A battery 2000 of the present disclosure includes a positive electrode 201, a negative electrode 203, and an electrolyte layer 202 provided between the positive electrode 201 and the negative electrode 203. The positive electrode 201 contains a positive electrode active material 111 and a first solid electrolyte 112. The electrolyte layer 202 contains a second solid electrolyte 113. The first solid electrolyte 112 contains lithium and two or more types of anions. The second solid electrolyte 113 contains lithium and two or more types of anions. The molar ratio of Br to the two or more types of anions contained in the first solid electrolyte 112 is smaller than the molar ratio of Br to the two or more types of anions contained in the second solid electrolyte 113.