| abstract |
(57) [Problem] Even when lithium manganate (LiMn 2 O 4 ) is used as a main positive electrode active material, self-discharge is suppressed and excellent in discharge storage characteristics and high-temperature storage characteristics, and a high discharge operating voltage. In addition, a positive electrode having a high energy density can be obtained. SOLUTION: The positive electrode of the present invention has a general formula Li 1 + X Mn 2-Y O 4 (provided that the atomic ratio between lithium and manganese is 0.56 ≦ Li / Mn = (1 + X) / (2-Y) ≦ 0.62, -0.2 ≦ X ≦ 0.2 and Y ≦ 1.0), and a general formula Li 1 + Z C oO 2 (provided that −0.5 ≦ Z ≦ 0.5) or a general formula Li 1 + Z NiO 2 (provided that: −0.5 ≦ Z ≦ 0.5) and at least one selected from lithium nickelates represented by the formula: |