This invention provides a method for efficiently separating magnesium and lithium from salt lake brine, and simultaneously preparing high-purity magnesium oxide and battery-grade lithium carbonate. The detailed processing steps are as follows: (1) adding urea into the brine to dissolve, (2) placing the solution into the reactor for hydrothermal reaction, the magnesium ion will precipitate and enter the solid phase; (3) filtering and drying the production to get the magnesium carbonate solid, while the lithium ion remains in the liquid phase; (4) after directly concentration and precipitation, the battery-grade lithium carbonate can be obtained, while the calcination of solid-phase product results in the high-purity magnesium oxide. In this method, urea is used as the precipitant to separate magnesium and lithium in salt lake without introducing any new metal ion, and the brine solution is not diluted. The solid product is white and fluffy powder, which is easy to filter and separate. The extraction rate of lithium is high than 94%, and the purity of MgO obtained by calcination is higher than 99.5%.

A sparsely pillared organic-inorganic hybrid compound is provided. The sparsely pillared organic-inorganic hybrid compound includes: two inorganic material layers, each extending in one direction and facing each other; and an organic material layer disposed between the two inorganic material layers, wherein each of the inorganic material layers has a gibbsite structure in which a divalent metal cation is doped to an octahedral site, and the organic material layer includes a plurality of pillar portions, each of which is chemically bound to each of the two inorganic material layers such that the two inorganic material layers are connected to each other.

A method of rapid treatment of heavy metal sludge and preparation of ferrite magnets comprises following steps of: providing a sludge, the sludge at least having zinc metal and ferrous metal; adding an iron-containing substance to the sludge; pickling the sludge and the iron-containing substance with sulfuric acid to obtain a pickling solution with zinc ions and iron ions; neutralizing the pickling solution with sodium hydroxide to form hydroxide precipitates; and airing and heating the neutralized pickling solution by an ultrasonic-microwave method so that the hydroxide precipitates undergoing a ferrite magnet reaction, thereby obtaining ferrite magnets with a spathic structure.

A film-forming material of the present invention contains an oxyfluoride of yttrium represented by YOF.sub.Y (X and Y are numbers satisfying 0<X and X<Y) and YF.sub.3, wherein a ratio I.sub.2/I.sub.1 of a peak height I.sub.2 of the (020) plane of YF.sub.3 to a peak height I.sub.1 of the main peak of YO.sub.XF.sub.Y as analyzed by XRD is from 0.005 to 100. It is preferable that a ratio I.sub.4/I.sub.1 of a peak height I.sub.4 of the main peak of Y.sub.2O.sub.3 to the peak height I.sub.1 of the main peak of YO.sub.XF.sub.Y as analyzed by XRD is 0.01 or less.

The present disclosure discloses a lithium-manganese rich material and a preparation method and a use thereof.

The present disclosure provides a cobalt-free cathode material of a lithium ion battery, a method for preparing the cobalt-free cathode material, and the lithium ion battery. A general formula of the cobalt-free cathode material is Li.sub.xNi.sub.aMn.sub.bR.sub.cO.sub.2, wherein, 1≤x≤1.15, 0.5≤a≤0.95, 0.02≤b≤0.48, 0<c≤0.05, and R is aluminum or tungsten. Therefore, as the cobalt-free cathode material is free of metal cobalt, the cost of the cathode material can be lowered effectively. Aluminum or tungsten in the cobalt-free cathode material can stabilize a crystal structure of the cathode material better, such that the lithium ion battery has excellent rate capability and cycle performance, and furthermore, good cycling stability of the lithium ion battery can be still maintained under a high-temperature and high-pressure testing condition.

Dy.sub.2O.sub.3 particles of a nanoparticle scale have beneficial properties for ceramic and electronic uses. Disclosed herein are moderately dispersed Dy.sub.2O.sub.3 particles having regular morphology and lateral size ranging from about 10 nm to 1 μm. The Dy.sub.2O.sub.3 particles may exhibit a narrow particle size distribution such that the difference between D.sub.10 and D.sub.90 is about 0.1 μm to 1 μm. Further disclosed are processes of producing these moderately dispersed Dy.sub.2O.sub.3 particles. These processes do not include grinding to obtain the particles. Also disclosed herein are uses for these Dy.sub.2O.sub.3μ particles.

A lithium battery positive active material precursor, a preparation method therefor and the use thereof are provided. The precursor has a chemical formula of Ni.sub.xCo.sub.yM.sub.z(OH).sub.2, wherein M is at least one metal selected from the group consisting of Fe, Cr, Cu, Ti, Mg, W, Mo, Nb, Zn, Sn, Zr, Ga, Mn and Al, 0.3≤x≤1, 0<y≤0.5, 0<z≤0.3; and the precursor comprises aggregates of platy monocrystals and polyhedral monocrystal particles. In the XRD pattern of the precursor, I(001), I(100) and I(101) satisfy the following relationship: I(001)/I(100) is not less than about 1.5, and I(001)/I(101) is not less than about 1.2.

The present invention comprises, in lithium composite oxide particles, an overlithiated oxide having a layered crystal structure and represented by chemical formula 1 below, and comprises a lithium manganese oxide represented by chemical formula 2 below outside the lithium composite oxide particles, wherein the overlithiated oxide included in the particles and the lithium manganese oxide included outside the particles have different Li/IM values. [Chemical formula 1] rLi.sub.2MnO.sub.3.(1-r)Li.sub.aNi.sub.xCo.sub.yMn.sub.zM1.sub.1-(x+y+z)O.sub.2 (wherein, in chemical formula 1, 0<r≤0.6, 0<a≤1, 0≤x≤1, 0≤y<1, 0≤z<1, and 0<x+y+z≤1, and M1 is at least any one selected from Na, K, Mg, Al, Fe, Cr, Y, Sn, Ti, B, P, Zr, Ru, Nb, W, Ba, Sr, La, Ga, Mg, Gd, Sin, Ca, Ce, Fe, Al, Ta, Mo, Se, Zn, Nb, Cu, in, S, B, and Bi) [Chemical formula 2] Li.sub.bMn.sub.pO.sub.q (wherein, in chemical formula 2, 0.1≤b/p≤2.5 and 0<q≤15).

The present invention comprises: an overlithiated layered oxide represented by chemical formula 1 below; and an ion-conductive coating layer on the overlithiated layered oxide represented by chemical formula 1: [chemical formula 1] .sub.rLi.sub.2MnO.sub.3.Math.(1-r)Li.sub.aNi.sub.xCo.sub.yMn.sub.zM1.sub.1−(x+y+z)O.sub.2 (in chemical formula 1, 0<r≤0.6, 0<a≤1, 0≤x≤1, 0≤y<1, 0≤z<1, and 0<x+y+z<1, and M1 is at least one selected from among Na, K, Mg, Al, Fe, Cr, Y, Sn, Ti, B, P, Zr, Ru, Nb, W, Ba, Sr, La, Ga, Mg, Gd, Sm, Ca, Ce, Fe, Al, Ta, Mo, Sc, V, Zn, Cu, In, S, B, Ge, Si, and Bi).