COATED ACTIVE MATERIAL, POSITIVE ELECTRODE MATERIAL, POSITIVE ELECTRODE, AND BATTERY

A coated active material includes a positive electrode active material and a coating layer including a first solid electrolyte and coating at least a portion of a surface of the positive electrode active material. The first solid electrolyte contains Li, Ti, M, and X, the M is at least one selected from the group consisting of metalloid elements and metal elements other than Li and Ti, and the X is at least one selected from the group consisting of F, Cl, Br, and I. A quotient obtained by the following mathematical expression (A), is 1.9 or more and 6.9 or less.