Electrolyte for fluoride ion battery and fluoride ion battery

A fluoride ion battery comprising a cathode active material layer, an anode active material layer, and an electrolyte layer formed between the cathode active material layer and the anode active material layer, wherein

• the cathode active material layer includes a cathode active material comprising at least one kind of metal simple substance, alloy, metal oxide, carbon material, and fluorides thereof, and the cathode active material is an active material that is defluoridated during discharge,
• the anode active material layer includes an anode active material comprising at least one kind of metal simple substance, alloy, metal oxide, and fluorides thereof, and the anode active material is an active material that is fluoridated during discharge,
• the electrolyte layer includes an electrolyte containing a fluoride complex salt as at least one of LiPF6 and LiBF4, and one or more organic solvents, and the electrolyte layer does not contain a fluoride salt having a fluoride ion as an anion component, and
• B/A is 0.125 or more and 1 or less in the case when a total amount of all organic solvents in the electrolyte layer is regarded as A (mol) and a total amount of all the fluoride complex salt in the electrolyte layer is regarded as B (mol).