Conventional batteries release ions from one electrode to the other allowing electric current to flow between their terminals. Lithium is a popular electro-positive mineral, because it is the most positive on the periodic table. Scientists have challenged the assumption that active electrodes should always be positive. Why not use the most extremely negative mineral to attract ions instead, they ask. This is the principle behind the fluoride-ion battery.
The Potential and the Problems of the Fluoride-Ion Battery
Fluoride is the most electrically-negative element on the periodic table. This thus makes it an obvious candidate for a ‘reverse process’ battery. According to Clean Technica, a fluoride-ion battery is capable of holding ten times more energy than a lithium-ion version.
However, until now the fluoride-ion battery must be heated to 150° C / 300° F to work. Not a good idea at all for a smartphone pressed to your ear, or an electric car. Now Engaget has revealed Honda, NASA, and California Institute of Technology (Caltech) have made a combined breakthrough. Their solution is a liquid electrolyte that dissolves fluoride at room temperature.
Glimpsing Into the Future of Fluoride-Ion Batteries
“Recharging a battery is like pushing a ball up a hill and then letting it roll back again, over and over,” a co-researcher explains. “You go back and forth between storing the energy and using it. For a battery that lasts longer, you need to move a greater number of charges.
“Moving multiply-charged positive metal cations is difficult. However a similar result can be achieved by moving several singly negative charged anions, which travel with comparative ease. The challenges are making the system work at usable voltages. Our fluoride-ion battery study demonstrates that negative anions are indeed worthy of attention in battery science.”
However there’s a big difference between hushed voices in a laboratory, and an electric supercar with ten times more power. This study shows us how turning the battery process upside down could be one way to achieve this ‘little miracle’.
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Preview Image: Schlinger Laboratory for Chemistry and Chemical Engineering
