A positive electrode active material that can achieve high thermal stability at low cost is provided.

Provided is a positive electrode active material for a lithium ion secondary battery, the positive electrode active material containing a lithium-nickel-manganese composite oxide, in which metal elements constituting the lithium-nickel-manganese composite oxide include lithium (Li), nickel (Ni), manganese (Mn), cobalt (Co), titanium (Ti), niobium (Nb), and optionally zirconium (Zr), an amount of substance ratio of the elements is represented as Li:Ni:Mn:Co:Zr:Ti:Nb=a:b:c:d:e:f:g (provided that, 0.97≤a≤1.10, 0.80≤b≤0.88, 0.04≤c≤0.12, 0.04≤d≤0.10, 0≤e≤0.004, 0.003<f≤0.030, 0.001<g≤0.006, and b+c+d+e+f+g=1), in the amount of substance ratio, (f÷g)≤0.030 and f>g are satisfied, and an amount of lithium to be eluted in water when the positive electrode active material is immersed in water is 0.20% by mass or less with respect to the entire positive electrode active material.

The method for producing a positive electrode active material for a lithium ion secondary battery includes preparing a mixture containing at least a nickel-manganese composite compound, a lithium compound, and optionally one or both of a titanium compound and a niobium compound. The method also includes firing the mixture from 750° C. to 1000° C. so as to obtain the lithium-nickel-manganese composite oxide, in which the nickel-manganese composite compound contains at least nickel, manganese, and an element M, an amount of substance ratio (z) of titanium and an amount of substance ratio (w) of niobium to a total amount of substance of nickel, manganese, the element M, titanium, and niobium in the mixture satisfy 0.005≤z≤0.05, 0.001<w≤0.03, (z+w)≤0.06, and z>w, and at least a part of the niobium is segregated to a grain boundary between primary particles.

A method of fabricating a positive active material for a rechargeable sodium battery is provided. The method includes forming a metal hydroxide precursor including nickel, cobalt, and manganese, and fabricating a positive active material by mixing and firing the metal hydroxide precursor and a sodium source. A kind of the sodium source is changed depending on a content of nickel or manganese included in the metal hydroxide precursor.

Process for making a particulate (oxy)hydroxide of TM wherein TM comprises nickel wherein said process comprises the steps of: (a) Providing an aqueous solution (α) containing water-soluble salts of Ni and of at least one transition metal selected from Co and Mn, and, optionally, at least one further metal selected from Ti, Zr, Mo, W, Al, Mg, Nb, and Ta, and an aqueous solution (β) containing an alkali metal hydroxide and, optionally, an aqueous solution (γ) containing ammonia, (b) combining a solution (α) and a solution (β) and, if applicable, a solution (γ) at a pH value in the range of from 12.0 to 13.0, thereby creating solid particles of hydroxide containing nickel, (c) continuing combining solutions (α) and (β) and, if applicable, (γ) at a pH value in the range of from 9.0 to 12.0 and in any way below the pH value in step (b), (d) adding a solution (α) and a solution (β) and, if applicable, a solution (γ) at a pH value in the range of from 12.0 to 12.7 and in any way above the pH value in step (c), (e) continuing combining such solutions (α) and (β) and, if applicable, (γ) at a pH value in the range of from 9.0 to 12.0 and in any way below the pH value in step (d), wherein step (d) has a duration in the range of from rt-0.01 to rt-0.15 and wherein it is the average residence time of the reactor in which steps (b) to (e) are carried out.

A positive electrode active material of the present invention comprising a composite oxide containing Li and Ni, and optionally containing at least one element other than Li and Ni, is characterized in one of the following: primary particles constituting each of secondary particles of the composite oxide and having a variation coefficient of span of 17% or less, the span being a formula: (D.sub.190−D.sub.110)/D.sub.150 (D.sub.110, D.sub.150, D.sub.190: particle diameter corresponding to 10%, 50%, 90% of an integrated value in a number standard-particle diameter distribution of primary particle size); the primary particles having a variation coefficient of D.sub.150 of 19% or less; and the secondary particles having each of values of 1.00% or less, the values being formulae: |[ER1−ER21)/ER1]|×100, |[ER1−ER22)/ER1]|×100, |[ER1−ER23)/ER1]|×100 (ER1, ER21, ER22, ER23: element ratio (Li/(Ni+Other element(s))) of entire secondary particles, small particles, middle particles, large particles).

