Abstract: Positive electrode active materials are provided. The positive electrode active materials include a primary particle formed of a plurality of metals including a first metal and a secondary particle formed of at least one of the primary particle. The secondary particle includes a center part, a surface part, a seed region where the primary particle having concentration gradient of the first metal is disposed, and a maintain region where the primary particle having constant concentration of the first metal is disposed, the seed region adjacent to the core part and a maintain region adjacent to the surface part, the length of the seed region in a direction from the center part to the surface part is 1 ?m.

Abstract: A positive active material is provided. The positive active material may include lithium, an additive metal, and at least one of nickel, cobalt, manganese, or aluminum. The additive metal may include an element different from nickel, cobalt, manganese, and aluminum, and an average content of the additive metal may be less than 2 mol %.

Abstract: Positive electrode active materials are provided. The positive electrode active materials includes a primary particle formed of a plurality of metals including a first metal and a secondary particle formed of at least one of the primary particle. The secondary particle includes a core part, a shell part, a seed region where the primary particle having concentration gradient of the first metal is disposed and a maintain region where the primary particle having constant concentration of the first metal is disposed, the seed region adjacent to the core part and a maintain region adjacent to the sell part, and length of the seed region in a direction from the core part to the shell part is 1 ?m.

Abstract: Positive electrode active materials are provided. The positive electrode active materials includes a primary particle formed of a plurality of metals including a first metal and a secondary particle formed of at least one of the primary particle. The secondary particle includes a core part, a shell part, a seed region where the primary particle having concentration gradient of the first metal is disposed and a maintain region where the primary particle having constant concentration of the first metal is disposed, the seed region adjacent to the core part and a maintain region adjacent to the sell part, and length of the seed region in a direction from the core part to the shell part is 1 ?m.

Abstract: A positive active material is provided. The positive active material may include lithium, an additive metal, and at least one of nickel, cobalt, manganese, or aluminum. The additive metal may include an element different from nickel, cobalt, manganese, and aluminum, and an average content of the additive metal may be less than 2 mol %.

Abstract: Positive electrode active materials are provided. The positive electrode active materials includes a primary particle formed of a plurality of metals including a first metal and a secondary particle formed of at least one of the primary particle. The secondary particle includes a core part, a shell part, a seed region where the primary particle having concentration gradient of the first metal is disposed and a maintain region where the primary particle having constant concentration of the first metal is disposed, the seed region adjacent to the core part and a maintain region adjacent to the sell part, and length of the seed region in a direction from the core part to the shell part is 1 ?m.