A secondary battery includes a positive electrode plate and an electrolyte solution. The positive electrode plate includes a positive current collector and a positive electrode film provided on at least one surface of the positive current collector. The positive electrode film includes a positive electrode active material and a lithium supplement. The lithium supplement includes at least one of substances represented by formula (I) below, and the positive electrode film and/or electrolyte solution comprises one or more nitrone derivatives, a molecule of each of which includes a structure represented by formula (II) below: