According to one embodiment, a secondary battery includes a positive electrode, a negative electrode, a nonaqueous electrolyte and a separator. The positive electrode includes a halide including one or more metal elements selected from the group consisting of copper, iron, nickel, cobalt, tin, and zinc. The negative electrode includes one or more selected from the group consisting of lithium metal, a lithium alloy, and a compound capable of having Li inserted and extracted. The nonaqueous electrolyte contains aluminum ions. The separator has lithium ion conductivity and is interposed between the positive electrode and the negative electrode.