LITHIUM SECONDARY CELL

In a lithium secondary cell, a positive electrode includes a sheet-like positive current collector having conductivity and a positive active material plate that is a plate-like ceramic sintered body containing a lithium composite oxide. The positive active material plate is bonded to the positive current collector via a conductive bonding layer. The positive active material plate is penetrated by the conductive bonding layer through a surface of the positive active material plate facing the positive current collector. A penetration depth of the conductive bonding layer in the positive active material plate with respect to a direction of superposition is 3% or more and 80% or less of a thickness of the positive active material plate.