Manufacturers add sodium-fluoride to toothpaste to help protect against tooth decay. I know that already, you may say, but what has this to do with the world of batteries? If you are curious, then you may like to know that Argonne scientists invented a sodium-fluoride battery electrolyte, that could keep solid batteries lasting longer in future.
Sodium-Fluoride Electrolyte for Batteries Beyond Lithium-Ion
The Argonne website describes the discovery as “an exciting new generation of battery types for electric vehicles beyond lithium ion”. And it goes on to explain how, “non-lithium-ion batteries offer twice or more energy in a given volume or weight”.
Lithium-metal batteries use lithium metal as their anode instead of graphite. The original versions were single-use cells, although research into rechargeable alternatives has been ongoing for a while. The latter are proving to have a high charge density, although this declines rapidly with repeated charges and discharges.
The Argonne team claims to have resolved this disadvantage by introducing a sodium-fluoride battery electrolyte. This is the medium through which ions shuttle between cathode and anode during charging and recharging. Their new electrolyte therefore replaces the traditional lithium salt dissolved in a solvent.
New Sodium Electrolyte Remains Robust Longer
Current-generation lithium-metal batteries fail when a dendrites growth penetrates through a separator, causing a short circuit between the electrodes. However, the next-gen Argonne version resolves this problem with its sodium-fluoride battery electrolyte.
The traditional electrolyte had previously failed to form an adequate protective layer on the anode surface, during the first few charging cycles. But the new electrolyte keeps this electrolyte-interphase intact longer, so the battery in turn can survive for hundreds of cycles.
More Information
Sodium Technology Steals a March on Li-Ion
3-D Exposes Dendrites Forming in Batteries
