Secondary battery

A secondary battery, comprising:

• a positive electrode including a positive electrode active material capable of electrochemically absorbing and releasing lithium ions;
• a negative electrode including a negative electrode active material capable of electrochemically absorbing and releasing lithium ions;
• a separator interposed between the positive electrode and the negative electrode;
• and
• a non-aqueous electrolyte, wherein
• the positive electrode includes a positive electrode material mixture containing the positive electrode active material and a positive electrode additive,
• the positive electrode additive includes a compound represented by a general formula:
• LiaFexMyOz, where 0≤a≤5, 0≤x≤5, 0≤y≤1, and 0≤z≤4, with at least two of a, x, y and z being more than 0, and M includes at least one kind selected from the group consisting of Mn, Zn, Al, Ga, Ge, Ti, Si, Sn, Ce, Y, Zr, S, and Na,
• the positive electrode and the negative electrode are spirally wound with the separator interposed between the positive electrode and the negative electrode, into an electrode group,
• a deoxidizing sheet formed by processing a deoxidizing resin into a sheet is placed in a wound state within a space formed at a center of the electrode group, and
• the deoxidizing resin contains a resin that allows oxygen to pass through and a deoxidizing agent dispersed in the resin.