Abstract: The application relates to a positive active material precursor including a transition metal composite oxide precursor. The transition metal composite oxide precursor exhibits a peak full width at half maximum of a (200) plane (2?=about 42° to about 44°) in X-ray diffraction analysis in a range of about 0.3° to about 0.5°. The application also relates to a positive active material using the precursor, a method of preparing the same, and a positive electrode and a rechargeable lithium battery including the same.

Abstract: A method of preparing a positive active material involves mixing a nickel compound, a cobalt compound, and optionally a metal compound to obtain a first mixture, subjecting the first mixture to a co-precipitation reaction to obtain a first resulting product, washing with water, filtering and drying the first resulting product to prepare a transition metal hydroxide precursor, subjecting the transition metal hydroxide precursor to a primary heat treatment to prepare a transition metal composite oxide precursor, mixing the transition metal composite oxide precursor and a dehydrated lithium salt to obtain a second mixture, and performing a secondary heat treatment on the second mixture to prepare a nickel-based lithium transition metal oxide. The dehydrated lithium salt is prepared by drying a hydrated lithium salt having an average particle diameter (D50) of about 400-600 ?m and then pulverizing the resultant to have a D50 of about 3-30 ?m.

Abstract: Disclosed are a positive active material for a rechargeable lithium battery, a method of preparing the same, and a rechargeable lithium battery including the same. The positive active material includes a first positive active material in a form of secondary particles including a plurality of primary particles that are aggregated together, and a second positive active material having a single crystal form, wherein both of the first positive active material and the second positive active material are nickel-based positive active materials, each of the first positive active material and the second positive active material is coated with cobalt, and a maximum roughness of a surface of the second positive active material is greater than or equal to about 15 nm.

Abstract: The application relates to a positive active material precursor including a transition metal composite oxide precursor. The transition metal composite oxide precursor exhibits a peak full width at half maximum of a (200) plane (2?=about 42° to about 44°) in X-ray diffraction analysis in a range of about 0.3° to about 0.5°. The application also relates to a positive active material using the precursor, a method of preparing the same, and a positive electrode and a rechargeable lithium battery including the same.