A positive electrode active material for a non-aqueous electrolyte secondary battery according to an aspect of the present disclosure contains a lithium metal composite oxide having secondary particles formed by the aggregation of primary particles, wherein W is present on the surface and inside of the secondary particles of the lithium metal composite oxide. The amount of W present on the surface of the secondary particles of the lithium metal composite oxide represented by general formula LiαNiaCobAlcMdWeOβ (in the formula, 0.9≤α≤1.2, 0.8≤a≤0.96, 0<b≤0.10, 0<c≤0.10, 0≤d≤0.1, 0.0003≤e/(a+b+c+d+e)≤0.002, 1.9≤β≤2.1, a+b+c+d=1, and M is at least one element selected from among Mn, Fe, Ti, Si, Nb, Zr, Mo, and Zn) is 25-45% of the total amount of W present on the surface and inside of the secondary particles of the lithium metal composite oxide.

The present invention pertains to: a positive electrode active material precursor containing first secondary particle composed of an aggregate of a plurality of first primary particles, the positive electrode active material precursor including a first center portion represented by chemical formula 1 and a first surface portion represented by chemical formula 2, wherein the thickness of the first surface portion is 2-20% of the average radius of the positive electrode active material precursor; and a positive electrode active material containing the positive electrode active material precursor.

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.

The present invention relates to a lithium composite oxide having improved stability and electrical characteristics as a positive electrode material by inhibiting an interfacial side reaction in the lithium composite oxide and improving the stability of a crystal structure and ion conductivity, and a lithium secondary battery including the same.

A nickel-based active material for a lithium secondary battery, a method of preparing the nickel-based active material, and a lithium secondary battery including a positive electrode including the nickel-based active material, the nickel-based active material comprising a secondary particle having an outer portion with a radially arranged structure and an inner portion with an irregular porous structure, wherein the inner portion of the secondary particle has a larger pore size than the outer portion of the secondary particle.

A process for preparing a metal hydroxide comprising (i) at least one metal chosen from nickel and cobalt and optionally (ii) at least one metal chosen from manganese, lithium and aluminum. The process comprises: reacting a metal sulfate comprising (i) at least one metal chosen from nickel and cobalt and optionally (iii) at least one metal chosen from manganese and aluminum with sodium hydroxide and optionally a chelating agent in order to obtain a solid comprising the metal hydroxide and a liquid comprising sodium sulfate; separating the liquid and the solid from one another to obtain the metal hydroxide; submitting the liquid comprising sodium sulfate to an electromembrane process for converting the sodium sulfate into sodium hydroxide; and reusing the sodium hydroxide obtained by the electromembrane process for reacting with the metal sulfate.

Provided is a high-entropy positive electrode material, preparation method and application thereof. The high-entropy positive electrode material has a general formula as shown in the following formula: Li.sub.1+aA.sub.xB.sub.yC.sub.zD.sub.bO.sub.2M.sub.cN.sub.d, wherein A is a metallic element having a valence of +2, B is a metallic element having a valence of +3, C is a metallic element having a valence of +4, D is a metallic element having a valence of +5, M is an element having a valence of +7, and N is an element having a valence of +8; and 0≤a<1, 0<x<1, 0<y<1, 0<z<1, 0<b<1, 0<c<1, d>0. This high-entropy positive electrode material is designed from the structure of the material itself. Compared with the conventional positive electrode materials, it has high specific discharge capacity and has a stable structure during the cycling without oxygen evolution.

A positive active material for a nonaqueous electrolyte energy storage device according to one aspect of the present invention is a positive active material for a nonaqueous electrolyte energy storage device containing a lithium transition metal composite oxide having an α-NaFeO.sub.2 structure, the positive active material further containing aluminum, in which the lithium transition metal composite oxide contains at least one of nickel and cobalt, and manganese, a content of manganese in a transition metal. in the lithium transition metal composite oxide is 0.6 or less in terms of molar ratio, and in a charged state at a potential of 4.35 V vs. Li/Li.sup.+ in a state where there is no charge history in which the potential reaches 4.5 V vs. Li/Li.sup.+ or more, an oxygen positional parameter of the positive active material determined from crystal structure analysis by a Rietveld method when a space group R3-m is used. for a crystal structure model based on an X-ray diffraction pattern is 0.265 or more and 0.269 or less.

A positive electrode active material precursor for a lithium secondary battery containing at least Ni, in which S/D.sub.50 that is a ratio of a BET specific surface area S to a 50% cumulative volume particle size D.sub.50 is 2×10 to 20×10.sup.6 m/g, and, in powder X-ray diffraction measurement using a CuKα ray, A/B that is a ratio of an integrated intensity A of a diffraction peak within a range of 2θ=37.5±1° to an integrated intensity B of a diffraction peak within a range of 2θ=62.8±1° is more than 0.80 and 1.33 or less.

The disclosure provides a modified positive electrode material, a preparation method therefor, and a lithium ion battery. The modified positive electrode material includes a core and a coating layer. The core contains Mn and Ni, the coating layer includes a first oxide coating layer coating on a surface of the core. A first element forming the first oxide coating layer is selected from one or more of a group of Si, Ti, V, Zr, Mo, W, Bi, Nb, and Au. The first element with a high-valent state can partially enter the surface core structure of the positive electrode material to occupy the sites of manganese ions, and form a chemical bond stronger than a Mn—O. Thus, 0 and Mn in the core structure are difficult to precipitate, and the coating layer is difficult to fall off in cycle process. Moreover, structural stability of the modified positive electrode material is improved.