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.

A continuous hydrothermal process for producing LFP/LMFP cathode materials for lithium-ion batteries. The reactant solutions include: (1) a lithium precursor (LiOH) and a carbon source (15 wt % sucrose); (2) an iron precursor (FeSO.sub.4) and a phosphorus precursor (H.sub.3PO.sub.4); and in the case of LMFP, a manganese precursor (MnSO.sub.4) and a surfactant in solution 2. Reactant solutions are fed into a series of one or more continuous stirred tank reactors (CSTRs) at a constant flowrate. Active LFP/LMFP flows out of the CSTRs and into a collection tank, where it is cooled and depressurized. The product flows into a slurry tank, then a centrifugal separator to remove aqueous waste. The LFP/LMFP is transferred to a continuous rotary kiln for drying and sintering, and the carbon coating forms. The disclosed processes produce LFP/LMFP with small average particle size, high purity, high capacity, and high yield without any ball-milling or sieving steps.

Disclosed are a metal carbide catalyst composite for abifunctional zinc-air battery, which contains both vanadium metal and heterogeneous transition metal, and a zinc-air battery system containing the same. According to an embodiment of the disclosure, a catalyst reaction area is increased by substituted iron and vanadium ions of the metal carbide catalyst composite for the zinc-air battery, thereby exhibiting high activity for ORR performance as well as OER performance.

Additionally, an embodiment of the present invention provides a material for a positive electrode active material for secondary batteries and a method for manufacturing a material for a positive active material for secondary batteries. In detail, it provides a material for secondary battery positive electrode active material and a method of manufacturing a material for secondary battery positive electrode active material that can utilize a carbon-coated iron-vanadium metal oxide structure as a secondary battery positive active material.

According to one embodiment, there is provided an active material. The active material includes a composite oxide. The composite oxide has a monoclinic crystal structure. The composite oxide is represented by a general formula of Li.sub.wNa.sub.4-xM1.sub.yTi.sub.6-zM2.sub.zO.sub.14+. In the general formula, the M1 is at least one element selected from the group consisting of Rb, Cs, K and H; the M2 is at least one metallic element selected from the group consisting of Zr, Sn, V, Nb, Ta, Mo, W, Fe, Co, Mn and Al; w is within a range of 0w<12; x is within a range of 0<x<4; y is within a range of 0y<2; z is within a range of 0<z<6; and is within a range of 0.30.3.

A nitrogen oxide (NOx) reduction catalyst that includes a transition metal tungstate having the formula: MWO.sub.4 wherein M is selected from the group consisting of Mn, Fe, Co, Ni, and Cu. The catalyst may be utilized in various environments including oxygen rich and oxygen deficient environments.

A method for manufacturing a zinc ferrite film includes forming a zinc ferrite film on a base material by having a reaction liquid, which contains metal ions including only bivalent iron ions and bivalent zinc ions, contact an oxidation liquid, which contains an oxidant that oxidizes the metal ions, in the presence of a pH adjuster. The pH adjuster includes a carbonate of ammonium and an alkali metal salt of mono-carboxylic acid.

A method for efficiently preparing ferrate based on nascent state interfacial activity. The method is as follows: (a) preparing nascent iron solution; (b) adding an oxidizing agent to the iron solution of step (a); (c) adding alkali solution or alkali particles to the mixed solution of step (b), mixing by stirring, and carrying out solid-liquid separation; (d) adding a stabilizing agent to the liquid separated out in step (c), and thus obtaining ferrate solution. The yield is 78-98%. The prepared ferrate solution is stable and can be stored for 3-15 days.

The main object is to provide a novel material with excellent charge and discharge characteristics, such as a high utilization rate of a positive electrode, a high capacity, and good cycle characteristic, in which the material is a compound containing as the major component lithium sulfide useful as a cathode active material for lithium secondary batteries. The invention provides a lithium sulfide-iron-carbon composite containing lithium, iron, sulfur and carbon as constituent elements, with lithium sulfide (Li.sub.2S), as the main phase, having a crystallite size of 50 nm or less as calculated from the half width of the diffraction peak based on the (111) plane of Li.sub.2S as determined by X-ray powder diffraction.

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.