There is provided a method for collecting and reusing an active material from positive electrode scrap. The positive electrode active material reuse method of the present disclosure includes (a) thermally treating positive electrode scrap comprising a lithium composite transition metal oxide positive electrode active material layer on a current collector in air at 300 to 650° C. for 1 hour or less for thermal decomposition of a binder and a conductive material in the active material layer, to separate the current collector from the active material layer, and collecting an active material in the active material layer, and (b) annealing the collected active material with an addition of a lithium precursor to obtain a reusable active material.

A composite electrode active material is described herein, which comprises two or more electrode active materials blended or structurally-integrated together, in one of the materials is a lithiated spinel selected from the group consisting of (a) a lithiated spinel of formula LiMn.sub.xNi.sub.yM.sub.zO.sub.2; wherein M comprises at least one metal cation other than manganese and nickel cations; x+y+z=1; 0<x<1.0; 0<y<1.0; 0≤z≤0.5; and the ratio of x:y is in the range of about 1:2 to about 2:1; and (b) a lithiated spinel of formula LiM.sup.1O.sub.2, wherein M.sup.1 comprises a combination of Mn and Ni transition metal ions in a ratio of Mn to Ni ions of about 2:1 to about 1:1.

A lithium transition metal oxide capable of minimizing a side reaction with an electrolyte, thereby suppressing the generation of gas during charging and discharging of a lithium secondary battery is provided. A lithium transition metal oxide is represented by Chemical Formula 1, wherein a lattice parameter of a unit lattice satisfies Equations 1 and 2. A positive electrode additive for a lithium secondary battery, and a lithium secondary battery are also provided.

A composite positive active material for a lithium secondary battery including a lithium cobalt-based oxide; a method of preparing the same; and a lithium secondary battery including a positive electrode for a lithium secondary battery including the composite positive active material are provided. The composite positive active material for a lithium secondary battery includes the lithium cobalt-based oxide, a particle coating part in a form of islands on one surface of the lithium cobalt-based oxide, the particle coating part including a first coating layer containing lithium titanium-based oxide, and a surface coating part in an internal region of another surface of the lithium cobalt-based oxide.

Provided is a method for producing a lithium transition metal oxide, comprising, A) mixing a lithium salt and a precursor, adding the mixture into a reactor for precalcination; the lithium salt has a particle size D50 of 10-20 μm and the precursor has a particle size D50 of 1-20 μm, and the precursor is one or more selected from transition metal oxyhydroxide, transition metal hydroxide and transition metal carbonate; and B) adding the product obtained from the precalcination into a fluidized bed reactor, subjecting to a first calcination and a second calcination to obtain the lithium transition metal oxide. Raw materials for the lithium transition metal oxide further includes a main-group metal compound containing oxygen, which is added in the precalcination, the first calcination or the second calcination; and the main-group metal compound containing oxygen has an average particle size of 10-100 nm. A fluidized bed reactor is also provided.

A positive electrode active material for a non-aqueous electrolyte secondary battery includes LiX, where X represents a halogen atom.

A lithium secondary cell having an operating voltage ≥4.35V, comprising a cathode comprising a doped LiCoO.sub.2 active material, an anode comprising graphite, and an electrolyte comprising a carbonate-based solvent, a lithium salt and both a succinonitrile (SN) and a lithium bis(oxalato)borate (LiBOB) additive wherein during the discharge at 45° C. from a state of charge (SOC) of 100% at 4.5V to a SOC of 0 at 3V at a C/10 rate the difference of the SOC at 4.42V and 4.35V is at least 7% but less than 14%, and wherein the active material is doped by at least 0.5 mole % of either one or more of Mn, Mg and Ti.

The present invention belongs to the field of materials, and relates to an environment-friendly precursor, a cathode material for a lithium-ion battery, and preparation methods thereof. The method for preparing an environment-friendly precursor provided in the present invention includes: subjecting a metal and/or a metal oxide, an oxidant, water, and a complexing agent to a chemical corrosion crystallization reaction at an electrical conductivity equal to or greater than 200 uS/cm, a redox potential ORP value equal to or less than 100 my, and a complexing agent concentration of 3-50 g/L. The precursor prepared by using the method provided in the present invention has advantages that no waste water is produced during dissolution and crystallization, and that water is constantly consumed, so that the purpose of environmental friendliness can be achieved. Moreover, the first charge and discharge efficiency of a lithium-ion battery can be effectively improved by means of the precursor.

A lithium-cobalt-based composite oxide used for a positive electrode active material of an electrochemical device, wherein the lithium-cobalt-based composite oxide has elutable fluoride ions, the elutable fluoride ions being eluted to an eluate when the lithium-cobalt-based composite oxide is dispersed to ultrapure water, in a mass ratio of 500 ppm or more and 15000 ppm or less in comparison with the lithium-cobalt-based composite oxide, and the lithium-cobalt-based composite oxide has a composition shown by the following general formula (1): Li.sub.1-xCo.sub.1-zM.sub.zO.sub.2-aF.sub.a (−0.1≦x<1, 0≦z<1, 0≦a<2) . . . (1) (wherein, M represents one or more kinds of metal element selected from the group of Mn, Ni, Fe, V, Cr, Al, Nb, Ti, Cu, and Zn).

The present invention provides, as a lithium-containing transition metal oxide, a substance which is given by the chemical compositional formula Li.sub.4M.sub.5O.sub.12 (M=Cr, Co, or Zr) and has a spinel-type crystal structure. Provided is a lithium ion secondary cell having a positive electrode configured from a lithium-containing transition metal oxide which has a spinel-type crystal structure and has the chemical compositional formula Li.sub.4M.sub.5O.sub.12 (M=Cr or Co). The present invention further provides a lithium ion secondary cell having a negative electrode configured from a lithium-containing transition metal oxide which has a spinel-type crystal structure and has the chemical compositional formula Li.sub.4M.sub.5O.sub.12 (M=Zr).