A sodium-containing oxide positive electrode material and a preparation method therefor and use thereof are disclosed. Also disclosed are a positive electrode plate and uses thereof.

Disclosed are a functional material for synchronously stabilizing multiple metals and a preparation method thereof, and a method for rehabilitating soil or wastewater contaminated by heavy metals (metalloids). The preparation method includes: mixing a ferrous salt, a ferric salt, a manganous salt, water, a dispersing material, and a phosphate to obtain a first mixture, and subjecting the first mixture to a first precipitation reaction to obtain a first reaction mixture containing the phosphate; adjusting a pH value of the first reaction mixture containing the phosphate to 10-12 by adding an alkali thereto to obtain a second mixture, subjecting the second mixture to a second precipitation reaction to obtain a second reaction mixture; and subjecting the second reaction mixture to a solid-liquid separation to obtain a solid, washing the solid, and drying to obtain the functional material for synchronously stabilizing multiple metals.

The present invention discloses a mesoporous manganese ferrite Fenton-like catalyst and preparation method and application thereof and pertains to the field of preparation of Fenton-like catalysts. The present invention uses KIT-6 as a hard template agent to synthesize mesoporous manganese ferrite catalyst. The prepared mesoporous manganese ferrite and hydrogen peroxide constitute a Fenton-like system oxidation wastewater treatment system to carry out efficient removal and mineralization of organic pollutants in wastewater. The preparation method of the present invention is simple and efficient. The prepared Fenton-like catalyst has a mesoporous structure and a relatively large specific surface area. It can provide more adsorption sites and catalytic site and efficiently degrade pollutants in a wide pH range (acidic, neutral and even alkaline) and solves the problem that conventional Fenton reaction occurs only under an acidic condition and a large amount of iron sludge is generated during reaction, causing secondary pollution. Further, the catalyst can be used cyclically and easily separated from the water solution and recovered after use.

A sodium-based electrode active material and a secondary battery comprising the same are provided. The electrode active material is represented by the following Chemical Formula 1, and has an orthorhombic crystal system and a space group of Cmcm. [Chemical Formula 1] Na.sub.x[Mn.sub.1-y-zM.sup.1.sub.yM.sup.2.sub.z]O.sub.2-A.sub.. In Chemical Formula 1, x may be 0.5 to 0.8. M.sup.1 and M.sup.2 may be, regardless of each other, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nd, Mo, Tc, Ru, Rh, Pd, Pb, Ag, Cd, Al, Ga, In, Sn, or Bi. y may be from 0 to 0.25. z may be from 0 to 0.25. A may be N, O, F, or S, and a may be 0 to 0.1.

The present invention relates to a method for producing a positive electrode material comprising at least one Na-based solid crystalline phase selected in the group consisting of Na-based crystalline P2-phases, Na-based solid crystalline phases of formula Na.sub.(3+x)V.sub.2(PO.sub.4).sub.3 with 0<x3 and Na-based solid crystalline phases of formula Na.sub.(3+y)V.sub.2(PO.sub.4).sub.2F.sub.3 with 0<y3, for a battery using sodium ions as electrochemical vector, said method using a ball milling process involving Na.sub.3P as starting material.

An object of the present invention is to provide ferrite particles having a high saturation magnetisation, and being excellent in the dispersibility in a resin, a solvent or a resin composition, a resin composition including the ferrite particles, and a resin film composed of the resin composition. The ferrite particles are a single crystalline body having an average particle size of 1 to 2000 nm, and Mn-based ferrite particles having a spherical shape, and have a saturation magnetisation of 45 to 95 Am.sup.2/kg. The resin composition includes the ferrite particles as a filler. The resin film is composed of the resin composition.

Provided are a ferrite powder that inhibits magnetic loss at frequencies lower than 100 MHZ, and when applied to a composite material or a composite body, is capable of preventing particles from coming off without loss of moldability and filling properties, a ferrite resin composite material, and electromagnetic shielding material, electronic material, or electronic component. This ferrite powder is a MnZn ferrite powder containing at least spherical or polyhedral ferrite particles having a spinel phase as a main phase. The ferrite particles also have, at respective surfaces thereof, a step structure having a convex polygonal contour. Furthermore, the BET specific surface area of the ferrite powder is 0.35-10.00 m.sup.2/g, and the contained amount of the zinc oxide (ZnO) phase thereof is 0-0.8 mass %.

A sodium-containing oxide positive electrode material and a preparation method therefor and use thereof are disclosed. Also disclosed are a positive electrode plate and uses thereof.

Ferrite powder of the present invention is ferrite powder detectable with a metal detector, comprising: soft ferrite particles containing Mn of 3.5 mass % or more and 20.0 mass % or less and Fe of 50.0 mass % or more and 70.0 mass % or less. It is preferable that a volume average particle diameter of the particles constituting the ferrite powder is 0.1 m or more and 100 m or less. It is preferable that magnetization by a VSM measurement when magnetic field of 5 K.Math.1000/4A/m is applied is 85 A.Math.m.sup.2/kg or more and 98 A.Math.m.sup.2/kg or less.

A positive electrode for a sodium ion secondary battery includes a positive electrode active material that intercalates and deintercalates sodium ions, a conductive assistant, a binder, and a carboxylic acid, the binder containing a vinylidene fluoride-based polymer, the carboxylic acid having at least one of a boiling point and a thermal decomposition point, and whichever of the boiling point and the thermal decomposition point is lower being higher than 150 C. The carboxylic acid is preferably at least one selected from the group consisting of hydroxy acids and polycarboxylic acids.