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.

Provided are a cobalt-free positive electrode material for a lithium ion battery, a preparation method therefor and a lithium ion battery. The method for preparing the cobalt-free positive electrode material for the lithium ion battery comprises: mixing lithium nickel manganese oxide with sulfate, so as to obtain a first mixture; and reacting the first mixture at a predetermined temperature, so as to obtain the cobalt-free positive electrode material. The cobalt-free positive electrode material comprises lithium nickel manganese oxide and a cladding layer of an outer surface thereof, and the cladding layer comprises lithium sulphate. The lithium ion battery comprises the cobalt-free positive electrode material. The cobalt-free positive electrode material has a relatively high electrical performance and a relatively low alkali content.

A lithium metal composite oxide having a layered structure, including at least lithium and an element X, wherein:the element X is at least one element selected from the group consisting of Co, Mn, Fe, Cu, Ti, Mg, Al, W, Mo, Nb, Zn, Sn, Zr, Ga, V, B, Si, S and P; the lithium metal composite oxide contains single particles and satisfies all of requirements (1) to (5):(1): a volume-based 50% cumulative particle size D.sub.50 of the lithium metal composite oxide is 2 μm or more and 10 μm or less; (2): the single particles have, on at least a part of surfaces thereof, adhered fine particles, with the proviso that a maximum particle size of the adhered fine particles is smaller than a particle size of the single particles; (3): the particle size of the single particles is 0.2 to 1.5 times D.sub.50 of the lithium metal composite oxide; (4): a particle size of the adhered fine particles is 0.01 to 0.1 times the D.sub.50 of the lithium metal composite oxide; and (5): an average number of the adhered fine particles adhered per particle of the single particles is 1 or more and 30 or less as measured with respect to a range observable in an image obtained by scanning electron microscope.

Embodiments of the present invention relate to a cathode active material, a method for manufacturing the same, and a lithium secondary battery including the same.

According to an embodiment, a cathode active material can be provided, the cathode active material comprising: a lithium metal oxide including a core and a shell disposed on a surface of the core; and a coating layer disposed on a surface of the lithium metal oxide, wherein a c value that satisfies Equation 1 and is in a range of 0.3 to 0.7, and the core and the shell have a layered crystalline structure.

c=b/a  [Equation 1]

(in Equation 1, a is a peak at 530 to 533 eV and b is a peak at 528 to 531 eV in an XPS spectrum of the coating layer)

Provided are a positive electrode active material for a lithium secondary battery, a method of preparing the same, and a lithium secondary battery including the same.

According to an exemplary embodiment, a positive electrode active material for a lithium secondary battery which includes lithium metal oxide particles and a coating layer placed on at least a part of a surface of the lithium metal oxide particles may be provided, wherein the coating layer includes B, LiOH, Li.sub.2CO.sub.3, and Li.sub.2SO.sub.4.

The present exemplary embodiments relate to a positive electrode active material and a lithium secondary battery including the same. The positive active material for a lithium secondary battery according to an exemplary embodiment includes lithium metal oxide particles including lithium, nickel, cobalt, manganese and doping elements, and includes a first domain and a second domain inside the lithium metal oxide particles.

Provided are a hierarchical porous ZSM-5 molecular sieve and a preparation method therefor. The molecular sieve comprises micropores and mesopores, wherein the pore size of the micropores is 0.5-1.8 nm, the pore size of the mesopores is 4-30 nm, and the particle size is 0.3-4 μm. The molecular sieve is prepared by using a hemicellulose as a hard template agent. Also provided are a hierarchical porous HZSM-5 molecular sieve, which is obtained by subjecting the ZSM-5 molecular sieve to ion exchange with an ammonium chloride solution, and the use of ZSM-5 and HZSM-5 molecular sieves in the preparation of a sound-absorbing material, the sound-absorbing material made from the molecular sieve, and a speaker loaded with the sound-absorbing material. After being prepared into sound-absorbing particles, the molecular sieve can more effectively improve the absorption and desorption performances of air molecules, improve the low-frequency response of a speaker, improve the acoustic performance of the speaker, and improve the acoustic improvement stability of sound-absorbing particles in the speaker.

The present exemplary embodiments relate to a positive electrode active material, a manufacturing method thereof, and a lithium secondary battery including the same. A positive active material for a lithium secondary battery according to an exemplary embodiment is a lithium metal oxide particle in the form of secondary particles including a plurality of primary particles: a first coating layer positioned on at least a part of the surface of the primary particle, and a second coating layer positioned over at least a portion of the secondary particle surface, the first coating layer comprising a first niobium compound, the second coating layer comprising the first niobium compound and a second niobium compound having a composition different from the first niobium compound.

A positive electrode active material for an all-solid-state lithium ion secondary battery, containing: a lithium-metal composite oxide particle having a niobium solid solution layer and a center other than the niobium solid solution layer; and a coating layer coating at least a part of a surface of the lithium-metal composite oxide particle and formed of a compound containing lithium and niobium, an average thickness of the coating layer is 2 nm or more and 1 μm or less, and an average thickness of the niobium solid solution layer is 0.5 nm or more and 20 nm or less.

A ferrite sintered magnet comprising an M type Sr ferrite having a hexagonal structure as a main phase, wherein the ferrite sintered magnet comprises La and Co, a content of B is 0.005 to 0.9% by mass in terms of B.sub.2O.sub.3, a content of Zn is 0.01 to 1.2% by mass in terms of ZnO, and the ferrite sintered magnet satisfies [La]/[Zn]≤0.79 and [Co]/[Zn]≤0.67 when an atomic concentration of La is represented by [La], an atomic concentration of Co is represented by [Co], and an atomic concentration of Zn is represented by [Zn].