Positive electrode and nonaqueous electrolyte secondary battery including the same

A positive electrode comprising:

• a positive electrode current collector;
• and
• a positive electrode active material layer placed on the positive electrode current collector (52), wherein
• the positive electrode active material layer contains:
• a first lithium-transition metal composite oxide in a form of secondary particles which are aggregates of 30 or more primary particles,
• a second lithium-transition metal composite oxide in a form of single particles which are primary particles or aggregates of two to ten primary particles,
• in the first lithium-transition metal composite oxide,
• a boron compound is placed on surfaces of the secondary particles, and
• an average porosity of the secondary particles observed in their cross sections of the secondary particles by a scanning electron microscope is 2% to 8%,
• in the second lithium-transition metal composite oxide,
• an aluminum compound is placed on surfaces of the single particles,
• the first and second lithium-transition metal composite oxides each contain nickel (Ni) at 70 mol % or more relative to a total amount of transition metal elements, and
• a mass ratio of the first lithium-transition metal composite oxide:the second lithium-transition metal composite oxide is 80:20 to 50:50.