Fluoride ion battery electrolyte compositions

A fluoride ion battery comprising:

• lithium-free electrodes, the electrodes including an anode and cathode, at least one of the electrodes containing fluorine, wherein said anode comprises a material selected from the group consisting of a metal, a metal alloy, a metal oxide, a metal fluoride, an alloy metal fluoride, a metal oxide fluoride, a polyaniline, and a polypyrrole, and wherein said cathode comprises a material selected from the group consisting of a metal, a metal alloy, a metal oxide, a metal fluoride, an alloy metal fluoride, a metal oxide fluoride, a polyaniline, and a polypyrrole;
• wherein said cathode and said anode comprise different materials;
• and
• a lithium-free electrolyte comprising an organic-soluble fluoride salt dissolved in a solvent, wherein the electrolyte is a liquid;
• wherein said organic-soluble fluoride salt comprises a fluorine-substituted or unsubstituted alkylammonium cation having the formula:
• R1R2R3R4N+ or a fluorine-substituted or unsubstituted alkylphosphonium cation having the formula:
• R1R2R3R4P+;
• wherein each of R1, R2, R3 and R4 is independently a fluorine-substituted or unsubstituted C1 to C50 aliphatic group, a C1 to C50 cyclic aliphatic group, a C1 to C50 fluoroalkyl group, a C1 to C50 oligo(ethyleneglycol) group, a C1 to C50 alkyl group, or a C4 to C50 aryl group;
• and wherein at least one of R1, R2, R3 and R4 is said C1 to C50 alkyl group.