| abstract |
Provided are a positive electrode active material, a positive electrode and a battery, and a battery pack, an electronic device, an electric vehicle, a power storage device, and an electric power system using the positive electrode active material, the positive electrode, and the battery that can suppress increase in resistance and improve cycle characteristics. The positive electrode includes a positive electrode active material. The positive electrode active material is a layered rock salt type lithium metal oxide containing lithium and at least one metal selected from the group consisting of Ni, Co, Fe, Mn, Cu, Zn, Al, Cr, V, Ti, Mg, and Zr. The site occupancy of metal ions other than lithium at 3a sites obtained by Rietveld analysis of the powder X-ray diffraction pattern of the first positive electrode material for the positive electrode in a discharged state is 5%. The site occupancy of the metal ions other than the metal that occupies a part of the 3b site in the 3b site is 1% or more and is covered with a coating, and the exposure amount from the coating is 0. It is 05% or more and 8% or less. [Selection] Figure 2 |