A cobalt-free layered positive electrode material, a preparation method thereof, and a lithium-ion battery are provided. The method includes: preparing a layered lithium nickel manganese oxide matrix material; mixing the layered lithium nickel manganese oxide matrix material with a coating agent to obtain a first mixed material; and forming a coating layer on a surface of the layered lithium nickel manganese oxide matrix material by performing a first sintering treatment on the first mixed material to obtain the cobalt-free layered positive electrode material. The coating agent includes a first coating agent including ceramic oxide, and a second coating agent including at least one of phosphate and silicate.

A mixed powder for an all-solid-state lithium-ion battery, which is composed of a positive electrode active material for a lithium-ion battery and a solid electrolyte, wherein the positive electrode active material for a lithium-ion battery is composed of particles containing crystals of a lithium metal composite oxide, and the lithium metal composite oxide has a layered structure and contains at least Li and a transition metal, wherein the positive electrode active material for a lithium-ion battery has a particle diameter distribution that satisfies the following Formula (1), and wherein the solid electrolyte has a particle diameter distribution that satisfies the following Formula (2):

[00001]$\left(\text{D90-D10}\right)/\text{D50}\le \text{1}\text{.5}$

[00002]$\left(\text{D90-D10}\right)/\text{D50}\le 2.0$

A positive electrode material and a preparation method therefor, a lithium-ion battery, and an electric vehicle. The positive electrode material comprises: matrix particles, materials forming the matrix particles comprising at least one of a lithium-rich manganese-based material, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium iron phosphate, lithium manganate, lithium nickel cobalt manganese aluminate, and lithium nickel manganate; and a housing, the housing covering at least a portion of the outer surfaces of the matrix particles.

What is claimed is a positive electrode active material for an all-solid-state lithium-ion battery composed of particles containing crystals of a lithium metal composite oxide,

wherein the lithium metal composite oxide has a layered structure and contains at least Li and a transition metal, and wherein, in the particles, in pore physical properties obtained from nitrogen adsorption isotherm measurement and nitrogen desorption isotherm measurement at a liquid nitrogen temperature, the total pore volume obtained from a nitrogen adsorption amount when the relative pressure (p/p.sub.0) of an adsorption isotherm is 0.99 is less than 0.0035 cm.sup.3/g.

This positive electrode active substance for a non-aqueous electrolyte secondary battery contains a lithium-transition metal composite oxide which has a crystal structure belonging to the space group Fm-3m and is represented by the compositional formula Li.sub.xMn.sub.yM.sub.aO.sub.bF.sub.c (in the formula: M is at least one type of metal element excluding Mn; x+y+a=b+c=2; 1<x≤1.35; 0.4≤y≤0.9; 0≤a≤0.2; and 1.3≤b≤1.8). In addition, the lattice constant a of the lithium-transition metal composite oxide is 4.09-4.16.

A secondary battery includes a positive electrode, a negative electrode, and an electrolytic solution. The positive electrode includes a positive electrode active material layer. The positive electrode active material layer includes a lithium-nickel composite oxide of a layered rock-salt type.

There is provided a method for collecting and reusing an active material from positive electrode scrap. The method of reusing a positive electrode active material of the present disclosure includes (a-1) immersing a positive electrode scrap comprising an active material layer on a current collector into a basic solution to separate the active material layer from the current collector, (a-2) thermally treating the active material layer in air for thermal decomposition of a binder and a conductive material in the active material layer, and collecting an active material in the active material layer, (b) washing the active material collected from the step (a-2) with a lithium compound solution which is basic in an aqueous solution and drying, and (c) annealing the active material washed from the step (b) with a lithium precursor to obtain a reusable active material.

A lithium transition metal oxide electrode including an additional metal is provided herein as well electrochemical cells including the lithium transition metal oxide electrode and methods of making the lithium transition metal oxide electrode. The lithium transition metal oxide electrode includes a first electroactive material including Li.sub.1+aNi.sub.bMn.sub.cM.sub.dO.sub.2, where 0.05≤a≤0.6; 0.01≤b≤0.5; 0.1≤c≤0.9; zero (0)≤d≤0.3; b+c+d=1 or a+b+c+d=1; and M represents an additional metal, such as W, Mo, V, Zr, Nb, Ta, Fe, Al, Mg, Si, or a combination thereof.

A positive-electrode material for a lithium ion secondary battery contains a lithium complex compound that is represented by the formula: Li.sub.1+aNi.sub.bMn.sub.cCo.sub.dTi.sub.eM.sub.fO.sub.2+α, and has an atomic ratio Ti.sup.3+/Ti.sup.4+ between Ti.sup.3+ and Ti.sup.4+, as determined through X-ray photoelectron spectroscopy, of greater than or equal to 1.5 and less than or equal to 20. In the formula, M is at least one element selected from the group consisting of Mg, Al, Zr, Mo, and Nb, and a, b, c, d, e, f, and a are numbers satisfying −0.1≤a≤0.2, 0.7<b≤0.9, 0≤c<0.3, 0≤d<0.3, 0<e≤0.25, 0≤f<0.3, b+c+d+e+f=1, and −0.2≤α≤0.2.

Disclosed are a transition metal precursor for preparation of a lithium transition metal oxide, in which a ratio of tap density of the precursor to average particle diameter D50 of the precursor satisfies the condition represented by Equation 1 below, and a lithium transition metal oxide prepared using the same. $\begin{array}{cc}0<\frac{\mathrm{Tap}\mathrm{density}}{\begin{array}{c}\mathrm{Average}\mathrm{particle}\mathrm{diameter}D50\\ \mathrm{of}\mathrm{transition}\mathrm{of}\mathrm{metal}\mathrm{precursor}\end{array}}<3500\left(g/\mathrm{cc}.Math.\mathrm{cm}\right)& \left(1\right)\end{array}$