink can be more easily.
As such, technology based on small anions could in theory make a better battery. And fluoride has a low enough atomic mass to have attracted attention since the 1970s.
"But it can be challenging to work with, in particular because it's corrosive and reactive," says Grubbs.
This is not to say nobody has successfully made a functional fluoride ion battery. But they are part of a solid structure. Not at room temperature at least.
Beyond 150 degrees Celsius (300 degrees Fahrenheit) this is less of an issue. Of course, now you need to crank up a muffin.
To get around this, the Caltech researchers took a gamble on an electrolyte solvent called bis (2,2,2-trifluoroethyl) ether. Or BTFE for short.
On the other side of the world, the team will be able to find the right answer.
The end formula is stable, allows for a high degree of efficiency, and can tolerate operation at a variety of voltages.
Copper-lanthanum trifluoride, was found to be an efficient anion-based battery that can be recharged and discharged without the need to crank the heat.
"Says Jones," We are still in the early stages of development, but this is the first rechargeable fluoride battery that works at room temperature.
I know, we might need to wait for more, but this is an exciting step – we can hardly wait for this to become the market.
This research was published in Science.