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.

A battery comprising an acidified metal oxide (“AMO”) material, preferably in monodisperse nanoparticulate form 20 nm or less in size, having a pH <7 when suspended in a 5 wt % aqueous solution and a Hammett function H.sub.0 >−12, at least on its surface.

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. $\begin{array}{cc}0<\frac{\mathrm{Tap}\mathrm{density}}{\begin{array}{c}\mathrm{Average}\mathrm{particle}\mathrm{diameter}D50\\ \mathrm{of}\mathrm{transition}\mathrm{of}\mathrm{metal}\mathrm{precursor}\end{array}}<3500\left(g/\mathrm{cc}.Math.\mathrm{cm}\right)& \left(1\right)\end{array}$

In one embodiment, a positive electrode active material for a secondary battery, the positive electrode active material being a primary particle having a monolithic structure that includes a lithium composite metal oxide of Formula 1 below, wherein the primary particle has an average particle size (D.sub.50) of 2 μm to 20 μm and a Brunauer-Emmett-Teller (BET) specific surface area of 0.15 m.sup.2/g to 0.5 m.sup.2/g, and wherein the positive electrode active material has a rolling density of 3.0 g/cc or higher under a pressure of 2 ton.Math.f:
Li.sub.aNi.sub.1-x-yCo.sub.xM1.sub.yM3.sub.zM2.sub.wO.sub.2  [Formula 1] in Formula 1, M1 is at least one selected from the group consisting of Al and Mn, M2 is any one or two or more elements selected from the group consisting of Zr, Ti, Mg, Ta, and Nb, M3 is any one or two or more elements selected from the group consisting of W, Mo, and Cr, and 1.0≤a≤1.5, 0≤x≤0.5, 0≤y≤0.5, 0.005≤z≤0.01, 0≤w≤0.04, 0<x+y≤0.7.

A secondary battery with favorable cycle performance is provided. Alternatively, a secondary battery with higher capacity is provided. A positive electrode active material layer including a first graphene layer, a second graphene layer, and a positive electrode active material. The first graphene layer includes a first region covering the positive electrode active material. The second graphene layer includes a second region covering the positive electrode active material and a third region overlapping with the first region. The first region includes a plane positioned between the positive electrode active material and the third region and formed of arranged six-membered carbon rings. The positive electrode active material includes a fourth region with a layered rock-salt structure. A lithium layer with a layered rock-salt structure included in the fourth region is substantially perpendicular to the plane formed of six-membered carbon rings and included in the second region.

A solid electrolyte material according to the present disclosure includes Li, DC, Y, Sm, and X. The DC is at least one selected from the group consisting of Mg, Ca, Sr, Ba, and Zn. The X is at least one selected from the group consisting of F, Cl, Br, and I. A battery according to the present disclosure includes a positive electrode, a negative electrode, and an electrolyte layer provided between the positive electrode and the negative electrode. At least one selected from the group consisting of the positive electrode, the negative electrode, and the electrolyte layer includes the solid electrolyte material according to the present disclosure.

There is provided a sulfide solid electrolyte containing elemental lithium (Li), elemental phosphorus (P), elemental sulfur (S), and an elemental halogen (X). The mole ratio of the elemental lithium (Li) to the elemental phosphorus (P), Li/P, satisfies 3.7<Li/P<5.4. The mole ratio of the elemental sulfur (S) to the elemental phosphorus (P), S/P, satisfies 3.9<S/P<4.1. The mole ratio of the elemental halogen (X) to the elemental phosphorus (P), X/P, satisfies 0.7<X/P<2.4. The sulfide solid electrolyte includes a crystalline phase having an argyrodite-type crystal structure.

A producing method according to the present disclosure includes heat-treating a material mixture at higher than or equal to 150° C. and lower than or equal to 450° C., wherein the material mixture contains MX.sub.5 and at least one selected from the group consisting of Li.sub.2O.sub.2, Li.sub.2O, and LiOH, M is at least one selected from the group consisting of Ta and Nb, and X is at least one selected from the group consisting of Cl and Br.

In an aspect, a mixed metal oxide comprises or consists essentially of: a mixture comprises or consisting essentially of 0.30 to 0.69 parts by mole Mg, 0.20 to 0.69 parts by mole Zn, 0.01 to 0.30 parts by mole of a third element selected from Al and Ga, and, either, when the third element is Al, 0.00 to 0.31 parts by mole of other elements selected from metals and metalloids, or, when the third element is Ga, 0.00 to 0.15 parts by mole of other elements selected from metals and metalloids, wherein the sum of all parts by mole of Mg, Zn, the third element, and the other elements amounts to 1.00, wherein the amount in parts by mole of the other elements is lower than the amount in parts by mole of Mg and is lower than the amount in parts by mole of Zn; oxygen; and less than 0.01 parts by mole of non-metallic and non-metalloid impurities.

An object of the present invention is to provide ferrite particles for supporting a catalyst having a small apparent density, various properties are maintained in a controllable state and a specified volume is filled with a small weight, and a catalyst using the ferrite particles for supporting a catalyst. To achieve the object, ferrite particles for supporting a catalyst provided with an outer shell structure containing Ti oxide, a catalyst using the ferrite particles for supporting a catalyst are employed.