Systems and methods for direct recycling and upcycling of spent cathode materials using Flame-Assisted Spray Pyrolysis Technology (FAST). In illustrative embodiments, cathode layers are separated and collected from spent battery cells. The cathode laminate is ground to a powdered form and treated to remove contaminants by sifting into a hot stream of air which heats the powders, burning off contaminants. After cooling and particle collection, the powders may be dispersed into leaching solution to dissolve metal oxides and create an acid metal solution or ground into nano-sized primary particles and mixed with dispersing liquids to form a solution. The solution may be mixed with glycerol and additional metal salts to create a final precursor solution, which may undergo spray pyrolysis followed by drying and calcination to create cathode materials with high consistency and repeatability, or mixed with an alkaline metal salt solution and undergo electrodeposition to recover desired metal salts.

A nickel lithium ion battery positive electrode material having a concentration gradient, and a preparation method therefor. The material is a core-shell material having a concentration gradient, the core material is a material having a high content of nickel, and the shell material is a ternary material having a low content of nickel. The method comprises: synthesizing a material precursor having a high content of nickel by means of co-precipitation, co-precipitating a ternary material solution having a low content of nickel outside the material precursor having a high content of nickel, aging, washing, and drying to form a composite precursor in which the low nickel material coats the high nickel material, adding a lithium source, grinding, mixing, calcining, and cooling to prepare a high nickel lithium ion battery positive electrode material. The obtained material has regular morphology, uniform coating, narrow particle size distribution range, gradient distribution of the concentration of the nickel element, high content of the nickel element in the core, and low content of the nickel element in the shell; the nickel element in the core guarantees the specific capacity of the material, and the shell coating material maintains the stability of the structure of the material, so as to improve the safety of the material in the charge and discharge process, and improve the cycle and rate performance of the material.

A positive electrode material for a lithium-ion secondary battery which has high capacity and excellent charge and discharge cycle performance, and a manufacturing method thereof are provided, or a method of manufacturing a positive electrode material with high productivity is provided. The positive electrode material for a lithium-ion secondary battery includes a crystal represented by a crystal structure with a space group R-3m, a first region, and a second region, which is in contact with at least part of an outer side of the first region and whose outer edge corresponds to a surface of the first particle. The ratio of manganese atoms to cobalt atoms in the first region is lower than the ratio of manganese atoms to cobalt atoms in the second region. The ratio of fluorine atoms to oxygen atoms in the first region is lower than the ratio of fluorine atoms to oxygen atoms in the second region.

A Ni-rich ternary cathode material, a preparation method and application thereof are disclosed. The method for preparing a Ni-rich ternary cathode material includes: using a Ni—Co—Mn ternary cathode material as a precursor and a metal boride as a modifier, adding a lithium-derived material, heating for a sintering, to prepare the Ni-rich ternary cathode material.

A method for producing a M-carbonate precursor of a Li-M oxide cathode material in a continuous reactor, wherein M=NixMnyCozAn, A being a dopant, with x>0, y>0, 0≦z≦0.35, 0≦n≦0.02 and x+y+z+n=1, the method comprising the steps of: —providing a feed solution comprising Ni-, Mn-, Co- and A-ions, and having a molar metal content M″ feed, —providing an ionic solution comprising either one or both of a carbonate and a bicarbonate solution, the ionic solution further comprising either one or both of Na- and K-ions, —providing a slurry comprising seeds comprising M′-ions and having a molar metal content M′ seeds, wherein M′=Nix′Mny′Coz′A′n′, A′ being a dopant, with 0≦x′≦1, 0≦y′≦1, 0≦z′≦1, 0≦n′≦1 and x′+y′+z′+n′=1, and wherein the molar ratio M′ seeds/M″ feed is between 0.001 and 0.1, —mixing the feed solution, the ionic solution and the slurry in the reactor, thereby obtaining a reactive liquid mixture, —precipitating a carbonate onto the seeds in the reactive liquid mixture, thereby obtaining a reacted liquid mixture and the M-carbonate precursor, and —separating the M-carbonate precursor from the reacted liquid mixture.