Lithium secondary battery

A lithium secondary battery comprising:

• a positive electrode plate that is a lithium complex oxide sintered plate with a thickness of 50 μm or more;
• a negative electrode plate;
• a separator interposed between the positive electrode plate and the negative electrode plate;
• and an electrolytic solution,
• wherein the lithium complex oxide sintered plate has a structure in which a plurality of primary grains having a layered rock-salt structure are bonded,
• wherein the lithium complex oxide has a composition represented by Lix(Co1-yMy)O2±δ, wherein 1.0≤x≤1.1, 0<y≤0.8, and 0≤δ<1 are satisfied, and M is at least one selected from the group consisting of Mg, Ni, Al, Ti, and Mn, and
• wherein the plurality of primary grains have a mean tilt angle of over 0° and 30° or less, the mean tilt angle being a mean value of angles defined by (003) planes of the plurality of primary grains and a plate face of the lithium complex oxide sintered plate.