Processes are provided in which successive steps of hydrometallurgical value extraction may be carried out using the products of carbon capture and an electrolytic reagent-generating process. The electrolytic process provides an acid leachant and an alkali hydroxide, with the alkali hydroxide then available for use either directly as a precipitant in the hydrometallurgical steps, or available for conversion by carbon capture to an alkali metal carbonate that can in turn be used as the precipitant in the selective hydrometallurgical steps.

Processes are provided in which successive steps of hydrometallurgical value extraction may be carried out using the products of carbon capture and an electrolytic reagent-generating process. The electrolytic process provides an acid leachant and an alkali hydroxide, with the alkali hydroxide then available for use either directly as a precipitant in the hydrometallurgical steps, or available for conversion by carbon capture to an alkali metal carbonate that can in turn be used as the precipitant in the selective hydrometallurgical steps.

The present exemplary embodiments relate to a positive electrode active material for a lithium secondary battery, and a lithium secondary battery including the same. The positive electrode active material for a lithium secondary battery according to an exemplary embodiment includes: a metal oxide in the form of a single particle; and a coating layer positioned on the surface of the metal oxide, wherein a concentration of lithium in a to thickness area based on the total thickness of the coating layer has a lower value than a concentration of lithium in the metal oxide.

The present exemplary embodiments relate to a positive electrode active material for a lithium secondary battery, and a lithium secondary battery including the same. The positive electrode active material for a lithium secondary battery according to an exemplary embodiment includes: a metal oxide in the form of a single particle; and a coating layer positioned on the surface of the metal oxide, wherein a concentration of lithium in a to thickness area based on the total thickness of the coating layer has a lower value than a concentration of lithium in the metal oxide.

A metal composite compound is provided with which a lithium secondary battery having high initial charge and discharge efficiency can be produced. A metal composite compound containing at least Ni, in which in the metal composite compound, when in a differential pore volume distribution determined by a Barrett-Joyner-Halenda method from a nitrogen gas adsorption isotherm, an integrated area of a region where a pore diameter is 1 nm or more and 50 nm or less is A, and an integrated area of a region where the pore diameter is more than 50 nm and 200 nm or less is B, A/B is 0.05 or more and less than 1.5.

The present exemplary embodiments relate to a positive electrode active material for a lithium secondary battery, and a lithium secondary battery including the same. The positive electrode active material for a lithium secondary battery according to an exemplary embodiment includes: a metal oxide which is in the form of a single particle and includes a layered structure; and a coating layer which is positioned on the surface of the metal oxide and includes a layered structure, wherein an average interplanar distance value of the layered structure included in the coating layer is smaller than an average interplanar distance value of the layered structure included in the metal oxide.

The present exemplary embodiments relate to a positive electrode active material for a lithium secondary battery, and a lithium secondary battery including the same. The positive electrode active material for a lithium secondary battery according to an exemplary embodiment includes: a metal oxide which is in the form of a single particle and includes a layered structure; and a coating layer which is positioned on the surface of the metal oxide and includes a layered structure, wherein an average interplanar distance value of the layered structure included in the coating layer is smaller than an average interplanar distance value of the layered structure included in the metal oxide.

A positive electrode active material, a method of preparing the same, a positive electrode including the same, and a rechargeable lithium battery including the positive electrode are provided. The positive electrode active material includes a lithium composite oxide, and a coating layer on a surface of the lithium composite oxide. The positive electrode active material further includes sodium (Na) and sulfur (S), wherein a mass fraction (S/Na) of the S to the Na is in a range of about 1 to about 3.

A method of preparing a positive electrode active material is disclosed. The method may include performing a co-precipitation reaction including a first step of reacting at a pH range of about pH 11 to about pH 12 and a second step of reacting at a pH lower than the first step for a mixture of a nickel precursor and a metal precursor to obtain a nickel-based composite hydroxide, mixing the nickel-based composite hydroxide, an anhydrous lithium hydroxide, an aluminum raw material, and a zirconium raw material and subjecting to a first heat treatment to produce hollow secondary particles, pulverizing the secondary particles, and adding and mixing the pulverized resultant, a cobalt coating raw material, and a zirconium coating raw material into an aqueous (e.g., water-soluble) solvent, and then performing a second heat treatment to obtain a positive electrode active material.

A precursor for sodium-ion battery positive electrode material and a preparation method therefor, a sodium-ion battery positive electrode material, a sodium-ion battery, and an electrical device are provided. The precursor for sodium-ion battery positive electrode material has a chemical general formula of Ni.sub.xMn.sub.yFe.sub.1-x-y(OH).sub.2, wherein 0.15x0.35, and 0.2y0.5. The precursor for sodium-ion battery positive electrode material contains a S element with a content of 4000 ppm, and has a Na/S mass ratio of 1.5.