Electrode active material, all solid fluoride ion battery, and method for producing electrode active material

An all solid fluoride ion battery comprising:

• a cathode active material layer containing a cathode active material, an anode active material layer containing an anode active material, and a solid electrolyte layer formed between the cathode active material layer and the anode active material layer;
• wherein
• the cathode active material or the anode active material is an electrode active material comprising:
• an active material region that contains an active material component including a layered structure;
• and
• a coating region positioned in a surface side of the active material region;
• the electrode active material functions as an active material by intercalation and desorption of fluoride ions;
• the active material component includes a layered Perovskite structure and a crystal phase represented by An+1BnO3n+1−αFx, in which A includes at least one selected from the group consisting of an alkali earth metal element and a rare earth element, B includes at least one selected from the group consisting of Mn, Co, Ti, Cr, Fe, Cu, Zn, V, Ni, Zr, Nb, Mo, Ru, Pd, W, Re, Bi, and Sb, n is 1 or 2, α satisfies 0≤α≤2, and x satisfies 0≤x≤2.2, and
• wherein a fluorine concentration (atomic %) in the active material region is regarded as F1, and wherein a fluorine concentration (atomic %) in the coating region is regarded as F2, such that a fluorinating ratio F2/F1 is 1.5 or higher.