The present disclosure provides a cathode material and a method for preparing the cathode material, a cathode, a lithium ion battery and a vehicle. The cathode material comprises a matrix particle, wherein the matrix particle is a monocrystal particle comprising nickel lithium manganate and nickel cobalt lithium manganate. A position in the matrix particle close to a surface layer is provided with a buffer layer. A content of at least one of elements Ni, Co and Mn in the buffer layer is lower than contents thereof in other positions of the matrix particle. The cathode material has at least one of advantages of relatively high specific capacity, cycling stability, better safety performance and the like, and the buffer layer can alleviate erosion by an electrolyte and inhibit separation of active oxygen.

A cathode active material for a lithium secondary battery includes lithium transition metal oxide particles, wherein the lithium transition metal oxide particles may include first lithium transition metal oxide particles (first particles) including an interparticular pore and second lithium transition metal oxide particles (second particles) having an average particle diameter within a range of a diameter of the interparticular pore, measured by mercury intrusion porosimetry. By including first particles including an interparticular pore and second particles having an average particle diameter within a range of a diameter of the interparticular pore measured by mercury intrusion porosimetry, the cathode active material may have a reduced interparticular pore present therein. Accordingly, the cathode active material may have an improved pellet density. Consequently, when a lithium secondary battery is manufactured using the cathode active material, the energy density thereof may improve.

An iron-based oxide magnetic particle powder has a narrow particle size distribution a small content of fine particles that do not contribute to magnetic recording characteristics, and a narrow coercive force distribution, to enhance magnetic recording medium density. Neutralizing an aqueous solution containing a trivalent iron ion and an ion of the metal substituting a part of the Fe sites by adding an alkali to make pH of 1.5 or more and 2.5 or less, adding a hydroxycarboxylic acid, and further neutralizing by adding an alkali to make pH of 8.0 or more and 9.0 or less are performed at 5° C. or more and 25° C. or less. A formed iron oxyhydroxide precipitate containing the substituting metal element is rinsed with water, then coated with silicon oxide, and then heated thereby providing e-type iron-based oxide magnetic particle powder. The rinsed precipitate may be subjected to a hydrothermal treatment.

The present invention provides a positive electrode active material for a secondary battery, which includes a core, a shell disposed to surround the core, and a buffer layer which is disposed between the core and the shell and includes pores and a three-dimensional network structure connecting the core and the shell, wherein, the core, the shell, and the three-dimensional network structure of the buffer layer each independently include a lithium nickel manganese cobalt-based composite metal oxide and at least one metallic element of the nickel, the manganese, and the cobalt has a concentration gradient that gradually changes in any one region of the core, the shell, and the entire positive electrode active material.

A process for recovering a nickel cobalt manganese hydroxide from recycled lithium-ion battery (LIB) material such as black mass, black powder, filter cake, or the like. The recycled LIB material is mixed with water and either sulfuric acid or hydrochloric acid at a pH less than 2. Cobalt, nickel, and manganese oxides from the recycled lithium-ion battery material dissolve into the acidic water with the reductive assistance of gaseous sulfur dioxide. Anode carbon is filtered from the acidic water, leaving the dissolved cobalt, nickel, and manganese oxides in a filtrate. The filtrate is mixed with aqueous sodium hydroxide at a pH greater than 8. Nickel cobalt manganese hydroxide precipitates from the filtrate. The nickel cobalt manganese hydroxide is filtered from the filtrate and dried. The filtrate may be treated ammonium fluoride or ammonium bifluoride to precipitate lithium fluoride from the filtrate. The composition ratio of nickel to cobalt to manganese in the acid filtrate may be adjusted to a desired ratio. The anode carbon is recovered and purified for reuse.

Process for making an electrode active material wherein said process comprises the following steps: (a) Providing a hydroxide TM(OH).sub.2 or at least one oxide TMO or oxyhydroxide of TM or combination of at least two of the foregoing wherein TM contains at least 99 mol-% Ni and, optionally, in total up to 1 mol-% of at least one metal selected from Ti, Zr, V, Co, Zn, Ba, or Mg, (b) mixing said hydroxide TM(OH).sub.2 or oxide TMO or oxyhydroxide of TM or combination with a source of lithium and an aqueous solution of a compound of Me wherein Me is selected from Al or Ga or a combination of the foregoing and wherein the molar amount of TM corresponds to the sum of Li and Me, (c) removing the water by evaporation, (d) treating the solid residue obtained from step (c) thermally at a temperature in the range of from 500 to 800° C. in the presence of oxygen.

Provided by the present disclosure are a carbonate precursor that has a high-nickel and low-cobalt sandwich structure, a preparation method therefor and an application thereof. The precursor comprises an inner core and an outer shell layer, wherein the outer shell layer covers at least a part of the outer surface of the inner core. The carbonate precursor having the sandwich structure has the advantages of narrow particle size distribution, good fluidity, and an excellent electrochemical performance, and may be stably produced in both an ammonia-free system and an ammonia-containing system.

The present disclosure provides a lithium-rich carbonate precursor, a preparation method therefor, and an application thereof. The lithium-rich carbonate precursor has a solid spherical structure, and the chemical formula of the lithium-rich carbonate precursor is Ni.sub.xCo.sub.yMn.sub.(1−x−y)CO.sub.3. The precursor has the advantages of having controllable particle size, uniform particle size distribution, high sphericity, high tap density, good fluidity, and excellent electrochemical performance and energy density.

A cathode active material for a lithium secondary battery according to an embodiment of the present invention includes a lithium metal oxide particle that contains tungsten and has a secondary shape in which a plurality of primary particles are aggregated. The lithium metal oxide particle includes a sulfur-containing portion formed between the primary particles in an inner region of the lithium metal oxide particle.

A positive-electrode active material contains a compound that has a crystal structure belonging to a space group FM3-M and contains is represented by the composition formula (1) and an insulating compound,
Li.sub.xMe.sub.yO.sub.αF.sub.β  (1)
wherein Me denotes one or two or more elements selected from the group consisting of Mn, Co, Ni, Fe, Al, B, Ce, Si, Zr, Nb, Pr, Ti, W, Ge, Mo, Sn, Bi, Cu, Mg, Ca, Ba, Sr, Y, Zn, Ga, Er, La, Sm, Yb, V, and Cr, and the following conditions are satisfied.
1.7≤x≤2.2
0.8≤y≤1.3
1≤α≤2.5
0.5≤β≤2