A positive electrode for an all-solid secondary battery, comprising a positive electrode active material expressed by A.sub.2S.AX, wherein

A is an alkali metal; and

X is selected from I, Br, Cl, F, BF.sub.4, BH.sub.4, SO.sub.4, BO.sub.3, PO.sub.4, O, Se, N, P, As, Sb, PF.sub.6, AsF.sub.6, ClO.sub.4, NO.sub.3, CO.sub.3, CF.sub.3SO.sub.3, CF.sub.3COO, N(SO.sub.2F).sub.2 and N(CF.sub.3SO.sub.2).sub.2.

The present invention generally relates to P2-type layered materials for electrochemical devices such as Na-ion batteries with high rate performance, and methods of making or using such materials. In some embodiments, the P2-type layered material has the chemical formula Na.sub.X(Mn.sub.QFe.sub.RCo.sub.T)O.sub.2. The P2-type layered material may be synthesized, for example, by a solid state reaction. In some cases, the P2-type layered material may be used as an electrode in an electrochemical device. The electrochemical device may have higher initial discharge capacities at various charge/discharge rates in galvanostatic testing compared with the initial discharge capacities of other P2-type layered materials.

The present invention relates to a lithium composite metal oxide which satisfies the requirements (1) and (2) described below. Requirement (1): The ratio of the half width A of the diffraction peak within the range of 2θ=64.5±1° to the half width B of the diffraction peak within the range of 2θ=44.4±1°, namely A/B is from 1.39 to 1.75 (inclusive) in powder X-ray diffractometry using a Cu-Kα ray. Requirement (2): The ratio of the volume-based 90% cumulative particle size (D.sub.90) to the volume-based 10% cumulative particle size (D.sub.10), namely D.sub.90/D.sub.10 is 3 or more.

Provided are a positive active material, a positive electrode including the same, and a lithium secondary battery including the positive electrode. The positive active material includes lithium cobalt oxide containing a metal element, and the lithium cobalt oxide containing a metal element has a ratio of a peak intensity of the O3 phase to a peak intensity of the H1-3 phase, I.sub.O3/I.sub.H1-3, that is greater than 1 in a X-ray diffraction (XRD) analysis spectrum using Cu-Kα radiation. Accordingly, a lithium secondary battery including the positive active material may have improved lifespan characteristics even at a high voltage.

A method for producing a lithium-containing composite oxide, the method including: a first step of preparing a lithium hydroxide; a second step of heating a hydroxide containing nickel and a metal M1 other than lithium and nickel to 300° C. or higher and 800° C. or lower, to obtain a composite oxide containing the nickel and the metal M; a third step of mixing the lithium hydroxide and the composite oxide, to obtain a mixture; a fourth step of compression-molding the mixture, to obtain a molded body; and a fifth step of baking the molded body at 600° C. or higher and 850° C. or lower, to obtain a baked body.

A carbonate precursor compound for manufacturing a lithium metal (M)-oxide powder usable as an active positive electrode material in lithium-ion batteries, M comprising 20 to 90 mol % Ni, 10 to 70 mol % Mn and 10 to 40 mol % Co, the precursor further comprising a sodium and sulfur impurity, wherein the sodium to sulfur molar ratio (Na/S) is 0.4<Na/S<2. Theslithium metal (M)-oxide powder has a particle size distribution with 10 μm≦D50≦20 μm, a specific surface with 0.9≦BET≦5, the BET being expressed in g/cm2, the powder further comprises a sodium and sulfur impurity, wherein the sum (2* Nawt)+Swt of the sodium (Nawt) and sulfur (S wt) content expressed in wt % is more than 0.4 wt % and less than 1.6 wt %, and wherein the sodium to sulfur molar ratio (Na/S) is 0.4<Na/S<2.

The present invention provided a positive electrode active material for a lithium secondary battery including lithium cobalt oxide particles. The lithium cobalt oxide particles include lithium deficient lithium cobalt oxide having Li/Co molar ratio of less than 1, belongs to an Fd-3m space group, and having a cubic crystal structure, in surface of the particle and in a region corresponding to a distance from 0% to less than 100% from the surface of the particle relative to a distance (r) from the surface to the center of the particle. In the positive electrode active material for a lithium secondary battery according to the present invention, the intercalation and deintercalation of lithium at the surface of a particle may be easy, and the output property and rate characteristic may be improved when applied to a battery.

To provide a lithium ion conductive crystal body having a high density and a large length and an all-solid state lithium ion secondary battery containing the lithium ion conductive crystal body. A Li.sub.5La.sub.3Ta.sub.2O.sub.12 crystal body, which is one example of the lithium ion conductive crystal body, has a relative density of 99% or more, belongs to a cubic system, has a garnet-related type structure, and has a length of 2 cm or more. The Li.sub.5La.sub.3Ta.sub.2O.sub.12 crystal body is grown by a melting method employing a Li.sub.5La.sub.3Ta.sub.2O.sub.12 polycrystal body as a raw material. With the growing method, a Li.sub.5La.sub.3Ta.sub.2O.sub.12 crystal body having a relative density of 100% can also be obtained. In addition, the all-solid state lithium ion secondary battery has a positive electrode, a negative electrode, and a solid electrolyte, in which the solid electrolyte contains the lithium ion conductive crystal body.

Provided is a new 5 V class spinel-type lithium manganese-containing composite oxide which enables the expansion of a high potential capacity region and the suppression of gas generation. The 5 V class spinel-type lithium manganese-containing composite oxide has an operating potential of 4.5 V or more at a metal Li reference potential, and contains Li, Mn, O and two or more other elements. The spinel-type lithium manganese-containing composite oxide is characterized in that, in an electronic diffraction image from a transmission electron microscope (TEM), a diffraction spot observed in the Fd-3m structure as well as a diffraction spot not observed in the Fd-3m structure are confirmed.

Disclosed are an electrode active material for lithium secondary batteries, comprising at least one selected from compounds represented by the following formula 1, and a lithium secondary battery comprising the same.
Li.sub.xMo.sub.4−yM.sub.yO.sub.6−zA.sub.z  (1) wherein 0≦x≦2, 0≦y≦0.5, 0≦z≦0.5, M is a metal or transition metal cation having an oxidation number of +2 to +4, and A is a negative monovalent or negative bivalent anion.