A magnetic fiber comprises a core comprising a spinel ferrite of formula Me.sub.1-xM.sub.xFe.sub.yO.sub.4, wherein Me is Mg, Mn, Fe, Co, Ni, Cu, Zn, or a combination thereof, x=0 to 0.25, and y=1.5 to 2.5, wherein the core is solid or at least partially hollow; and a shell at least partially surrounding the core, and comprising a Me.sub.1-xM.sub.xFe.sub.y alloy, wherein when the core is solid with Me=Ni and x=0 the magnetic fiber has a diameter of greater than 0.3 micrometer. A magneto-dielectric material having a magnetic loss tangent of less than or equal to 0.03 at 1 GHz comprises a polymer matrix; and a plurality of the magnetic fibers.

The present disclosure relates to an anode electrode active material for a secondary battery containing nickel cobalt molybdenum oxide, an anode electrode for a secondary battery including the same, a secondary battery including the anode electrode for a secondary battery, and a method for manufacturing the same. The novel anode electrode material for a sodium secondary battery containing nickel cobalt molybdenum oxide according to the present disclosure allows intercalation/deintercalation reaction of sodium ion during charge/discharge and does not undergo significant volume change during the intercalation reaction because structure is maintained stably during repeated charge/discharge. As a result, electrode damage and electric short circuit are decreased and, thus, improved electrochemical characteristics can be achieved in long-life and high-rate capability.

When manufacturing a magnetic body which is made of a ferrite material containing Fe, Ni, and Zn, and whose Mn content is 0.1288 percent by mass or higher, or a magnetic body which is made of a ferrite material containing Fe, Ni, Zn, and Cu, and whose Mn content is 0.1178 percent by mass or higher, an iron oxide powder whose Mn content is 0.20 percent by mass or higher is used as a raw material powder.

When manufacturing a magnetic body whose primary component is Ni—Zn ferrite, an iron oxide powder whose Mn content is 0.20 to 0.85 percent by mass is used as a raw material powder, or, in addition to using an iron oxide powder whose Mn content is 0.20 percent by mass or higher as a raw material powder, a mol ratio of Ni to Zn (Ni/Zn) in the ferrite material is determined based on the Mn content in the iron oxide powder and the raw material powders are compounded in such a way that the mol ratio is achieved. The magnetic body does not contain any additives as essential components other than the primary components of the Ni—Zn ferrite material. A coil component using the magnetic body has excellent direct-current superimposition property and magnetic permeability.

A positive electrode active material precursor for a secondary battery, which is a secondary particle in which primary particles are aggregated, includes a core portion including nickel (Ni), cobalt (Co), and manganese (Mn), and a shell portion surrounding a surface of the core portion and including nickel (Ni), cobalt (Co), manganese (Mn), and aluminum (Al), wherein the core portion and the shell portion has rod-shaped primary particles, and an average major axis length of the primary particles of the shell portion is smaller than an average major axis length of the primary particles of the core portion. A method of preparing the positive electrode active material precursor, and a positive electrode active material prepared by using the positive electrode active material precursor are also provided.

Provided is a positive electrode active material for a non-aqueous electrolyte secondary battery. Also provided is a method for producing a positive electrode active material for a non-aqueous electrolyte secondary battery, comprising: providing a lithium transition metal composite oxide having a ratio D.sub.50/D.sub.SEM of 1 or more and 4 or less, having a layered structure, and having a ratio of a number of moles of nickel to a total number of moles of metals other than lithium of 0.3 or more and less than 1, and a ratio of a number of moles of cobalt to the total number of moles of metals other than lithium of 0 or more and less than 0.5; bringing the lithium transition metal composite oxide into contact with a cobalt compound to obtain an adhered material; and heat-treating the adhered material at a temperature higher than 700° C. and lower than 1100° C.

A composition and a solid material is especially suitable for the manufacture of an antenna adapted to operate in the very high frequency and ultra high frequency or V/UHF band. The composition has the formula Ni.sub.aZn.sub.bCu.sub.cCo.sub.dFe.sub.2-δO.sub.4, in which 2(a+b+c+d)+3(2−δ)=8, 0.05<b<0.5, e.g. 0.1<b<0.5, e.g. 0.1<b<0.4, e.g. 0.15<b<0.35, 0.10<c<0.25, preferably 0.15<c<0.25, alternatively c is 0.20, 0.04<d<0.25, preferably 0.06<d<0.25, and more preferably 0.07<d<0.25, and δ<0.05.

The present invention pertains to: a positive electrode active material precursor containing first secondary particle composed of an aggregate of a plurality of first primary particles, the positive electrode active material precursor including a first center portion represented by chemical formula 1 and a first surface portion represented by chemical formula 2, wherein the thickness of the first surface portion is 2-20% of the average radius of the positive electrode active material precursor; and a positive electrode active material containing the positive electrode active material precursor.

The present disclosure relates to a negative temperature coefficient product comprising an electrically conductive percolation network of printable NTC material as particles in a cross-linked dielectric polymer matrix and to a method of manufacturing thereof. The particles comprising a spinel phase, preferably a C-spinel phase, having a general formula M.sub.3O.sub.4 comprising at least a first metal M.sup.I that is manganese and second metal M.sup.II that is nickel. In addition the particles include a nickel oxide phase. The printable NTC material can be dispersed in a printable NTC ink comprising a dispersant, from which the NTC product, e.g. a thermistor, can be formed, e.g., after drying of the dispersant. During processing the ink is kept at a temperature below 300° C. Optionally, the spinel phase comprises a further metal M.sup.III. The weight fraction of nickel oxide with respect to the overall mass of the printable NTC material is preferably in a range between one and twenty weight percent.

This positive electrode active material for a non-aqueous electrolyte secondary battery contains a lithium transition metal complex oxide capable of occluding and releasing Li. The lithium transition metal complex oxide is represented by general formula Li.sub.xM1.sub.yO.sub.zF.sub.w (in the formula, 0.5 ≤ × < 3.1, 1 ≤ y ≤ 2, 2 ≤ z+w ≤ 4, and M1 is at least one element selected from Ni, Co, Mn, Ti, Fe, Al, Ge, Si, and Nb), and M2 (M2 being at least one element selected from Ca, Sr, Sc, Er, Y, Zr, and W) is included in the interior of secondary particles of the lithium transition metal complex oxide.