The present invention relates to a positive electrode active material having improved electrical characteristics by adjusting an aspect ratio gradient of primary particles included in a secondary particle, a positive electrode including the positive electrode active material, and a lithium secondary battery using the positive electrode.

Disclosed is a lithium complex oxide and method of manufacturing the same, more particularly, a lithium complex oxide effective in improving the characteristics of capacity, resistance, and lifetime with reduced residual lithium and with different interplanar distances of crystalline structure between a primary particle locating in an internal part of secondary particle and a primary particle locating on the surface part of the secondary particle, and a method of preparing the same.

A process for making a mixed metal oxide, may involve: (a) providing a hydroxide or oxyhydroxide of TM with an average particle diameter (D50) in the range of from 0.1 μm to 5 mm; (b) subjecting the hydroxide or oxyhydroxide of TM to a stream of gas with a temperature in the range of from 150 to 2000° C., wherein TM contains nickel and at least one further transition metal selected from cobalt and manganese.

The positive electrode active material has high capacity and high output and exhibiting excellent cycle characteristics when being used for a positive electrode of a non-aqueous electrolyte secondary battery. A positive electrode active material for a lithium ion secondary battery contains: a lithium-metal composite oxide containing secondary particles with a plurality of aggregated primary particles; and a compound containing lithium and tungsten present on surfaces of the primary particles. The amount of tungsten contained in the compound containing lithium and tungsten is 0.5 atom % or more and 3.0 atom % or less in terms of a ratio of the number of atoms of W with respect to the total number of atoms of Ni, Co, and an element M, and a conductivity when the positive electrode active material is compressed to 4.0 g/cm.sup.3 as determined by powder resistance measurement is 6×10.sup.−3 S/cm or less.

The present invention relates to a cathode active material, and a lithium secondary battery comprising the same, the present invention provides a cathode active material, represented by the following Chemical Formula 1, wherein I003/I104 ratio is 1.6 or more, and R-factor value represented by the following Formula 1 is 0.40 to 0.44, and c-axis lattice constant (c) and a-axis lattice constant (a) satisfy 3(a)+5.555≤(c)≤3(a)+5.580:
R-factor=(I102+I006)/(I101)  Formula 1 wherein I003, I006, I101, I102, and I104 are the intensity of diffraction peaks on the (003), (006), (101), (102), and (104) planes by X-ray diffraction analysis using CuKα-rays,
Li.sub.α[(Ni.sub.xCo.sub.y).sub.1-βA.sub.β]O.sub.z  Chemical Formula 1 in the Chemical Formula 1, 0.95≤α≤1.1, 0.75≤x≤0.95, 0.03≤y≤0.25, 0<β≤0.2, and 1.9≤z≤2.1, and A is a dopant metal element, and the average oxidation number N of A is 3.05≤N≤3.35.

A positive active material for a rechargeable lithium battery includes a lithium nickel-based composite oxide including a secondary particle in which a plurality of plate-shaped primary particles are agglomerated; and a lithium manganese composite oxide having at least two crystal lattice structures, wherein the secondary particle has a regular array structure in which (003) planes of the primary particles are oriented in a vertical direction with respect to the surface of the secondary particle.

Cathode material from exhausted lithium ion batteries are dissolved in a solution for extracting the useful elements Co (cobalt), Ni (nickel), Al (Aluminum) and Mn (manganese) to produce active cathode materials for new batteries. The solution includes compounds of desirable materials such as cobalt, nickel, aluminum and manganese dissolved as compounds from the exhausted cathode material of spent cells. Depending on a desired proportion, or ratio, of the desired materials, raw materials are added to the solution to achieve the desired ratio of the commingled compounds for the recycled cathode material for new cells. The desired materials precipitate out of solution without extensive heating or separation of the desired materials into individual compounds or elements. The resulting active cathode material has the predetermined ratio for use in new cells, and avoids high heat typically required to separate the useful elements because the desired materials remain commingled in solution.

This positive electrode active material for nonaqueous electrolyte secondary batteries contains a lithium transition metal composite oxide which contains 80% by mole or more of Ni relative to the total number of moles of the metal elements excluding Li, and at least one of Mn and Al, wherein: the total amount of Mn and Al is 5% by mole or more relative to the total number of moles of the metal elements excluding Li; and with respect to a filtrate of a suspension, which has been prepared by adding 250 mg of the positive electrode active material to 10 mL of a 17.5 mass% aqueous solution of hydrochloric acid, dissolving the positive electrode active material therein by 2-hour heating at 90° C., and subsequently diluting the solution to 50 mL, the elution amount of S in the filtrate as determined by inductively coupled plasma mass spectrometry is 0.002 mmol or more.

Provided are a positive electrode active material for a rechargeable lithium battery, a method of preparing the same, and a rechargeable lithium battery including the same, the positive electrode active material for a rechargeable lithium battery including a secondary particle in which a plurality of primary particles including a lithium nickel-based composite oxide are aggregated, wherein at least a portion of the primary particles are arranged radially, a boron coating layer on the surface of the secondary particles and containing lithium borate, and a boron-doped layer inside the primary particle exposed to the surface of the secondary particle.

A process for producing a lithium transition metal oxide is provided. The process comprises pre-calcination of a transition metal precursor in the absence of a lithium source followed by a high-temperature calcination of the pre-calcined intermediate compound in the presence of a lithium source.