Are fluoride-ion batteries the future of electrochemical energy storage?

Fluoride-ion batteries (FIBs) have recently emerged as a candidate for the next generation of electrochemical energy storage technologies. On paper, FIBs have the potential to match or even surpass lithium-metal chemistries in terms of energy density, while further eliminating the dependence on strained resources, such as lithium and cobalt.

What is a fluoride-ion battery?

The concept of the fluoride-ion battery was first demonstrated using conversion-type electrodes. 10 In the context of FIBs, the conversion reaction involves the electrochemical transformation between any metal and its corresponding metal fluoride M + xF − ↔ MF x + xe −.

Can fluoride-ion batteries be commercialized?

Among the available candidates, fluoride-ion batteries (FIBs) are a promising technology because of their high theoretical energy density and utilization of abundant and widespread materials. However, FIBs present several new challenges that have prevented them from reaching commercialization.

Which fluorinated compounds are used in batteries?

Among various fluorinated compounds used in batteries, poly (vinylidene fluoride) (PVDF) binders and lithium hexafluorophosphate (LiPF 6) salts have been successfully commercialized as binders for Ni-rich [Ni 1–x–y Co x Mn y]O 2 (NCM) cathodes and electrolytes, respectively .

How does a fluoride-ion battery maintain charge neutrality?

Batteries release energy as electrons move from a material with a high Fermi level (anode) to one with a low Fermi level (cathode). In a fluoride-ion battery, charge neutrality is maintained by the concurrent removal of fluoride ions from the cathode material and insertion of fluoride ions in the anode material (Figure 2).

Can lithium-fluoride batteries be converted?

A research team led by Professor Li Chilin from the Shanghai Institute of Ceramics (SIC) of the Chinese Academy of Sciences has recently made progress in conversion-type lithium-fluoride batteries.