A cathode active material precursor for a lithium metal oxide is provided. The cathode active material precursor comprises a metal-containing oxyhydroxide. The metal-containing oxyhydroxide comprises nickel and an additional metal. At least 50 mol. % of the nickel of the metal-containing oxyhydroxide has an oxidation state of +3. A method of forming a cathode active material precursor is also provided. The method comprises combining a nickel-containing compound, an additional metal-containing compound, an oxidizing agent, and a solvent to form a solution. The method further comprises exposing the solution to heat at a temperature of from about 30° C. to about 90° C. to form a precipitate comprising the metal-containing oxyhydroxide.

A cathode active material precursor for a lithium metal oxide is provided. The cathode active material precursor comprises a metal-containing oxyhydroxide. The metal-containing oxyhydroxide comprises nickel and an additional metal. At least 50 mol. % of the nickel of the metal-containing oxyhydroxide has an oxidation state of +3. A method of forming a cathode active material precursor is also provided. The method comprises combining a nickel-containing compound, an additional metal-containing compound, an oxidizing agent, and a solvent to form a solution. The method further comprises exposing the solution to heat at a temperature of from about 30° C. to about 90° C. to form a precipitate comprising the metal-containing oxyhydroxide.

Cathode active material in particulate form with a mean particle diameter in the range from 2 to 16 .Math.m (D50), wherein the cathode active material has the composition Li.sub.1+xTM.sub.1-xO.sub.2 wherein x is in the range of from 0.1 to 0.2 and TM is a combination of elements according to general formula (I), (Ni.sub.aCo.sub.bMn.sub.c).sub.1-d-eM.sup.1.sub.dM.sup.2.sub.e where the variables are each defined as follows: a is in the range from 0.20 to 0.40, b is in the range of from zero to 0.15, c is in the range of from 0.50 to 0.75, d is in the range of from zero to 0.015, and e is in the range of from zero to 0.02, M.sup.1 is selected from Al, Ti, Zr, Mo, W, Fe, Nb, and Mg, M.sup.2 is selected from B and K, with a + b + c = 1.0 wherein said composite oxide has a specific surface (BET) in the range from 0.5 m.sup.2/gto 10 m.sup.2/gand a pressed density of at least 2.9 g/cm.sup.3, and wherein said cathode active material has an average primary particle diameter in the range of from 200 to 3,000 nm.

Process for making a partially coated electrode active material wherein said process comprises the following steps: (a) Providing an electrode active material according to general formula Li.sub.1+xTM.sub.1-xO.sub.2, wherein TM is Ni and, optionally, at least one of Co and Mn, and, optionally, at least one element selected from Al, Mg, and Ba, transition metals other than Ni, Co, and Mn, and x is in the range of from zero to 0.2, wherein at least 50 mole-% of the transition metal of TM is Ni, (b) treating said electrode active material with an aqueous medium, (c) partially removing water by solid-liquid separation method, (d) treating the solid residue with an aqueous formulation of at least one heteropolyacid or its respective ammonium or lithium salt, (e) treating the residue thermally.

The present disclosure relates to a positive active material including a lithium transition metal oxide substituted with Na, W, Mg, Ti, and S, a method of preparing the same, and a lithium secondary battery having a positive electrode including the positive active material.

The invention relates to a method for preparing materials with composition gradient characteristics. After mixing a lithium source with the prepared precursor, raise the temperature from room temperature to 300° C.˜600° C. at 2° C./min˜10° C./min and maintain it, and then sinter for 5 hours˜18 hours, cool with the furnace, then raise the temperature from room temperature to 600° C.˜1200° C. at 2° C./min˜10° C./min and maintain it, and sinter for 5 hours˜18 hours, and the material is thus obtained. The material prepared with the method provided by the invention has composition gradient characteristic, and its application to the positive electrode of battery enables the battery to have higher energy density and better thermal stability, and prolonged service life.

Embodiments related to cation-disordered lithium metal oxide compounds, their methods of manufacture, and use are described. In one embodiment, a cation-disordered lithium metal oxide includes Li.sub.aM.sub.bM′.sub.cO.sub.2 with a greater than 1. M includes at least one redox-active species with a first oxidation state n and an oxidation state n′ greater than n, and M is chosen such that a lithium-M oxide having a formula LiMO.sub.2 forms a cation-disordered rocksalt structure. M′ includes at least one charge-compensating species that has an oxidation state y that is greater than n.

A method for producing a lithium-transition metal composite oxide, including steps of: preparing a mixture including a lithium-containing compound and a transition metal compound; obtaining a molded body of the mixture; and sintering the molded bodies in a container having at least one vent hole, to obtain sintered bodies.

A method for producing a lithium-transition metal composite oxide, including steps of: preparing a mixture including a lithium-containing compound and a transition metal compound; obtaining a molded body of the mixture; and sintering the molded bodies in a container having at least one vent hole, to obtain sintered bodies.

A positive electrode active material with little deterioration is provided. Positive electrode active material particles with little deterioration are provided. A power storage device with little deterioration is provided. A highly safe power storage device is provided. A novel power storage device is provided. A secondary battery includes a positive electrode and a negative electrode. In the secondary battery, the positive electrode includes a positive electrode active material; the positive electrode active material includes a crystal exhibiting a layered rock-salt crystal structure; the crystal is represented by the space group R-3m; the positive electrode active material is a particle containing lithium, cobalt, titanium, magnesium, and oxygen; the concentration of the magnesium in a surface portion of the particle is higher than the concentration of the magnesium in an inner portion of the particle; and in the positive electrode active material, the concentration of the titanium in the surface portion of the particle is higher than the concentration of the titanium in the inner portion of the particle.